tag:blogger.com,1999:blog-27034526709503998452024-03-28T05:23:34.892+05:30Basic Concept of Invertebrate Zoology KnowledgeIt's all about of Zoology Invertebrate theory for yourself by a simple & Easy language.
Gain your Knowledge and Spreads others. RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.comBlogger32125tag:blogger.com,1999:blog-2703452670950399845.post-41671228683469918812013-05-20T02:10:00.002+05:302021-05-21T04:32:20.859+05:30Affinities and Systematic Position of Balanoglossus with Chordate<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<h2>
<span style="font-size: x-large;"><i><u>Affinities with chordates</u></i></span> :-</h2>
<div>
<br /></div>
<div>
<h3>
(a) <i><u><span style="font-size: large;">Similarities</span></u></i> :-</h3>
</div>
<div>
<br /></div>
<div>
(i) Pharyngotremy (pharyngeal gill-slits) → Present</div>
<div>
<br /></div>
<div>
(ii) Central Nervous System → Comparable to dorsal tubular nerve cord.</div>
<div>
<br /></div>
<div>
(iii) Stomochord → Comparable to Notochord.</div>
<div>
<br /></div>
<div>
(iv) Enterocoelic coelom → Present.</div>
<div>
<br /></div>
<div>
<h3>
(b) <i><u><span style="font-size: large;">Objection </span></u></i>:-</h3>
</div>
<div>
<br /></div>
<div>
<table align="left" border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; margin-left: 6.75pt; margin-right: 6.75pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-table-anchor-horizontal: margin; mso-table-anchor-vertical: margin; mso-table-left: left; mso-table-lspace: 9.0pt; mso-table-rspace: 9.0pt; mso-table-top: 10.15pt; mso-yfti-tbllook: 1184;">
<tbody>
<tr style="height: 16.9pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td style="border: 1pt solid black; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
<span style="font-size: 13.5pt;">
Features</span><o:p></o:p></div>
</td>
<td style="border-left: none; border: 1pt solid black; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
<span class="apple-converted-space"><span style="font-size: 13.5pt;"> </span></span><span style="font-size: 13.5pt;">Balanoglossus</span><o:p></o:p></div>
</td>
<td style="border-left: none; border: 1pt solid black; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
<span class="apple-converted-space"><span style="font-size: 13.5pt;"> </span></span><span style="font-size: 13.5pt;"> Chordates</span><o:p></o:p></div>
</td>
</tr>
<tr style="height: 16.9pt; mso-yfti-irow: 1;">
<td style="border-top: none; border: 1pt solid black; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Notochord<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Not true<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
True<o:p></o:p></div>
</td>
</tr>
<tr style="height: 16.9pt; mso-yfti-irow: 2;">
<td style="border-top: none; border: 1pt solid black; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Morphology<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Short,
hollow, stifftube<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 16.9pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Solid,
rod like<o:p></o:p></div>
</td>
</tr>
<tr style="height: 33pt; mso-yfti-irow: 3;">
<td style="border-top: none; border: 1pt solid black; height: 33pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213">Composed of
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 33pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Tall
vacuolated endodermal cell<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 33pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Arranged
vacuole mesodermal cells<o:p></o:p></div>
</td>
</tr>
<tr style="height: 26.6pt; mso-yfti-irow: 4;">
<td style="border-top: none; border: 1pt solid black; height: 26.6pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Origin <o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 26.6pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Endodermal as a buccal diverticulam<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 26.6pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Mesodermal<o:p></o:p></div>
</td>
</tr>
<tr style="height: 13.7pt; mso-yfti-irow: 5;">
<td style="border-top: none; border: 1pt solid black; height: 13.7pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Surrounded by<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 13.7pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Besement membrane<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 13.7pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Primary & secondary sheathes<o:p></o:p></div>
</td>
</tr>
<tr style="height: 13.35pt; mso-yfti-irow: 6;">
<td style="border-top: none; border: 1pt solid black; height: 13.35pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Position <o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 13.35pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Ventral to dorsal blood vessel<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 13.35pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Dorsal to dorsal blood vessel<o:p></o:p></div>
</td>
</tr>
<tr style="height: 13.35pt; mso-yfti-irow: 7; mso-yfti-lastrow: yes;">
<td style="border-top: none; border: 1pt solid black; height: 13.35pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Supporting Function<o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 13.35pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent <o:p></o:p></div>
</td>
<td style="border-bottom: 1pt solid black; border-left: none; border-right: 1pt solid black; border-top: none; height: 13.35pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present<o:p></o:p></div>
</td>
</tr>
</tbody></table>
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184;"><tbody></tbody></table>
</div>
<div>
<br /></div>
<div>
<h3>
<i><u>Remark</u></i> :-</h3>
</div>
<div>
<br /></div>
<div>
(1) Barrington and Hyman called the buccal diverticulam as stomochord instead of notochord. They also rejected the idea of persistant notochord in Balanoglossus.</div>
<div>
<br /></div>
<div>
(2) <b><u>Central Nervous System</u></b> :- More similar to invertebrate type (Barrington,1965) than any true chordates, as :</div>
<div>
<br /></div>
<div>
(i) Nerve cord- Intraepidermal.</div>
<div>
<br /></div>
<div>
(ii) Nerve ring- Circumcentric.</div>
<div>
<br /></div>
<div>
(iii) Ventral nerve cord- Solid</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(3) <b><u>Pharyngotremy</u> </b>:- The only Chordates feature might be a convergent feature, as conceived by Beril (1955).</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(4) <b><u>Other Features</u></b> :- </div>
<div>
<br /></div>
<div>
(i) Post anal tail- Absent</div>
<div>
<br /></div>
<div>
(ii) Vascular System- Without centralised heart.</div>
<div>
<br /></div>
<div>
(iii) Endostyle- Absent</div>
<div>
<br /></div>
<div>
(iv) Gut- Undifferentiated, without muscular wall, no peristasis.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<h3>
<i><u>Remark</u></i> :-</h3>
</div>
<div>
<br /></div>
<div>
Resemblances are superficial and such when due to evolutionary convergence in the same track. Features indicate Hemichordates are definition lower in rank than true Chordates ( Uro- & Cephalo-chordates). Hemichordates thus very remotely connected with the central stock from which true chordates descended.</div>
<div>
<br /></div>
<div>
<div><script type='text/javascript'></div><div>(function(d) {</div><div><span style="white-space: pre;"> </span>var params = { bvpushsubid: 1323609, cb: (new Date()).getTime() };</div><div><span style="white-space: pre;"> </span>var qs = Object.keys(params).reduce(function(a, k){ a.push(k + '=' + encodeURIComponent(params[k])); return a},[]).join(String.fromCharCode(38));</div><div><span style="white-space: pre;"> </span>var s = d.createElement('script'); s.type='text/javascript';s.async=true;</div><div><span style="white-space: pre;"> </span>var p = 'https:' == document.location.protocol ? 'https' : 'http';</div><div><span style="white-space: pre;"> </span>s.src = p + "://cdn.hyperpromote.com/bidvertiser/tags/activejs/bdpush.js?" + qs;</div><div><span style="white-space: pre;"> </span>d.getElementsByTagName('body').item(0).appendChild(s);</div><div>})(document);</div><div></script></div></div><div><br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!--Begin BidVertiser code-->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!--End BidVertiser code-->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com2tag:blogger.com,1999:blog-2703452670950399845.post-81636274125588103732013-05-20T00:57:00.003+05:302013-06-13T12:36:46.585+05:30Affinities and Systematic Position of Balanoglossus With non-chordate<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<br />
<h2>
<span style="font-size: x-large;"><i><u>Affinities with non-chordates</u></i></span> :-</h2>
<div>
<br /></div>
<h2>
(B) <i><u>With Pogonophora</u></i> :-</h2>
<h3>
(a) <i><u><span style="font-size: large;">Similarities</span></u></i> :-</h3>
<div>
<br /></div>
<div>
<div>
(i) Coelom → Enterocoelic<br />
<br />
(ii) Nervous system → Intraepidermal<br />
<br />
(iii) Gonads → In trunk region<br />
<br />
(iv) Pericardial sac → Present<br />
<br />
<br />
<h3>
(b) <i><u><span style="font-size: large;">Dissimilarities</span></u></i> :-</h3>
<div>
<br /></div>
<div>
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184;"><tbody>
<tr style="height: 18.85pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;"><td style="border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Features<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Balanoglossus<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Pogonophora<o:p></o:p></div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 1;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Main nervous system<br />
concentrated at<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Mesosoma</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Protosoma</div>
</td></tr>
<tr style="height: 17.05pt; mso-yfti-irow: 2;"><td style="border-top: none; border: solid black 1.0pt; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Coelomoducts<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present</div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 3;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Alimentary canal<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent<o:p></o:p></div>
</td></tr>
</tbody></table>
<br /></div>
<div>
<h3>
<i><u>Remark</u></i> :-</h3>
</div>
<div>
<br /></div>
<div>
Young (1983) opposed the resemblances between the two groups (as stated by Barington,1965; Parker and Haswell, 1972; and Mc Ferland et al, 1985), claiming the similarities are superficial.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<h2>
<span style="font-size: x-large;"><i><u>Affinities with non-chordates</u></i></span> :-</h2>
<div>
<br /></div>
<h2>
(B) <i><u>With Echinodermata</u></i> :-</h2>
<h3>
(a) <i><u><span style="font-size: large;">Similarities</span></u></i> :-</h3>
<div>
<br /></div>
<div>
<h4>
(i) <i><u>In Adult Form</u></i> :-</h4>
</div>
</div>
<div>
<br /></div>
</div>
<div>
(i) Coelom → Divisible in 3 successive parts anterior-posteriorly.<br />
<br />
(ii) Nervous Plexux → Subepithelial<br />
<br />
<br />
<div>
<h4>
(ii)<i><u> In Larval Form</u></i> :- </h4>
</div>
<div>
<br /></div>
<div>
Tornaria resembles Bipinaria in.</div>
<div>
<br /></div>
<div>
(i) Pre-oral ciliated bands → Present</div>
<div>
<br /></div>
<div>
(ii) Cleavage → Holoblastic & equal</div>
<div>
<br /></div>
<div>
(iii) Apical Plate → With a turf of cilia.</div>
<div>
<br /></div>
<div>
(iv) Blastopore → Become Anus in adult.<br />
<br />
(v) Enterocoelic coelom → Present.<br />
<br />
<br />
<br />
<div>
<h3>
(b) <i><u><span style="font-size: large;">Dissimilarities</span></u></i> :-</h3>
</div>
<div>
<br /></div>
<div>
<h4>
(i) <i><u>In Adult Form</u></i> :-</h4>
</div>
<div>
<br /></div>
<div>
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184;"><tbody>
<tr style="height: 18.85pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;"><td style="border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Features<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Balanoglossus<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Echinodermata<o:p></o:p></div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 1;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Water vascular system<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present</div>
</td></tr>
<tr style="height: 17.05pt; mso-yfti-irow: 2;"><td style="border-top: none; border: solid black 1.0pt; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Pharyngeal gill slits<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent<o:p></o:p></div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 3;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Stomochord<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent</div>
</td></tr>
</tbody></table>
<br />
<div>
<div>
<h4>
(ii) <i><u>In Larval Form</u></i> :- </h4>
</div>
<div>
<br /></div>
<div>
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184;"><tbody>
<tr style="height: 18.85pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;"><td style="border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Features<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
<o:p></o:p>Balanoglossus</div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Echinoderms<o:p></o:p></div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 1;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Eye-spot in apical plate</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent</div>
</td></tr>
<tr style="height: 17.05pt; mso-yfti-irow: 2;"><td style="border-top: none; border: solid black 1.0pt; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Telotroch</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent</div>
</td></tr>
</tbody></table>
</div>
<div>
</div>
</div>
<div>
<br /></div>
<div>
<h3>
<i><u>Remark</u></i> :-</h3>
</div>
<div>
<br /></div>
<div>
Based on resemblances; Hemichordates & Echinoderms are thought to be originated from some common remote ancestor (Hymen,1959) and Barrington,1965). H.B fell (1963) denied it on the ground that similarities were due to larval convergence in similar mode of living.</div>
<div>
<br /></div>
<div>
<br /></div>
</div>
</div>
<div>
<br /></div>
<div>
</div>
</div>
<div>
</div>
</div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-23339956295038538912013-05-17T21:36:00.002+05:302013-06-13T12:37:34.991+05:30Short type Questions with Answers from Invertebrate<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h4 style="text-align: left;">
(21) <i><u>Name two aquatic respiratory structures of the arthropods ? Cite example.</u></i></h4>
<br />
(Ans) :- Gills, lining of the branchiostegite, epipodite.<br />
Found in Crustaceans.<br />
<br />
<h4 style="text-align: left;">
(22) <i><u>Name one Poiferan animal where spicules are absent. Mention the subclass of that animal ?</u></i></h4>
<br />
(Ans) :- In Oscarella spicules are absent.<br />
Subclass- Tetractinellida.<br />
<br />
<h4 style="text-align: left;">
(23) <i><u>Mention the characteristic features of nervous system of Chiton ?</u></i></h4>
<br />
(Ans) :- Protoneurous condition where the nervous system is without any definite ganglionic function.<br />
<br />
<h4 style="text-align: left;">
(24) <i><u>State the functions of Tiedman's body & Pollian vessicle ?</u></i></h4>
<br />
(Ans) :- Tiedman's body may produce coelomocytes.<br />
Pollian vessicle are apparently for fluid storage.<br />
<br />
<br />
<h4 style="text-align: left;">
(25) <i><u>What is Atoll ?</u></i></h4>
<br />
<br />
(Ans) :- Atolls are reefs that encircle a lagoon but not an island. These types of reefs typically slope rather steeply into the deep water at their seaward edge.<br />
<br />
<h4 style="text-align: left;">
(26) <i><u>Why pulmonatans are so named ? Cite an example.</u></i></h4>
<br />
(Ans) :- In this molluscs true gill absent & respiration is done by pulmonary sac or lung, as the pulmonary sac is respiratory organ so they are named as pulmonatans. Mantle cavity form the pulmonary chamber, the inner surface of which is highly vascularised.<br />
<br />
<i><u>Example</u></i> :- Achatina fulica<br />
<br />
<h4 style="text-align: left;">
(27) <i><u>What is Mesenchyme ?</u></i></h4>
<br />
(Ans) :- Embryonic connective tissue ; irregular or amoebocytic cells often embeded in gelatinous matrix, prominant in poriferan animals.<br />
<br />
<h4 style="text-align: left;">
(28) <i><u>What is Ampulla ?</u></i></h4>
<br />
(Ans) :- Membranous vesicle ; dialation at the end of each semicircular canal containing sessory epithilum, muscular vesicle above tube feet in water vascular system of echinoderm.<br />
<br />
<h4 style="text-align: left;">
(29) <i><u>What do you mean by Coenosarc ?</u></i></h4>
<br />
(Ans) :- Within the stems of colonial polyp, material that like links the individuals, containing the gastrovascular cavity & surrounded by the perisarc.<br />
<br />
<h4 style="text-align: left;">
(30) <u><i>What is Kinetodesma ?</i></u></h4>
<br />
(Ans) :- Fibril arising from the kinetosome of a cilium in ciliate Protozoan & passing along the kinetosomes of cilia in that same row is known as kinetodesma. All the kinetosome & kinetodesmata of a row of cilia is named as kinety.<br />
<br />
<h4 style="text-align: left;">
(31) <i><u>What is Cilium ?</u></i></h4>
<br />
(Ans) :- A hair like vibratil organelle process found on many animal cells. Cilia may be used in moving particles along the cell surface or in ciliate protozoans for locomotion. Each cilium contains nine pairs of longitudinal microtubule arranged in a circle arround a central pair "9+2" tube of microtubules in cilium is it's axoneme.<br />
<br />
<h4 style="text-align: left;">
(32) <i><u>In which phylum do you find a mantle ? Where does the mantle originate from ?</u></i></h4>
<br />
(Ans) :- In phylum mollusca mantle is found. Two folds of skin, outgrowths of the dorsal body wall, form a protective mantle.<br />
Mantle is responsible for the secretion of the shell.<br />
<br />
<h4 style="text-align: left;">
(33) <i><u>Name the different types of pseudopodia & state their characters with example.</u></i></h4>
<br />
(Ans) :- (i) Lobopodia- Large blunt extensions of the cell body containing both endoplasm & ectoplasm.<br />
<br />
(ii) Filopodia- are thin extensions, usually branching & containing only ectoplasm.<br />
<br />
(iii) Reticulopodia- repeatedly region to form a net like mesh.<br />
<br />
(iv) Axopodia- Long thin pseudopodia supported by axial rods of microtubules.<br />
<br />
<h4 style="text-align: left;">
(34) <i><u>Locomotion & function of Chlorogogen cells?</u></i></h4>
<br />
(Ans) :- In annelida coelomic fluid contain four types of corpuscles, chlorogogen cells are one type of coelomic crpuscles.<br />
<br />
<i><u>Function </u></i>:- Help in removal of excretory products out of body.<br />
<br /></div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-29275014842608308092013-05-17T18:22:00.006+05:302013-06-13T12:38:05.248+05:30Short type Questions with Answers from Invertebrate<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h4 style="text-align: left;">
(11) <i><u>In which animal Aristotle's Lantern found ? Mention its function.</u></i></h4>
<br />
(Ans) :- Aristotle's Lantern found in the class Ecinoidea, under the phylum Echinodermata(sea urchin).<br />
<br />
Function :- Acts as masticating apparatus to which teeth are attached.<br />
<br />
<h4 style="text-align: left;">
(12) <i><u>Write the scientific name of Portugueese-man-of war ? In which phylum does it belong ?</u></i></h4>
<br />
(Ans) :- Physalia physalis (phylum-Cnideria ; class-hydrozoa)<br />
<br />
<h4 style="text-align: left;">
(13) <i><u>Mention the utility of Byssus threads ?</u></i></h4>
<br />
(Ans) :- Bivalvia having strands of byssus by which the animals are often attached to the substratum or objects. A byssal gland is located in the foot sescretes a fluid protein which passes down a groove along the underside of the foot; the secretion hardens on exposure to sea water.<br />
<br />
<h4 style="text-align: left;">
(14) <i><u>What is Cnidoblast ?</u></i></h4>
<br />
(Ans) :- A round or oval. epidermal cell with a basal nucleus, typical of cnidaria, that contain nematocyst.<br />
<br />
<h4 style="text-align: left;">
(15) <i><u>What is Sclerosepta ?</u></i></h4>
<br />
(Ans) :- Each corallite consists of cup. The wall of cup enclosing the aboral position of the polyp is termed as theca. The ridges of the cup are called Skeletal septa or Sclerosepta. <br />
<br />
<h4 style="text-align: left;">
(16) <i><u>What is Biradial symmetry ? Cite an example of an animal having this type of symmetry.</u></i></h4>
<br />
(Ans) :- The arrangement of body components of an animal such that similar parts are located to either side of the central axis & each of the four sides of the body is identical to the oposite side but different from the adjacent side.<br />
Found in sea walnuts (ctenophora)<br />
<br />
<h4 style="text-align: left;">
(17) <i><u>Name two free living Platyhelminthes ?</u></i></h4>
<br />
(Ans) :- Planaria, Convoluta, Thysanozoon, Bipalium etc.<br />
<br />
<h4 style="text-align: left;">
(18) <i><u>Define metamerism ? give an example.</u></i></h4>
<br />
(Ans) :- Metamerism is a serial repetition of similar body segments along the longitudinal axis of the body. Each segment is called metamere or somite. It is found in the phylum Annelida.<br />
<br />
<h4 style="text-align: left;">
(19) <i><u>Give an example of animals having only polypoid & only medusoid characteristics ? Mention their respective classes.</u></i></h4>
<br />
(Ans) :- Polypoid- Metridium (class- Anthozoa) ;<br />
Medusoid- Aurelia aurita (class- Scyphozoa)<br />
<br />
<h4 style="text-align: left;">
(20) <i><u>Write the function of Madriporite ?</u></i></h4>
<br />
(Ans) :- Sieve like structure that is the intake for the water vascular system of echinoderm.In echinodermata a sieve like, button shaped process on the aboral surface of the body; through its opening the water vascular system is connected to the water outside.<br />
<br />
<br />
<br /></div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-72649687736241643662013-05-16T01:14:00.006+05:302013-06-13T12:38:32.493+05:30Short type Questions with Answers from Invertebrate<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h4 style="text-align: left;">
(1) <u><i>What is Cytopharynx</i></u> ?</h4>
<br />
(Ans) :- In some Protozoan cells, a short passage like region through which food passes after being ingested at the cytostome.<br />
<br />
<h4 style="text-align: left;">
(2) <u><i>What is Pseudocoelom & where it is found</i></u> ?</h4>
<br />
(Ans) :- A small second body cavity (the first being the gut) which occupies a space between the mesoderm of the body wall & the endoderm of the gut. There are no mesentaries suspending the internal organs & no muscular layers around the gut.<br />
Found in Nematohelminthes.<br />
<br />
<h4 style="text-align: left;">
(3)<i><u> What is Amoeboid movement</u></i> ?</h4>
<br />
(Ans) :- Movement in the fashion of Amoeba i.e. by Pseudopodia.<br />
<br />
<h4 style="text-align: left;">
(4) <i><u>What is contractile vacuole? Mention its function </u></i>?</h4>
<br />
(Ans) :- An organelle which appears to function in removal of excess water from the cells of Protozoa. The contractile vacuole expands as it fills with water from the cytoplasm & contracts as this water is emptied to the extertior.<br />
<br />
<i><u>Function</u></i> :- They are responsible for osmoregulation, i.e. maintenance of a constant water potential inside the body.<br />
<br />
<h4 style="text-align: left;">
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a> </h4>
<h4 style="text-align: left;">
(5) <i><u>What is Tracheoles ? Where they are found</u></i> ?</h4>
<br />
(Ans) :- One of the circular tubes that make up the respiratory system of an insect. The tracheae ramify throughout the body, terminating in fine, intracellular branches called Tracheoles.<br />
<br />
<h4 style="text-align: left;">
(6) <i><u>What is stone canal ? Where it is found ?</u></i></h4>
<br />
(Ans) :- In Echinoderm a canal with walls strengthened by calcarious matter that connect the madriporite with water vascular system.<br />
<br />
<h4 style="text-align: left;">
(7) <i><u>In which animal group Choanocytes are found ? Mention their function.</u></i></h4>
<br />
(Ans) :- One of the flagellated collar cells that line cavities & canals of sponges are called choanocytes.<br />
In Poriferan animal Choanocytes are found.<br />
<br />
<i><u>Functions</u></i> :- (a) Flagella of choanocytes maintain a current of environmental water through the canals(keep the water moving). (b) Trap & phagocytize food particles that are carried in the water.<br />
<br />
<h4 style="text-align: left;">
(8) <i><u>What is Medusa ?</u></i></h4>
<br />
(Ans) :- Medusa are usually free swimming stage in the life cycle of Cniderians. Medusa have bell shaped or umbrella shaped bodies & tetramerous symmetry, the mouth is usually centered on the concave side & tentacles extend from the rim of the umbrella.<br />
<br />
<h4 style="text-align: left;">
(9)<i><u> Name the different types of gills found in crustaceans?</u></i></h4>
<br />
(Ans) :- (a) Podobranch- attached with coxopodite of the thoracic appendage.<br />
(b) Arthrobranch- Attached with arthroidal membrane.<br />
(c) Pleurobranch- Attached with the lateral wall of the thorax.<br />
<br />
<h4 style="text-align: left;">
(10) <u><i>What is Radial Symmetry ? give example.</i></u></h4>
<br />
(Ans) :- Radial symmetry applies to the forms that can be devided into similar halves by more than two planespassing through the longitudinal axis.<br />
<br />
<i><u>Example</u></i> :- Spongs, Hydra, Jellyfish etc.<br />
<br />
</div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-73857227127376334802013-05-09T16:53:00.000+05:302013-06-13T12:39:19.871+05:30Affinities and Systematic Position of Balanoglossus with non-chordate<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="font-size: x-large;"><i><u>Affinities with non-chordates</u></i></span> :-</h2>
<h2 style="text-align: left;">
(B) <i><u>With Phoronida</u></i> :-</h2>
<h3 style="text-align: left;">
(a) <i><u><span style="font-size: large;">Similarities</span></u></i> :-</h3>
<div>
<br /></div>
<div>
<h4>
(i) <i><u>In Adult Form</u></i> :-</h4>
</div>
<div>
<br /></div>
<div>
(i) Body → Worm like</div>
<div>
<br /></div>
<div>
(ii) Mode of Feeding → Ciliary</div>
<div>
<br /></div>
<div>
(iii) Sense Organ → Absent</div>
<div>
<br /></div>
<div>
<h4>
(ii)<i><u> In Larval Form</u></i> :-</h4>
</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(i) Body → Spindle shaped; Transparent; Free-swimming;</div>
<div>
<br /></div>
<div>
(ii) Pre-oral cilia → Present</div>
<div>
<br /></div>
<div>
(iii) Coelomic Compartment → Five</div>
<div>
<br /></div>
<div>
(iv) Apical Plate → With a turf of cilia and eye spots.</div>
<div>
<br /></div>
<div>
(v) Blastopore → Become Anus in adult.</div>
<div>
<br /></div>
<div>
<h3>
(b) <i><u><span style="font-size: large;">Dissimilarities</span></u></i> :-</h3>
</div>
<div>
<br /></div>
<div>
<h4>
(i) <i><u>In Adult Form</u></i> :-</h4>
</div>
<div>
<br /></div>
<div>
<div>
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184;"><tbody>
<tr style="height: 18.85pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;"><td style="border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Features<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Balanoglossus<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Pheronida<o:p></o:p></div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 1;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Body<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Divisible into 3 parts</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Not so</div>
</td></tr>
<tr style="height: 17.05pt; mso-yfti-irow: 2;"><td style="border-top: none; border: solid black 1.0pt; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Pharyngeal gill slits<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent<o:p></o:p></div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 3;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Stomochord<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent<o:p></o:p></div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 4; mso-yfti-lastrow: yes;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Sexes</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Separate<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Not Separate<o:p></o:p></div>
</td></tr>
</tbody></table>
</div>
<div>
<br /></div>
<div>
<h4>
(ii) <i><u>In Larval Form</u></i> :- </h4>
</div>
<div>
<br /></div>
<div>
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184;"><tbody>
<tr style="height: 18.85pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;"><td style="border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Features<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Tornaria<o:p></o:p></div>
</td><td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Actinotrocha<o:p></o:p></div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 1;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Ciliated bands</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Pre-oral & Pre-anal</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Along the arms</div>
</td></tr>
<tr style="height: 17.05pt; mso-yfti-irow: 2;"><td style="border-top: none; border: solid black 1.0pt; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Arm like Projection</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent</div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present</div>
</td></tr>
<tr style="height: 17.95pt; mso-yfti-irow: 3; mso-yfti-lastrow: yes;"><td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Coelom formation<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Enterocoelic<o:p></o:p></div>
</td><td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Schizocoelic<o:p></o:p></div>
</td></tr>
</tbody></table>
</div>
<div>
</div>
</div>
<div>
<br /></div>
<div>
<h3>
<i><u>Remark</u></i> :-</h3>
</div>
<div>
<br /></div>
<div>
Similarities are so superficial that Balanoglosssus can not be grouped with Phoronids; as suggested by Goodrich at al.</div>
<div>
<br /></div>
<br /></div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-27758057809050441152013-05-08T21:56:00.001+05:302013-06-13T12:39:45.069+05:30Affinities and Systematic Position of Balanoglossus<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<span style="font-size: x-large;"><i><u>Affinities with non-chordates </u></i></span>:-</h2>
<h3 style="text-align: left;">
(A) <span style="font-size: x-large;"><i><u>With Annelida </u></i></span>:-</h3>
<h3 style="text-align: left;">
(a) <i><span style="font-size: large; text-decoration: underline;">Similarities</span><span style="font-size: x-large;"> </span></i>:-</h3>
<div>
<br /></div>
<h4 style="text-align: left;">
(i) <i><u>In Adult Form</u></i> :-</h4>
<div>
<br /></div>
<div>
(1) Body → elongated; vermiforms; coelomate;</div>
<div>
<br /></div>
<div>
(2) Heart → dorsal to gut.</div>
<div>
<br /></div>
<div>
(3) General Sense Organ → Absent</div>
<div>
<br /></div>
<div>
(4) Collar → Resembles to clitellum.</div>
<div>
<br /></div>
<div>
(5) Blood Vessel → Similar pattern.</div>
<div>
<br /></div>
<h4 style="text-align: left;">
(ii)<i><u> In Larval Form</u></i> :-</h4>
<h4 style="text-align: left;">
</h4>
<div>
Tornaria of Balanoglossus resembles Trochophore larva of anelids in :</div>
<div>
<br /></div>
<div>
(1) Body → Transparent and spindle-shaped.</div>
<div>
<br /></div>
<div>
(2) Habit → Free-swimming</div>
<div>
<br /></div>
<div>
(3) Ciliated bonds → Transverse</div>
<div>
<br /></div>
<div>
(4) Apical Plate → With a tuft of cilia and eye spots.</div>
<div>
<br /></div>
<h3 style="text-align: left;">
(b) <i><u><span style="font-size: large;">Dissimilarities</span></u></i> :-</h3>
<div>
<br /></div>
<h4 style="text-align: left;">
(i) <i><u>In Adult Form</u></i> :-</h4>
<div>
<br /></div>
<div>
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184;">
<tbody>
<tr style="height: 18.85pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td style="border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Features <o:p></o:p></div>
</td>
<td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Balanoglossus<o:p></o:p></div>
</td>
<td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Annelids<o:p></o:p></div>
</td>
</tr>
<tr style="height: 17.95pt; mso-yfti-irow: 1;">
<td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Body <o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Unannulated<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Annulated<o:p></o:p></div>
</td>
</tr>
<tr style="height: 17.05pt; mso-yfti-irow: 2;">
<td style="border-top: none; border: solid black 1.0pt; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Pharyngeal gill slits <o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent<o:p></o:p></div>
</td>
</tr>
<tr style="height: 17.95pt; mso-yfti-irow: 3;">
<td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Stomochord<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Present<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Absent<o:p></o:p></div>
</td>
</tr>
<tr style="height: 17.95pt; mso-yfti-irow: 4; mso-yfti-lastrow: yes;">
<td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Excretory organ<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Glomerulus<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Nephridia<o:p></o:p></div>
</td>
</tr>
</tbody></table>
</div>
<div>
<br /></div>
<h4 style="text-align: left;">
(ii) <i><u>In Larval Form</u></i> :- </h4>
<div>
<br /></div>
<div>
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-yfti-tbllook: 1184;">
<tbody>
<tr style="height: 18.85pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0;">
<td style="border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Features <o:p></o:p></div>
</td>
<td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Tornaria<o:p></o:p></div>
</td>
<td style="border-left: none; border: solid black 1.0pt; height: 18.85pt; mso-border-alt: solid black .5pt; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-themecolor: text1; mso-border-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Trochophore<o:p></o:p></div>
</td>
</tr>
<tr style="height: 17.95pt; mso-yfti-irow: 1;">
<td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Cleavage<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Equal<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Spiral<o:p></o:p></div>
</td>
</tr>
<tr style="height: 17.05pt; mso-yfti-irow: 2;">
<td style="border-top: none; border: solid black 1.0pt; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Blastula<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Hollow<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.05pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Solid<o:p></o:p></div>
</td>
</tr>
<tr style="height: 17.95pt; mso-yfti-irow: 3; mso-yfti-lastrow: yes;">
<td style="border-top: none; border: solid black 1.0pt; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Coelom formation<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Enterocoelic<o:p></o:p></div>
</td>
<td style="border-bottom: solid black 1.0pt; border-left: none; border-right: solid black 1.0pt; border-top: none; height: 17.95pt; mso-border-alt: solid black .5pt; mso-border-bottom-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-right-themecolor: text1; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; padding: 0in 5.4pt 0in 5.4pt; width: 159.6pt;" valign="top" width="213"><div class="MsoNormal" style="margin-bottom: 0.0001pt;">
Schizocoelic<o:p></o:p></div>
</td>
</tr>
</tbody></table>
</div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i><u>Remark</u></i> :- </h3>
<div>
<br /></div>
<div>
Dissimilarities are much more prominent than superficial similarities. Balanoglossus, thus, could not be grouped together with Annelids.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-28179392727678041332013-04-18T21:48:00.001+05:302013-06-13T12:40:26.272+05:30Types of Coelom<div dir="ltr" style="text-align: left;" trbidi="on">
<div style="text-align: left;">
A true coelom is lined on all sides by mesoderm which gives rise to muscles that surround the gut aas well as underlying the body wall. This allows more efficient digestion because food can be pushed through the digestive tract by muscles.</div>
<div style="text-align: left;">
<br /></div>
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;">True Coelom</span></u></i> :- </h2>
<div>
<br /></div>
<div>
Schizocoeloms are found in animals known as Protostomates.</div>
<div>
<br /></div>
<div>
Enterocoeloms are found in animals known as Deuterostomates.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;">Protostomia</span></u></i> :-</h2>
<div>
Cleavage is spiral. In spiral cleavage the first two divisions of the egg are equal, but the rest are unequal. These results into some small and some large cells, as it can be seen. The blastopore forms the mouth. The body cavity is formed by Schizocoely- Schicoely means that the body cavity is formed from blocks of mesoderm around the gut that enlarge and hollow out. The end result is a pair of coelomic cavities. Cleavage is determinate. This means that the fate of each individual cell is already established when it is formed. Each cell can only develop into a specific cell type.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;">Deuterostoma</span></u></i> :-</h2>
<div>
Cleavage is radial- Each cell division is equal and result in cells of all the same size. The blastopore does not form the mouth, it usually forms the anus. The body cavity is formed by enterocoely. Enterocoely is the formation of the body cavity by out pocketing of the primitive gut that break off and form the coelom. Cleavage is indeterminate. This means that the fate of each individual cell is not determined when it is formed and each cell can form one of many cell types. There are cavities , coeloms. that form and lie both outside (extraembryonic) and inside (intra-embryonic) the embryo during development. The intra-embryonic coelom is the cavity that lies within the developing embryo that will form the 3 major body cavities : Pericardial, Pleural. Peritoneal. The coelom forms very early in embryogenesis and is much later partitioned inferiorly by the diaphragm and pleura-peritoneal membrane ; and superiorly initially by the pleuro-pericardial fold between the heart and lungs. The intraembryonic coelom communicated through coelomic portals (at the level of midgut herniation) with the extraembryonic coelom. All cavities are fluid filled and developing organs push against a wall of the cavity, generating a double coat (serosal/adventital) surrounding an organ (for example the lungs). The serous membrane is the epithelium (squamous) and its associated underlying loose connective tissue.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;">Protostomes Vs Deuterostomes</span></u></i> :-</h2>
<div>
In echinoderms and chordates, for example, the anus forms first, and then the mouth. In animals belonging to several other important phyla, on the other hand, such as arthropodes, annelids and molluscs, the mouth forms first, followed by the anus. For this reason arthropods, annelids and molluscs are sometimes called Protostomes (Greek : proto = the first ; stoma = mouth ). It is also possible to take an most echinoderm or chrodate embryos at the 2-cell or 4-cell stage of development, separate the cells, and still have each cell continue on to develop into a complete, variable organism. This is not possible with protostome embryos. If they are separated at this stage, the cells will not develop into complete, viable organisms. For this reason, protostomes are said to display determinate cleavage, and deuterostomes are said to have indeterminate cleavage. You will be introduced in lecture and in subsequent laboratory exercises to other important developmental characteristics that distinguish protostomes from deuterostomes.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Advantage of a coelom</u></i> :- </h2>
<div>
(i) The hydrostatic skeleton a fluid body cavity provides a more rigid structure than mesoderm for muscles to pull against and thus be a more efficient skeletal support system.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(ii) Circulatory system : absorbed nutrients can be circulated around the body and metabolic wastes can be carried to the body surface more efficiently by fluid than by solid mesoderm.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Result- Faster locomotion and larger body size possible.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Advantage of Pseudocoelom</u></i> :- </h2>
<div>
In evolution, the pseudocoelom is a blatocoel (the space in the blastula) that is retained to adulthood. In addition to having a body cavity, organisms with pseudocoeloms also have a complete digestive tract separate opening for food to enter and undigested material to leave. This makes digestion and feeding more efficient because the animal can eat before it has finished digesting its previous meal. Organisms that have pseudocoeloms are not a monophyletic group (in other words, <b>the pseudocoelom</b> is a <b>homoplasious</b> character that occured more than once).</div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
</div>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-9329096262523269542013-04-12T02:15:00.000+05:302013-06-13T12:41:03.598+05:30Types of Coelom<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;"><br /></span></u></i></h2>
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;">Pseudocoelom</span></u></i> :-</h2>
<div>
In some protostomes, the embryonic blastocoele persists as a body cavity. These protostomes have a fluid filled main body cavity unlined or partially lined with tissue derived from mesoderm. This fluid-filled space surrounding the internal organs serves several functions like distribution of nutrients and removal of waste or supporting the body as a hydrostatic skeleton. A pseudocoelomate is any invertebrate animal with a three-layered body and a pseudocoel. Nematoda (roundworms), Rotifera (rotifers), Kinorhyncha, Nematomorpha, Nematomorphs or horsehair worms, Gastrotricha, Loricifera, Priapulida, Acanthocephala, spiny-headed worms, Aschelminth animals, Entoprocta are the examples of Pseudocoelomates. The coelom was apparently lost of reduced as a result of mutations in certain types of genes that affected early development. Thus, pseudocoelomates evolved from coelomates. Pseudocoelomate is no longer considered a valid taxonomic group, since it is not monophyletic. however, it is still usd as a descriptive term.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Important characteristics as the psudocoelomates are adated to survive that they lack a vascular blood system, as a diffusion and osmosis circulate nutrients and waste products throughout the body. They lack a skeleton hydrostatic pressure gives the body a supportive framework that acts as a skeleton. Furthermore they have no segmentation. Their body wall comprises of epidermis and muscle often syncytial usually covered by a secreted cuticle. They are mostly microscopic and chosen a parasite mode life (although some are free living ).</div>
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;">Acoelomate</span></u></i> :- </h2>
<div>
<br /></div>
<div>
Lacking a fluid filled body cavity presents some serious disadvantage. Fluids do not compress, while the tissue surrounding the organs of these animals will compress. Therefore, acoelomate organs are not protected from crushing forces applied to the animal's outer surface.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Organisms showing acoelomates formation include the platyhelminthes (flatworms, tapeworms, etc), the Cniderians (jellyfish and allies), and the Ctenophores (comb jellies). The coelom can be used for diffusion of gases and metabolites etc. These creatures do not have this need, as the surface area to volume ratio is large enough to allow absorption of nutrients and gas exchange by diffusion alone, due to dorsoventral flattening.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
The coelom is defined as a body cavity or space than runs the length of a vertebrate. It separates the body into an inner tube and an outer tube. the coelom forms when the lateral plate mesoderm splits.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;">Evolution of Coelomate Animals</span></u></i> :- </h2>
<div>
<br /></div>
<div>
In the Cniderian, the space between the ectoderm and endoderm tissue layers is filled with an acellular mesoglea. In the platyhelminth (flatworms) these mesoderm fills the space between mesoderm and the endoderm :</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
The advantage of the flatworm body plan is the superior pull muscles can make using solid mesoderm as a lever, versus gel-like mesoglea. But, body organs can not move freely but are embedded in solid mesoderm tissue. It is not more difficult for materials to move from the gut to the body wall. Probably to solve the problems the is to have some sort of body cavity, called a coelom, in which the body organs lie bathed in body fluid. Movement of the body wall would not squeeze the organs, organs could glow without being pressed by the body wall and diffusion of nutrients and wastes would be easier.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-30842268516256823372013-04-09T16:07:00.000+05:302013-06-13T12:41:31.548+05:30Introduction & Significance of Coelom<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><span style="font-size: x-large;">Introduction</span></u></i> :- </h2>
<div>
A coelom is a fluid-filled body cavity found in most animals which is located in the mesoderm, derived from the splanchnic mesoderm, the middle germ layer only found in tiploblastic (three-layered) organisms. Simpler animals like Cniderians (ex- Jelly fish, Coral etc ) and sponges are diploblastic and monoblastic respectively, lacking a coelom. Though the coelom developed in tiploblastic animals, some of these animals have lost their coeloms.</div>
<div>
<br /></div>
<div>
Animals with a coelom, including the majority of animal phyla, are called coelomates. Animals without a coelom, such as flatworms, are called acoelomates. In between there are some animals called pseudocoelomates, which possess a "false coelom," which is an unlined or partially lined body cavity between the gut and body wall.</div>
<div>
<br /></div>
<div>
The earliest known animal with a coelom is vernanimalcula guizhouena, which lived 600 million years ago, during the Ediacaran period. The biggest disadvantage of lacking a coelom is that the internal organs are much more susceptible to compression and damage. The protection that coelomate animals get from their body cavity stems from the fact that fluids are incompressible, while organs are not. Since the organs are surrounded by an incompressible fluid, they are well-protected in coelomates.</div>
<div>
<br /></div>
<div>
The coelomates nonchordate phyla comprise Entoprocta, Ectoprocta, Phoronida, Brachiopoda, Mollusca, Priapulida, Sipuncula, Echiura, Annelida, Tardigrada, Pentastoma, Onychophora, Arthropoda, Pogonophora, Echinodermata, Chaetognatha, Hemichordata.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
However, In contrast a lots of and numerous animals are pseudocoelomate, including nematodes, rotifers, kinorhynchans (mud dragon), nematomorphs (horsehair worms), gastrotrichs, loriciferans, priapulid worms, spiny-headed worms, and entoprocts. Many of these organisms are less than a millimeterin size, but some, like priapulid worms, grow as large as 6 inch (15 cm).</div>
<div>
<br /></div>
<div>
<h2 style="text-align: left;">
<i><u>Significance</u></i> :-</h2>
</div>
<div>
(i) A coelom is defined as a cavity that separates the gut from the body wall. The coelom allows the internal organs to shift around and develop independently of the body wall, creating more physiological and evolutionary flexibility. Though the coelom usually refers to the largest body cavity, coelomates animals may feature several strategically placed body cavities.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(ii) Organs formed inside a coelom can freely move, grow, and develop independently of the body wall while fluid cushions and protects them from shocks. Arthropods, mollusks even certain annelids have a reduced coelom. This condition in various ways may be compensated by other alternatives. As in former two groups principal body cavity is the hemocoel of an open circulatory system. In leeches the botrydoial tissue do the work as coelom is supposed to do.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(iii) In the past, zoologists grouped animals based on characters related to the coelom. The presence or absence of a coelom and the way in which it was formed was believed to be important in understanding the phylogenetic relationships of animal phyla. However, recent molecular phylogenies have suggested this characteristic is not as informative as previously believed : the coelom may have arisen twice, once in protostomes and once among the deuterostomes.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Formation</u></i> :- </h2>
<div>
Coelom formation begins in the gastrula stage. The developing degestive tube of an embryo forms as a blind pouch called the archenteron.</div>
<div>
<br /></div>
<div>
In Protostomes the coelom forms by a process known as schizocoely. The archenteron initially forms, and the mesoderm splits into two layers : the first attaches to the body wall or ectoderm, forming the parietal layer and the second surrounds the endoderm forming the visceral layer or alimentary canal. The space between the parietal layer and the visceral layer is known as the coelom or body cavity. In Deuterostomes, the coelom forms by enterocoely mesoderm buds from the walls of the archenteron and hollows to become the coelomic cavities.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Origins</u></i> :- </h2>
<div>
<h3 style="text-align: left;">
<ul style="text-align: left;">
<li>The Acoelomate Theories :</li>
</ul>
</h3>
</div>
<div style="text-align: left;">
<span style="font-size: 19px;"><b> </b>Coelom evolved from an acoelomate ancestor.</span></div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
</div>
<h4>
<ul style="text-align: left;">
<li><span style="font-size: 19px;">The Enterocoel Theory :</span></li>
</ul>
<div style="text-align: left;">
<span style="font-size: 19px;"><span style="font-weight: normal;">Coelom evolved from gastric pouches of Cniderian ancestors.</span></span></div>
<div style="text-align: left;">
<span style="font-size: 19px;"><span style="font-weight: normal;">Supported by research on flatworms and small worms recently discovered in marine fauna ("Coelom").</span></span></div>
<div style="text-align: left;">
<span style="font-size: 19px;"><span style="font-weight: normal;"><br /></span></span></div>
<div style="text-align: left;">
<span style="font-size: 19px;"><span style="font-weight: normal;"><br /></span></span></div>
<div style="text-align: left;">
<span style="font-size: 19px;"><span style="font-weight: normal;"><br /></span></span></div>
<div style="text-align: left;">
<span style="font-size: 19px;"><span style="font-weight: normal;"><br /></span></span></div>
</h4>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-66389206239847557992013-04-09T01:47:00.001+05:302013-06-13T12:41:58.827+05:30Types of Symmetry<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<u><i><br /></i></u></h2>
<h2 style="text-align: left;">
<u><i>Spherical Symmetry</i></u> :-</h2>
<div>
Spherical symmetry is also called Homaxial apolar symmetry. Spherically symmetrical forms are best suited for floating and rolling. The rare type of symmetry is spherical symmetry. Spherical symmetry is found in Heliozoans and radiolarians. Body of the spherically symmetrical animal can be cut into two identical halves in any one of the infinite number of planes that pass through the central point. Body parts are arranged concentrically around or radiating from a central point in spherical symmetry.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Radial Symmetry</u></i> :- </h2>
<div>
Radial symmetry is also called monaxial heteropolar symmetry. In radial symmetry the sensory and feeding structures are uniformly distributed around the body hence they can interact with their environment equally in all the directions. In radially symmetrical animals body is cylindrical (ex- Hydra), or vase- like ( sponges) or umbrella shaped (ex- Jelly fish). In Radially symmetrical animals the principal axis is oral-aboral axis it is heteropolar. Anterior, posterior ends and dorsal, ventral, lateral surfaces are not differentiated in radially symmetrical forms as well as spherically symmetrical forms. Radial symmetry is found in some sponges and most of the Cniderians. Echinoderms are primarily bilateral animals (their larvae are bilateral). Most of the echinoderms have secondarily become radial, exhibiting pentamerous radial symmetry in the adult stage.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Biradial Symmetry </u></i>:- </h2>
<div>
The Biradial type of symmetry of sea anemone seems to have been derived from the radial type, which is primarily by the elongation of the mouth and associated parts. Biradial symmetry has two planes of symmetry. Ctenophores and most anthozoans exhibit biradial symmetry. In ctenophores most of the body parts radially arranged but the tentacles are paired. A sea anemone, with two siphonoglyphs does exhibit biradial symmetry. While a sea anemone with one siphonoglyph exhibit radial symmetry.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Bilateral Symmetry</u></i> :- </h2>
<div>
In Bilateral symmetry the principal axis is the anterior- posterior axis, it is heteropolar, with differentiate anterior and posterior ends. In Bilateral symmetry sagittal axis is heteropolar and the transverse axis is apolar. In bilatearl symmetry there is only one planes of symmetry, it is median sagittal plane. The appearance of bilateral symmetry was a major advancement in animal evolution. Cephalization is associated with bilateral symmetry. As a result of cephalization, bilaterally symmetrical animals can sense the new environment into which they enter and respond to it more efficiently than other animals. All the tiploblastic animals of animal kingdom exhibit bilateral symmetry.</div>
<div>
<br /></div>
<h3 style="text-align: left;">
<b><i><u>Evolutionary advantages of Bilateral Symmetry</u></i></b> :- </h3>
<div style="text-align: left;">
<ul style="text-align: left;">
<li>Here parts of bodies can develop differently; different organs can be located in different body parts.</li>
<li>Here the movement made more efficient (direction of movement better defined, resistance to water or sediments reduced).</li>
<li>It brings higher mobility as higher flexibility becomes a key factor for more efficient in seeking food, finding mate, avoiding and escaping predators.</li>
</ul>
</div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com1tag:blogger.com,1999:blog-2703452670950399845.post-85680301128101535322013-04-09T00:56:00.000+05:302013-06-13T12:42:27.588+05:30Introduction of Symmetry<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><br /></u></i></h2>
<h2 style="text-align: left;">
<i><u>Animal Organization</u></i> :-</h2>
<div>
The evolution of tissues is the first key transition in the animal body plan. Eumetazoans exhibit higher levels of organization. The embryonic tissue layers of eumetazoans are called germ layers.</div>
<div>
The lowest level of organization is cellular grade of organization, which is exhibited by sponges.</div>
<div>
Division of labor seen among the cells in sponges and such cells have little tendency to become into tissues. Nerve cells and sensory cell are absent; hence cells are functionally isolated in sponges. In cellular grade of organization cells demonstrate division of labor but are not strongly associated to perform a specific collective function.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Diploblastic animals such as cniderians exhibit tissue grade of organization or diploblastic organization. In tissue grade of organization germs layers such as ectoderm and endoderm are developed. Cells are aggregated inti tissues. Nerve cells and sensory cells are present in the epidermis and the gastrodermis. Ectoderm gives rise to the epidermis; endoderm gives rise to the gastrodermis. The cells of a tissue together perform their common functions as a highly coordinates unit. Tiploblastic animals exhibit organ system grade of organization or tiploblastic organization. In organ-system grade of organization all the three germ layers are present such as ectoderm, endoderm and mesoderm. The evolution of mesoderm resulted in structural complexity. The tissues are assembled into larger functional units called organs. Organs working together to perform one or more specific functions constitute an organ system. Eleven kinds of organ systems are observed in metazoans such as integumentary, skeletal, muscular, digestive, respiratory, circulatory, excretory, nervous, endocrine, immune and reproductive. Tiploblastic animals have highly specialized sensory cells and nerve cells which bring about a higher level of coordination and integration.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Symmetry </u></i>:-</h2>
<div>
The symmetry of an animal generally fits its life-style. Radial symmetry is an advantage to sessile or planktomic or slow moving organisms. Evolution of bilateral symmetry is the second key transition in the animal body plan. In symmetrical animals are body lacks definite form or geometrical arrangement of parts and can not divided into mirror image halves by any plane. Gastropods are primarily bilaterally symmetrical and secondary asymmetrical. Most of the sponges and some protozoan like Amoeba exhibit asymmetry. In a symmetrical animal similar body parts occur on the opposite sides of a plane passing through the principle axis of the animal. A symmetrical animal can be cut into two mirror image halves or antimeres by one or more planes of symmetry passing along the principle axis. The term axis refers to an imaginary straight line joining two opposite points at the ends, or on the surfaces of the body. The term principle axis means an imaginary straight line joining the midpoint at one end or surface and the midpoint at the opposite end or surface. The term plane means a flat area that runs through any axis. Bilaterally symmetrical animals possess anterior (cephalic) end posterior (caudal) end dorsal surface, ventral surface and lateral surfaces. Frontral plane is the plane that runs through the anterior- posterior and sagittal axis. Transverse plane(cross section) passes through sagittal and transverse axis. Frontral plane divides a bilaterally symmetrical body into dorsal and ventral portions. Sagittal plane divides bilaterally symmetrical animal into right and left halves. Transverse plane divides the animal into anterior and posterior portions. Each of these three planes is at right angles to the other two planes.</div>
<div>
<br /></div>
<div>
<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxoy9ULyuox5KHDx-7Yg9EnNVOsVKW7bmDuXayHrF9z3SleVnB8Pxlv56XwjoC6uluYFxJ4UT3lCLrrVpX0x_MQbEvkmXiH6nr6KZSbQM-WNo-UQft_QZz3snpAh8_tKcV8bYexhMTrMQ/s1600/Symmetry2.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxoy9ULyuox5KHDx-7Yg9EnNVOsVKW7bmDuXayHrF9z3SleVnB8Pxlv56XwjoC6uluYFxJ4UT3lCLrrVpX0x_MQbEvkmXiH6nr6KZSbQM-WNo-UQft_QZz3snpAh8_tKcV8bYexhMTrMQ/s200/Symmetry2.jpe" width="137" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Example of symmetry </td></tr>
</tbody></table>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgl91-QiXkhu4vKRhvY_N1rh1-IMBtE8HXVnYCODbncBlZU1pUeSSPimVFmZyDePN8sYDShdxR2MgGLidGrAM-YZMxzOpsXXszlSaNvEnLC6PCcf6RgZGfb3UtWybQoIUaWIV8SN31ozt0/s1600/Symmetry3.jpe" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="149" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgl91-QiXkhu4vKRhvY_N1rh1-IMBtE8HXVnYCODbncBlZU1pUeSSPimVFmZyDePN8sYDShdxR2MgGLidGrAM-YZMxzOpsXXszlSaNvEnLC6PCcf6RgZGfb3UtWybQoIUaWIV8SN31ozt0/s200/Symmetry3.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Example of symmetry</td></tr>
</tbody></table>
<div class="separator" style="clear: both; text-align: center;">
</div>
<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5AwnYxfCmH4iwyTGg92p8GC368nJT-7WbIaDNXywA9g8CPKCLCcnR0wvIbs82S06gt4-gCSVPTf4Yr_eIGzBl4RVsdRInsKKyAf88499qoERiDdaEh3_yxma56c5VFgKTd5V8SQavaYs/s1600/Symmetry4.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5AwnYxfCmH4iwyTGg92p8GC368nJT-7WbIaDNXywA9g8CPKCLCcnR0wvIbs82S06gt4-gCSVPTf4Yr_eIGzBl4RVsdRInsKKyAf88499qoERiDdaEh3_yxma56c5VFgKTd5V8SQavaYs/s200/Symmetry4.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Example of symmetry</td></tr>
</tbody></table>
</div>
<div>
<br /></div>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbFVTtjL6X6DV3nG716f7AI6qBQhPPBEgcOqx81wy8OFnvEdsQGVHaxXPyJe9AcNLeUTkvgXK-hBQPF6ruhTTlz3OVHNYvYrORi22VbBUslQn9sQFx3dZ84x8EqBD90z_GO3svxojJn1w/s1600/Symmetry5.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="150" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbFVTtjL6X6DV3nG716f7AI6qBQhPPBEgcOqx81wy8OFnvEdsQGVHaxXPyJe9AcNLeUTkvgXK-hBQPF6ruhTTlz3OVHNYvYrORi22VbBUslQn9sQFx3dZ84x8EqBD90z_GO3svxojJn1w/s200/Symmetry5.jpg" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Example of symmetry</td></tr>
</tbody></table>
<br /></div>
<div>
</div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-12670458612069483542013-04-07T02:20:00.000+05:302013-06-13T12:42:56.640+05:30Types of Canal System of Porifera<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
</h2>
<h2 style="text-align: left;">
(3) <i><u>Rhagon Type </u></i>:- </h2>
<div>
This type of canal system is found in Rhagon which is the larval form of Spongilla. The Rhagon is conical in shape. It is broad at the base and pointed at the apex. Here the radial canal is in the form of rounded chambers called Flagellated Chambers. The flagellated chambers open to the outside by dermal ostia or Prosopyles and they open into the spongocoel by opening called apopyles. The spongocoel opens to the outside by the osculam. The water current takes the following route.</div>
<div>
<br /></div>
<div>
Dermal Ostia → Prosopyle → Flagellated Chamber → Apopyles → Spongocoel → Osculam.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
(4) <i><u>Leucon Type</u></i> :- </h2>
<div>
The Leucon type of canal system is derived from the Rhagon type. The Leucon type has following advanced characters.</div>
<div>
<br /></div>
<div>
(i) The dermal Ostia open into subdermal spaces.</div>
<div>
<br /></div>
<div>
(ii) The subdermal space open into Incurrent canals.</div>
<div>
<br /></div>
<div>
(iii) The incurrent canals open into Flagellated Chambers.</div>
<div>
<br /></div>
<div>
(iv) Choanocytes are located only in flagellated chambers.</div>
<div>
<br /></div>
<div>
(v) The flagellated chamber leads into excurrent canals.</div>
<div>
<br /></div>
<div>
(vi) The excurrent canals open into Spongocoel.</div>
<div>
<br /></div>
<div>
(vii) The Spongocoel opens to the outside by an Osculam.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
There are three kinds of Leucon type of canal system followings-</div>
<div>
<br /></div>
<div>
(a) Euryphylous Type (b) Aphodal Type (c) Diphodal</div>
<div>
<br /></div>
<h3 style="text-align: left;">
(a)<u><i> Euryphylous Type</i></u> :- </h3>
<div>
This type of canal system is exhibited by Telilla, Plakortis etc. This type has the following features :-</div>
<div>
<br /></div>
<div>
(i) The incurrent canal opens into the flagellated chambers by openings called Prosopyles.</div>
<div>
<br /></div>
<div>
(ii) The flagellated chambers are arranged in dusture.</div>
<div>
<br /></div>
<div>
(iii) The flagellated chambers open into the excurrent canal by openings called Apopyles.</div>
<div>
<br /></div>
<div>
(iv) The current of water takes the following route :</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Dermal Pores → Subdermal Spaces → Incurrent Canal → Prosopyles → Flagellated Chamber → Apopyles → Excurrent Canal → Spongocoel → Osculam</div>
<div>
<br />
<br /></div>
<h3 style="text-align: left;">
(b) <i><u>Aphodal Type</u></i><span style="font-weight: normal;"> :-</span></h3>
<div>
<span style="font-weight: normal;">The aphodal type of canal system is seen in Geodia and Stelleta. It has the following salient features :-</span></div>
<div>
<span style="font-weight: normal;"><br /></span></div>
<div>
<span style="font-weight: normal;">(i) The flagellated Chamber opens into excurrent canal through a canal called Aphodus.</span></div>
<div>
<span style="font-weight: normal;"><br /></span></div>
<div>
<span style="font-weight: normal;">(ii) The water current takes the following route :</span></div>
<div>
<span style="font-weight: normal;"><br /></span></div>
<div>
<span style="font-weight: normal;"><br /></span></div>
<div>
<span style="font-weight: normal;">Dermal Ostia </span>→ Subdermal Spaces → Incurrent Canal → Prosopyles → Flagellated Chamber → Aphodus → Excurrent Canal → Spongocoel Osculam.<br />
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(c) <i><u>Diphodal</u></i> :- </h3>
<div>
This type of canal system is seen in Spongilla, Oscarella etc. In this type the incurrent canal opens into the flagellated chamber through a canal called Prosodus. The water current flows through the following route :-</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Dermal Ostia → Subdermal Spaces → Incurrent Canal → Prosopyles → Flagellated Chamber → Aphodus → Excurrent Canal → Spongocoel → Osculam</div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Function of Canal System</u></i> :-</h2>
<div>
The canal system creates a water current to flow in & out of the Sponges continuously. This water current has the following functions :-</div>
<h4 style="text-align: left;">
(a) <i><u>Respiration </u></i>:- </h4>
<div>
The cells absorb O2 from the water current & gives out CO2.</div>
<h4 style="text-align: left;">
(b) <i><u>Nutrition</u></i> :-</h4>
<div>
The water current brings in food particles.</div>
<h4 style="text-align: left;">
(c) <i><u>Excretion</u></i> :- </h4>
<div>
Nitrogenous waste products & faeces are washed out by the water current.</div>
<h4 style="text-align: left;">
(d) <i><u>Reproduction</u></i> :- </h4>
<div>
The water current carries the sperms from one sponge to another sponge.</div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-34856761402971992302013-04-07T01:36:00.000+05:302013-06-13T12:44:43.898+05:30Types of Canal System of Porifera<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
The body of the sponge is traversed by numerous canals opening to the outside by many minute pores. These canals and pores of Sponge constitute the canal system.<br />
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
<i><u>Types of Canal system</u></i> :- </h4>
<div>
<br /></div>
<div>
There are four types of Canal system in Sponges. They are as follows-</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(1) <i><u> Ascon Type</u></i> :- </h2>
<div>
<br /></div>
<div>
<br /></div>
<div>
It is the simplest type of Canal system. It is exhibited by sponges like <u>Olynthus</u> and <u>Leucosolenia</u>. These animals are cylindrical in shape. The body wall is formed of three layers, namely an outer ectoderm, a middle <u>merenchyme</u> & an inner <u>choanocytes</u>. The wall contains many pores called Ostia. These pores are intra-cellular because each pore is formed by the perforation of a single cell called <u>Porocyte</u>. All the ostia open into a central cavity called Spongocoel which is outside at the free end & by a large circular opening called <u>Osculam</u>. The beating of the flagella of the choanocytes creates a water current. The water flows in the following route.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Ostia → Spongocoel → Osculam</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(2) <i><u>Sycon Type</u></i> :- </h2>
<div>
<br /></div>
<div>
<br /></div>
<div>
The Sycon type of canal system is seen in sopnges like Sycon (Grantia), Sycetla etc. There are two types of sycon type canal system. They are- (a) Sycon type without Cortex (b) Sycon type with Cortex.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(A) <i><u>Sycon Type without Cortex</u></i> :- </h3>
<div>
<br /></div>
<div>
It is found in Sycetla. It is derived from the ascon type by the development of many finger- like, outgrowths on the surface. These finger like outgrowth on the surface. These finger like outgrowths are called Canals. These canals are lined with Choanocytes. But the spongocoel is lined with ectoderm. Between the radial canals there is another canal called incurrent canal. The incurrent canalsopen into the radial by minute pores canal Prosopyles. The radial canals open into spongocoel opening called apophles. The spongocoel opens outside by the Osculam. The water flows through the following route-</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Incurrent canal →Prosopyle → Radial canal → Apopyle → Spongocoel → Osculam</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(B) <i><u>Sycon Type with Cortex</u></i> :- </h3>
<div>
<br /></div>
<div>
This type is found in Sycon or Grantia. In addition to the previous type it has four additional features. They are as follows-</div>
<div>
<br /></div>
<div>
(i) The epidermis and Mesenchyme spread over the outer surface so as to form a cortex.</div>
<div>
<br /></div>
<div>
(ii) The free end of incurrent canals open to the outside by minute pores called dermal ostia.</div>
<div>
<br /></div>
<div>
(iii) The incurrent canal opens into the radial canal by openings called Prosopyles.</div>
<div>
<br /></div>
<div>
(iv) The radial canal opens into spongocoel by openings called apopyles.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
In this type the water flows through the following route-</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Dermal Ostia → Incurrent Canal → Prosopyle → Radial Canal → Apopyle → Spongocoel → Osculam</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-20435782280148305242013-04-04T03:55:00.001+05:302013-06-05T18:33:04.857+05:30Water Vascular System of Starfish<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<br />
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u>Introduction </u></i>:- </h2>
<div>
<br /></div>
<div>
The water vascular system is a modified part of coelom & consists of a system of sea water filled canals having certain corpuscles. It plays most vital role in the locomotion of the animals & comprises madreporite stone canal, ring canal, radial canal, Tiedman's body, lateral canals & tube feet.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
(1)<i><u> Madriporite</u></i> :-</h2>
<div>
<br /></div>
<div>
The madreporite is a rounded calcareous plate occurring on the aboral surface of the central disc in inter-radial position. Its surface bears a number of radiating, narrow, straight or wavy grooves or furrows. Each furrow contains many minute pores at its bottom. Each pore leads into a very short, fine, tubular pore-canal. Which passes inward in the substance of the madreporite. There may be about 200 pores and pore-canal. The pore-canals unite to form the collecting canals. Which open into an ampulla beneath the madreporite.</div>
<div>
<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMDK_-gXPV_p_VlhCZ3uqOa7MNQ-rMZN1LGl1XcKDpKqLOgYNzfJ6dC-PPNN0PM54gkfcNeoYFA2YvaXhqJyqhCY21evBh6of5wMaZed78qEPKDe5NOwbcW0y02yppqH9aH_5Ri3N9D5s/s1600/watervascular.gif" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="260" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMDK_-gXPV_p_VlhCZ3uqOa7MNQ-rMZN1LGl1XcKDpKqLOgYNzfJ6dC-PPNN0PM54gkfcNeoYFA2YvaXhqJyqhCY21evBh6of5wMaZed78qEPKDe5NOwbcW0y02yppqH9aH_5Ri3N9D5s/s320/watervascular.gif" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig : Water vascular system of Starfish</td></tr>
</tbody></table>
<br />
<br /></div>
<h2 style="text-align: left;">
(2) <i><u>Stone Canal</u></i> :- </h2>
<div>
<br /></div>
<div>
<br /></div>
<div>
The ampulla opens into a "S" shaped stone canal. The stone canal extends downwards (orally) and opens into a ring canal, around the mouth. The walls of stone canal are supported by a series of calcareous ringd. The lumen of stone canal is lined by very tall flagellated cells. in embryonic stages and young Asterias, the stone canal remains a simple tube but in adult Asterias, lumen of stone canal possesses a prominent ridge with two spirally rolled lamellae.<br />
<br />
<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDoFnmElTnljE0P6DqRGx6oVzPGG0lw1lxESHGon92GFJ_I6_7eIuULqhDIywLvGA_R6nJkAltFc6yMSl_zsduSJXu3gpJtr0Ot06Z8sArre3WZIuSN9-k2VLhOVJ4JcSNhyphenhyphenfjhLPqmSQ/s1600/Diagram+-+Starfish.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDoFnmElTnljE0P6DqRGx6oVzPGG0lw1lxESHGon92GFJ_I6_7eIuULqhDIywLvGA_R6nJkAltFc6yMSl_zsduSJXu3gpJtr0Ot06Z8sArre3WZIuSN9-k2VLhOVJ4JcSNhyphenhyphenfjhLPqmSQ/s400/Diagram+-+Starfish.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig : Diagram of Starfish</td></tr>
</tbody></table>
<br />
<br />
<br />
<br /></div>
<div>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></ </a></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(3) <i><u>Ring Canal</u></i> :- </h2>
<div>
<br /></div>
<div>
The Ring canal or water ring is located to the inner side of the peristomial ring of ossicles and directly above (aboral) to the hyponeural ring sinus. It is wide and pentagonal or five sided.</div>
<div>
<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpJgKUDL9l2CjOC5OLO-Jn0hIkn6WpsQRoExDwaO1aGfhL5uPjYXhshJfxAPraQb32imCqppSmr8j6iYouu4EmahNxHZQgq9QExXE9WwDZ1ApQ2lhbeDadWV8skURmfTqnwmpsnJIAuYg/s1600/starfish.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpJgKUDL9l2CjOC5OLO-Jn0hIkn6WpsQRoExDwaO1aGfhL5uPjYXhshJfxAPraQb32imCqppSmr8j6iYouu4EmahNxHZQgq9QExXE9WwDZ1ApQ2lhbeDadWV8skURmfTqnwmpsnJIAuYg/s400/starfish.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig : Star fish</td></tr>
</tbody></table>
<br /></div>
<h2 style="text-align: left;">
(4) <i><u>Tiedmann's Bodies</u></i> :- </h2>
<div>
<br /></div>
<div>
The ring canal gives out inter radially nine small, yellowish, irregular or rounded glandular bodies called racemose or Tiedmann's bodies from its inner margins. The Tiedmann's body rest upon the peristomial ring of ossicles. The actual function of tiedmann's bodies is still unknown, however they are supposed to be lymphatic glands to manufacture the amoebocytes of the water vascular system.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(5)<i><u> Pollian Vesicles</u></i> :- </h2>
<div>
<br /></div>
<div>
The ring canal gives off on its outer side in the inter radial position one, two or four little, pear shaped, thin walled contractile bladder or reservoirs with long necks called pollian vesicles. They are supposed to regulate pressure inside ambulacral system and to manufacture amoeboid cells of ambulacral system.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
(6) <i><u>Radial Canal</u></i> :- </h2>
<div>
<br /></div>
<div>
From its outer surface the ring canal gives off a radial water canal into each arm that runs throughout the length of the arm and terminates as the lumen of terminal tentacle. In the arm the radial water canal runs immediately to the oral side of the ambulacral muscles.</div>
<div>
<br /></div>
<h2 style="text-align: left;">
(7) <i><u>Lateral Canal </u></i>:-</h2>
<h2 style="text-align: left;">
</h2>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
In each arm, the radial canal gives out two series of short, narrow, transverse branches called lateral or podial canals. Each lateral canal is attached to the base of a tube foot and its provided with a valve to prevent backward flow of fluid into the radial canal.</div>
<div style="text-align: left;">
<br /></div>
<h2>
(8) <i><u>Tube feet</u></i> :- </h2>
<div>
<br /></div>
<div>
As already mentioned, there are four rows of tube feet in each ambulacral groove. A tube foot is a hollow. elastic, thin walled, closed cylinder or sac-like structure having an upper sac like ampulla, a middle tubular podium & a lower disc like sucker. The ampulla lies within the arm, projecting into the coelom above the ambulacral pore which is a gap between the adjacent ambulacral ossicles for the passage of the podium. The tube feet are chief locomotory and respiratory organ of Asterias.<br />
<br />
<h2 style="text-align: left;">
<i><u>Function of Water Vascular System</u></i> :- </h2>
</div>
<div>
<br /></div>
<div>
The water vascular system has three main functions. They are as follows-</div>
<div>
<br />
<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNItbymwQUGsinWXISasL15HP9gsr6BYk-zsiF9U9B1qT_R9VDT1l7rwK-_vzepwm-3x5tGfjw_fvQ7R8g2jxc-64vXvevIyukcgLcIjuJRxhWrIQbYhFpKUMlqmsa9OKqXya76b3huJU/s1600/WaterVascularSystem.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="205" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNItbymwQUGsinWXISasL15HP9gsr6BYk-zsiF9U9B1qT_R9VDT1l7rwK-_vzepwm-3x5tGfjw_fvQ7R8g2jxc-64vXvevIyukcgLcIjuJRxhWrIQbYhFpKUMlqmsa9OKqXya76b3huJU/s400/WaterVascularSystem.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig : Function of water vascular system of Star fish</td></tr>
</tbody></table>
<br /></div>
<h3 style="text-align: left;">
(1) <i><u>Locomotion</u></i> :- </h3>
<div>
<br /></div>
<div>
The water vascular system is used mainly for locomotion. The inner wall of the water vascular canals are provided with cilia. The beating of the cilia causes the seawater to enter through the madreporite. Finally, the seawater reaches the tube feet and their ampullae.</div>
<div>
<br /></div>
<div>
The ampullae contract ; the valves at the junction of the lateral canals and tube feet, prevent the flow of water into radial canals.</div>
<div>
<br /></div>
<div>
The water is forced into the podia. The podia are elongated and protected out through the ambulacral groove. Then the suckers are applied to the substratum.</div>
<div>
<br /></div>
<div>
The tube feet now contract & push the body forward. The water from the tube feet is pushed into the ampulla. Hence, the tube feet shorten. The suckers are released. Then the ampulla contracts & the whole process is repeated.</div>
<div>
<br /></div>
<h3 style="text-align: left;">
(2) <i><u>Food Capture</u></i> :- </h3>
<div>
<br /></div>
<div>
The tube feet are used to capture the prey. The suckers are used to open the shells of molluscas.</div>
<div>
<br /></div>
<h3 style="text-align: left;">
(3) <i><u>Attachment</u></i> :- </h3>
<div>
<br /></div>
<div>
The Starfish can be attached to the rocks by the tube feet.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a><br />
<br />
<br /></div>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
</div>
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script></div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com187tag:blogger.com,1999:blog-2703452670950399845.post-23535682884433491472013-03-30T01:36:00.000+05:302023-03-15T11:55:35.438+05:30Modification of Polyp & Medusa<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><br /></u></i></h2>
<h2 style="text-align: left;">
<i><u>Modification of Polyp</u></i> :-</h2>
<div>
<br /></div>
<h3 style="text-align: left;">
(1) <i><u>Gastro zooids/ Tropho zooids/ Nutritive zooids</u></i> :- </h3>
<div>
<br /></div>
<div>
(i) Cylindrical with large mouth and a tentacles.</div>
<div>
<br /></div>
<div>
(ii) Tentecles bear lateral branches the tenilla with nematocyst.</div>
<div>
<br /></div>
<div>
(iii) A well formed mouth & gastro vascular cavity.</div>
<div>
<br /></div>
<div>
(iv) Function - food ingestion.</div>
<div>
<br /></div>
<div>
(v) Variation - No tentacles in gastro zooids of velella.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Gastro zooids exists in the following modified forms.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(A) <i><u>Siphon</u></i> :- </h4>
<div>
<br /></div>
<div>
(i) It is a polyp form, but without normal tentacles.</div>
<div>
<br /></div>
<div>
(ii) A single large hollow, highly contractile tentacle hang from or near the base.</div>
<div>
<br /></div>
<div>
(iii) Lateral contractile branches of tentacles are called tenilla, which terminates in a large & complicated know of nematocysts.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(B) <i><u>Siphono zooids</u></i> :-</h4>
<div>
<br /></div>
<div>
(i) Gastro zooids is modified to produce a current producing device at the expense of other structure.</div>
<div>
<br /></div>
<div>
(ii) They are devoid of tentacles, longitudinal muscles but may sometimes possess septal filaments.</div>
<div>
<br /></div>
<div>
(iii) The siphonoglyphs are strongly developed.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Examples</i></b> :- Pentularia; Renilla;</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(2) <i><u>Dactylo zooids/Macro zooids</u></i> :-</h3>
<div>
<br /></div>
<div>
<br /></div>
<div>
(i) Protective zooids are actually derived from the gastro zooids by the reduction or total loss of mouth.</div>
<div>
<br /></div>
<div>
(ii) They are elongated & highly extensible.</div>
<div>
<br /></div>
<div>
(iii) Long basal unbranched tentacle arising from the base of the polyp and without nematocysts.</div>
<div>
<br /></div>
<div>
(iv) Funtion - Tactila & projection of colony.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
The Dactylozooids exhibit following structure variations-</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(A) <i><u>Tentaculo zooids</u></i> :- </h4>
<div>
<br /></div>
<div>
(i) Dactylozooids assumes a long tentacle like appearance.</div>
<div>
<br /></div>
<div>
(ii) They may be definity arranged in relation to the gastrozooids & are usually situated at the margin.</div>
<div>
<br /></div>
<div>
(iii) Function - Sensory in function.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Example</i></b> :- Hydroctena;</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(B) <i><u>Spiral zooids</u></i> :- </h4>
<div>
<br /></div>
<div>
In Hydroctena the spiral zooids with capitate tentacles remain scattered through out the colony.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(C) <i><u>Sarcostyles / Nematophore</u></i> :- </h4>
<div>
<br /></div>
<div>
(i) Sarcostyles spring from tiny theca located on stems and on the hydrothecae of gastro zooids.</div>
<div>
<br /></div>
<div>
(ii) The nematophores are usually with capitate ends, beset with nematocysts or adhesive cells or both.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Example</i></b> :- Plumularidae;</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(D) <i><u>Palpons</u></i> :-</h4>
<div>
<br /></div>
<div>
(i) Simple hollow tentacle like bodies which spring from the margin of the body.</div>
<div>
<br /></div>
<div>
(ii) Palpons in velella & Porpita act as the Dactylo zooids.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(E) <i><u>Cyston</u></i> :- </h4>
<div>
<br /></div>
<div>
(i) In Siphonophora, a distal pore present in the dactylo zooids is called the cyston.</div>
<div>
<br /></div>
<div>
(ii) Function - Excretory in function.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3>
(3) <i><u>Gonozooids / Blastostyles </u></i>:-</h3>
<div>
<br /></div>
<div>
<br /></div>
<div>
(i) Club shaped bodies devoid of mouth & tentacles.</div>
<div>
<br /></div>
<div>
(ii) The coelenteron is greatly reduced.</div>
<div>
<br /></div>
<div>
(iii) Modified polyps that produce medusoid forms or their morphological equivalent by budding.</div>
<div>
<br /></div>
<div>
(iv) Function - These zooids are the reproductive individual of the colony.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
The Gonozooids exhibit following structure variations-</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(A) <i><u>Gonosiphon</u></i> :- </h4>
<div>
<br /></div>
<div>
(i) Gonozooids may resemble gastrozooids & may even possess a mouth.</div>
<div>
<br /></div>
<div>
(ii) The tentacles are absent.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Examples</i></b> :- Velella; Porpita;</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(B) <i><u>Gonodendron </u></i>:-</h4>
<div>
<br /></div>
<div>
(i) Gonodendrons are present as brancheol stalks which bear grape like clusteres of gonophores & are usually provided with a long retractile gonopalpon.</div>
<div>
<br /></div>
<div>
(ii) Found in Siphonophora.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(C) <i><u>Gonopalpon</u></i> :-</h4>
<div>
<br /></div>
<div>
(i) Tentacle like dactylo zooids remains associated with gonophores.</div>
<div>
<br /></div>
<div>
(ii) Found in Siphonophora.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
Special Types of Zooids :- </h3>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(A) <i><u>Gonostyles</u></i> :- </h4>
<div>
<br /></div>
<div>
(i) The mouth & coelenteron are present.</div>
<div>
<br /></div>
<div>
(ii) Gonads remain attached with the Siphono zooids.</div>
<div>
<br /></div>
<div>
(iii) These are secondary siphono zooids. example- Porpita;</div>
<div>
<br /></div>
<div>
(iv) Function - Gonostyles are primarily reproductive in function & may secondarily be nutritive.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(B) <i><u>Hydrorhiza</u></i> :-</h4>
<div>
<br /></div>
<div>
In Obelia hydrorhiza acts as the organ of attachment for the whole colony.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(C) <i><u>Hydrocaulus</u></i> :- </h4>
<div>
<br /></div>
<div>
In Obelia, the hydrocaulus, arising from the hydrorhiza, bears different zooids & helps to convey the food matters to the different parts of the colony.</div>
<div>
<br /></div>
<div>
<br />
<br />
<h2 style="text-align: left;">
<i><u>Modifications of Medusoid Form</u></i> :- </h2>
</div>
<div>
<br />
<br />
<h3>
(1) <i><u>Nectocalyx / Nectophore / Swimming bell</u></i> :- </h3>
</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(i) This form is present in siphonophora excepting physalia. Typically medusoid with bell, vellum, radial canal etc. But lack mouth-manubrium sense organ & tentacles.</div>
<div>
<br /></div>
<div>
(ii) Muscles highly developed.</div>
<div>
<br /></div>
<div>
(iii) Function - Locomotion of colony.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(2)<i><u> Bract / Hydrophyllium / Phylozooids</u></i> :- </h3>
<div>
<br /></div>
<div>
<br /></div>
<div>
(i) Highly modified, thick geletinous leaf like or helmet shaped with simple or branched radial canal.</div>
<div>
<br /></div>
<div>
(ii) Function - Protection of the colony.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(3) <i><u>Pneumatophore / Float</u></i> :- </h3>
<div>
<br />
<br />
(i) This type is present in siphonophora excepting Diphyes.<br />
<br />
(ii) Medusoid bell, Muscular exumbrellar wall called Pneumatocodon & glandular subumbrellar wall known as Pneumatosaccus or Air sac with opening.<br />
<br />
(iii) This opening may be closed or reduced to a pore guarded by a sphincter muscle.<br />
<br />
(iv) Gastrovascular cavity divided into chambers. Bottom of the air sac form expanded funnel producing gas called gas gland. In Physalia gas contain 91% Nitrogen, 1.5% Argon & 7.5 % Oxygen.<br />
<br />
(v) Function - Hydrostatic.<br />
<br />
<br />
<h3 style="text-align: left;">
(4) <i><u>Auriophore </u></i>:- </h3>
</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
Function unknown. Ovoid in shape with a minute canal connect to pneumatophore with which it always remain associated. Around canal is a mass of muscles called Pistillum.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(5)<i><u> Gonophores </u></i>:-</h3>
<div>
<br /></div>
<div>
<br /></div>
<div>
These are the medusoid forms which are sexually differentiated.</div>
<div>
<br /></div>
<div>
(i) They may occur singlely or in clustures.</div>
<div>
<br /></div>
<div>
(ii) Most of the colony are hermaphrodite. Gonophores are diocious. They may be medusa like structure having bell, vellum, radial canals & a manubrium, Radial canal bears gonads.</div>
<div>
<br /></div>
<div>
(iii) The gonophores are devoid of mouth, tentacles & sense organs. In some cases the female gonophores appears as medusa like, while the male gonophore sac like. The male gonophore may attached with the colony while the female gonophore die after discharging the sex cells.</div>
<div>
<br /></div>
<div>
(iv) Function - Reproduction.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
</div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com1tag:blogger.com,1999:blog-2703452670950399845.post-13536326599266090022013-03-26T17:16:00.001+05:302013-06-13T12:46:02.746+05:30Description & Types of Echinoderm Larva<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><br /></u></i></h2>
<h2 style="text-align: left;">
<i><u>Description</u></i> :-</h2>
<div>
<br /></div>
<div>
In Echinoderms the development may be direct or indirect. In direct development is no larva. Direct development is seem in only a few echinoderm living in Arctic & Antarctic waters. In indirect development the life cycle includes one or more larvae. Many types of larvae occur in echinoderms. They are the following-</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(1) <i><u>Dipleurula Larva</u></i> :-</h2>
<div>
<br /></div>
<div>
This larva develops from gastrula. It has the following salient features-</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(a) Dipleurula is the fundamental larva of all echinoderms.</div>
<div>
<br /></div>
<div>
(b) It is microscopic.</div>
<div>
<br /></div>
<div>
(c) It is a free swimming larva.</div>
<div>
<br /></div>
<div>
(d) It is bilaterally symmetrical and oval in shape.</div>
<div>
<br /></div>
<div>
(e) It has a gut formed of the mouth, the oesophagus, the intestine, the stomach & the anus.</div>
<div>
<br /></div>
<div>
(f) It gas two ciliary bands, viz a pre-oral band around the mouth and an adoral band inside.</div>
<div>
<br /></div>
<div>
(g) The pre-oral band is used for locomotion & adoral band is used for the collection of food.</div>
<div>
<br /></div>
<div>
(h) It feed on diatoms.</div>
<div>
<br /></div>
<div>
(i) The dipleurula develops into Bipinnaria larva.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(2) <i><u>Bipinnaria Larva</u></i> :- </h2>
<div>
<br /></div>
<div>
It is the second larva of Starfish. It develops from dipleurula larva. It has the following salient features-</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(a) It is minute, microscopic and swims freely on the water surface.</div>
<div>
<br /></div>
<div>
(b) It is bilaterally symmetrical and has alimentary canal with a mouth of the anterior end and an anus at the posterior end.</div>
<div>
<br /></div>
<div>
(c) The body has a number of outgrowths called arms. The arms are covered by ciliated bands and are used for locomotion. It has two unpaired arms and five pairs of paired arms. They are-</div>
<div>
<br /></div>
<div>
(i) Median dorsal arms</div>
<div>
(ii) Median ventral arms</div>
<div>
(iii) Pre-oral arms</div>
<div>
(iv) Post-oral arms</div>
<div>
(v) Antero dorsal arms</div>
<div>
(vi) Postero dorsal arms</div>
<div>
(vii) Postero lateral arms</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(3) <i><u>Brachiolaria Larva</u></i> :- </h2>
<div>
<br /></div>
<div>
It is the third larva of after a short free swimming life. The Bipinnaria larva. the Brachiolaria larva. The pre-oral region of this larva has three processes called Brachiolar arms. These three arms are tipped with suckers. It swims and feed like a Bipinnaria.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(4) <i><u>Ophiopluteus</u></i> :- </h2>
<div>
<br /></div>
<div>
(a) It is the larva of Ophiuroidea.</div>
<div>
<br /></div>
<div>
(b) The pre- oral lobe is small.</div>
<div>
<br /></div>
<div>
(c) The ciliated band is single.</div>
<div>
<br /></div>
<div>
(d) The arms are supported by Calcareous rods.</div>
<div>
<br /></div>
<div>
(e) The larva has a pair of pre-oral arms, a pair of post oral arms, a pair of postero dorsal arms and a pair of postero lateral arms.</div>
<div>
<br /></div>
<div>
(f) The postero lateral arms are always longer and directed forward, so that the larva appears like a "V" shaped.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(5) <i><u>Echinopluteus</u></i> :-</h2>
<div>
<br /></div>
<div>
(a) It is the larva of Echinoidea.</div>
<div>
<br /></div>
<div>
(b) It has small pre-oral lobe & a single ciliary band,</div>
<div>
<br /></div>
<div>
(c) The arms are supported by calcareous rods.</div>
<div>
<br /></div>
<div>
(d) The larva is provided with a pair of pre-oral arms, a pair of post-oral arms, a pair of antero lateral arms, a pair of antero dorsal arms & a median posterior arm.</div>
<div>
<br /></div>
<div>
(e) The postero lateral arms are very short & directed backwards.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(6) <i><u>Auricularia</u></i> :- </h2>
<div>
<br /></div>
<div>
(a) It is the larval form of Holothuroidea.</div>
<div>
<br /></div>
<div>
(b) There is a well developed pre-oral lobe.</div>
<div>
<br /></div>
<div>
(c) Arms are supported not by calcareous rods but the calcareous structures are in the form of wheels, spheres, star shaped bodies etc.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(7) <i><u>Doliolaria of holothuroidea (Pupa)</u></i>:- </h2>
<div>
<br /></div>
<div>
(a) In holothuroidea (sea-cucumber) the auricularia larva develops into doliolaria larva.</div>
<div>
<br /></div>
<div>
(b) The larva is also called a pupa.</div>
<div>
<br /></div>
<div>
(c) It is free swimming larva.</div>
<div>
<br /></div>
<div>
(d) It is barrel shaped.</div>
<div>
<br /></div>
<div>
(e) The calcareous skeleton is in the form a spheres.</div>
<div>
<br /></div>
<div>
(f) The ciliated bands are broken into pieces.</div>
<div>
<br /></div>
<div>
(g) Metamorphosis begins during free swimming life. After metamorphosis, the larva sinks into the bottom to become the adult.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(8) <i><u>Doliolaria of Crinoidea</u></i> :- </h2>
<div>
<br /></div>
<div>
(a) It is the larva of Antedone.</div>
<div>
<br /></div>
<div>
(b) Is is a free-swimming larva.</div>
<div>
<br /></div>
<div>
(c) It is bilaterally symmetrical.</div>
<div>
<br /></div>
<div>
(d) It is barrel shaped.</div>
<div>
<br /></div>
<div>
(e) It has four or five ciliary bands.</div>
<div>
<br /></div>
<div>
(f) At the anterior end the ectoderm thickens to form an apical plate.</div>
<div>
<br /></div>
<div>
(g) The apical plate bears a tuft of cilia called apical sensor tuft.</div>
<div>
<br /></div>
<div>
(h) An adhesive pit is present between the first and second ciliary bands. It is used for attachment.</div>
<div>
<br /></div>
<div>
(i) A mouth is located between the second and third ciliary bands.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(9) <i><u>Pentacrinoid larva</u></i> :- </h2>
<div>
<br /></div>
<div>
(a) It is the second larva of antedone.</div>
<div>
<br /></div>
<div>
(b) It develops from Doliolaria larva.</div>
<div>
<br /></div>
<div>
(c) It looks like a sea-lily.</div>
<div>
<br /></div>
<div>
(d) It has a stalk.</div>
<div>
<br /></div>
<div>
(e) the stalk develops from the pre-oral lobe of Doliolaria.</div>
<div>
<br /></div>
<div>
(f) One end of the stalk is attached to the substratum with the help of a disc and the free ends bears a crown.</div>
<div>
<br /></div>
<div>
(g) The crown consists of a central mouth surrounded by a circle of tentacles.</div>
<div>
<br /></div>
<div>
(h) During metamorphosis the crown develops cirri & breaks off from the stalk as a free living antedone.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Metamorphosis</u></i> :- </h2>
<div>
<br /></div>
<div>
During Metamorphosis the bilaterally symmetrical larvae become transformed into radially symmetrical adults.</div>
<div>
<br /></div>
<div>
In all these larval forms during metamorphosis there is alternation of the position of the mouth.</div>
<div>
In the Crinoidea, the mouth is shifted to the posterior end. But in all other echinoderms mouth is shifted to the left side with the corresponding shifting of the coelomic cavity.</div>
<div>
<br /></div>
<div>
In Crinoidea and Asteroidea the larva becomes fixed to some substratum by the pre-oral lobe at the time of metamorphosis & a fixation disc is formed for this purpose. In the Crinoidea the fixation persists until the adult form is completely formes. But in Asteroidea fixation is temporary.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-70825231307135908722013-03-26T02:06:00.001+05:302013-06-13T12:46:33.645+05:30Importance & Significance of Echinoderm Larva<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u>Importance</u></i> :-</h2>
<div>
<br /></div>
<h3 style="text-align: left;">
(i) <i><u>Echinoderm Larva v/s Origin of Chordate</u></i> :-</h3>
<div>
<br /></div>
<div>
It is an establishment fact that Echinoderm is very near to Chordate. Many Scientists are attempting to prove that the Chordates have been originated from echinoderms. So, the echinoderms Hemichordates, Tumicules and the higher chordates are together placed under a group Deutero stomial, due to secondary development of oral aperture. In this view of similarities some important views are described here-</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(a) <i><u>Similarity about Morphological & Anatomical </u></i>:-</h4>
<div>
<br /></div>
<div>
(i) The bilateral symmetry of Aurecularia of Echinoderm is similar to the Tornaria of Balanoglossus of Hemichordate in respect to their cleavage pattern, looping bonds enterocoelic origin of coelom and body cavity.</div>
<div>
<br /></div>
<div>
(ii) According to Willy, Echinoderms are descended from bilateral symmetrical, pelagic. The general likeness between Auricularia and Tornaria is so great that it can only be accounted for on the ground of genetic affinity.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Remark</i></b> :-</div>
<div>
H.B. Fell (1948) showed that parallalism in development has often take place among the different sub classes of Echinoderms and concluded that the similarity of the free swimming larva of certain Echinoderm and Balanoglossus supplies trust worthy evidence of common ancestry.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(b) <i><u>Similarity between Bipinaria & Tornaria :-( according to Metschnikoff-1869)</u></i></h3>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<div>
(i) Free swimming and bilateral symmetrical larval form in both.</div>
<div>
<br /></div>
<div>
(ii) Transparent with similar ciliated bands.</div>
<div>
<br /></div>
<div>
(iii) Similar location of mouth and anus.</div>
<div>
<br /></div>
<div>
(iv) The madriporic vesicle in Bipinnaria are thought. its homologous with heart vesicle of Balanoglossus.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i><u>Bather's view(1900)</u></i> :-</h3>
<div>
<br /></div>
<div>
Bather said that common ancestry of Hemichordates and Echinoderm from Dipturula.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Taxonomic Affinities</u></i> :-</h2>
<div>
<br /></div>
<div>
<br /></div>
<div>
Closely looking as the it is seen that the larval similarities do not indicate the taxonomic affinities. Among Eleutherozoa, two well developed larval forms occurs-</div>
<div>
<br /></div>
<div>
(a) <u>Pluteus</u> (Ophiroidea & Echinoidea ) with two arms & bilateral symmetry.</div>
<div>
<br /></div>
<div>
(b) <u>Auricularia group</u> (Asteroidea & Holothuroidea) with ciliated bands.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
On the basis of larval taxonomy Ophiroidea should be placed near Echinoidea & Asteroidea near to Holothuroidea. But this is not in common arrangement from the Plaentological & morphological studies.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Significance </u></i>:-</h2>
<div>
<br /></div>
<div>
All the larval of echinoderms have a bilateral symmetry. Hence it is believed that the ancestor of echinoderms was a bilaterally symmetrical animal. According to Bather(1900), this ancestor was called dipleurula. But according to Semon(1988) this ancestor was called Pentaetulla. The pentaetulla ancestor was universally accepted.</div>
<div>
<br /></div>
<div>
The radial symmetry of exhibited by Coelenterate and Porifera is primary. The radial symmetry in Echinoderm is superficial, concealing the true bilateral symmetry.</div>
<div>
<br /></div>
<div>
The adult Echinoderms are more primitive than larvae because they possess the features of lower animals like Porifera and Coelenterala. The primitive characters are radial symmetry, absence of head, lack of anterior and posterior ends. Hence during Metamorphosis the advanced larva becomes a primitive adult. Hence the Metamorphosis is Retrogressive.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com1tag:blogger.com,1999:blog-2703452670950399845.post-15574486995227915532013-03-26T00:45:00.000+05:302013-06-13T12:47:00.165+05:30Echinoderm Larva<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><br /></u></i></h2>
<h2 style="text-align: left;">
<i><u>Introduction</u></i> :-</h2>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
Larva is the sexually immature, pre-adult, free living, stage of development, developing indirectly by metamorphosis. There are so many larval forms in each and every phyla. All these larval forms pay great attention to the zoologist, due to various reasons. Echinoderm Larva, among all reasons.</div>
<div style="text-align: left;">
The main important reason is its bilateral symmetry and another reason is precursor of chordate ancestry. Although echinoderm larva shows bilateral symmetry. However larval morphology and adult morphology has no resemblance. It demanded another or phylo genetic importance.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
<br /></div>
<h3 style="text-align: left;">
<i><u>Brief diary on pre Larval events </u></i>:- </h3>
<div>
<br /></div>
<div>
(i) Echinoderm, the only sole marine invertebrate are uni-sexual. Eggs and sperms fertilized externally and Zygote undergoes holloblastic clevage to produce hollow one larval blastula.</div>
<div>
<br /></div>
<div>
(ii) By invagination, a gastrula is formed with outer ectoderm and inner end mesoderm.</div>
<div>
<br /></div>
<div>
(iii) Mesenchome layer and networks are formed between ectoderm and endoderm.</div>
<div>
<br /></div>
<div>
(iv) By gradual development blastopore develops in the anus and a new opening on ventral side forms larva mouth.</div>
<div>
<br /></div>
<div>
(v) The larval form is the focus of our discussion which gradually modified into adult.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i><u>Basic change of Symmetry from Larva to adult</u></i> :-</h3>
<div>
<br /></div>
<div>
The main astonishing change of the development is the bilateral symmetrical larva changes into radial symmetry of adult.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i><u>Developmental fate of Larval Mouth & Anas</u></i> :- </h3>
<div>
<br /></div>
<div>
(i) In Asteroidea and Echinoidea new mouth and anus are formed in adult, because larval mouth and anus are closed.</div>
<div>
<br /></div>
<div>
(ii) In Holothuroidea larval mouth and anus persist in adult.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
(iii) In Ophiuroidea, larval mouth persists, but anus is lacking in adult.</div>
<div>
<br /></div>
<div>
(iv) In Crinoidea, larval mouth and anus are absent in adult.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Basic Larval Forms </u></i>:- </h2>
<div>
<br /></div>
<div>
There are two basic larval forms in the echinoderm larva. There are Dipleurula larva and Pentactula larva. From these two basic forms various diverse larval forms appears in course of evolution.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(A) <i><u>Dipleurula Larva</u></i> :- </h3>
<div>
<br /></div>
<div>
<br /></div>
<div>
This larva concept was first proposed by Bather (1990). It is regarded by many, as the hypothelical present. The main important features are-</div>
<div>
<br /></div>
<div>
(i) Symmetry - Bilateral</div>
<div>
<br /></div>
<div>
(ii) Shape - Egg shaped</div>
<div>
<br /></div>
<div>
(iii) Ciliated band - A circumoral ciliated band encircles the mouth on ventral side.</div>
<div>
<br /></div>
<div>
(iv) Disposition of Anus - Ventral</div>
<div>
<br /></div>
<div>
(v) Note - The major changes involve in other echinoderm larva are due to differential disposition of ciliated bands.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(B) <i><u>Pentactula Larva</u></i> :- </h3>
<div>
<br /></div>
<div>
This concept is supported by Semon(1888), Burry(1895), Hyman(1955) & many others. They presumed the pentactula larva is the next larval stage of Dipleurula larva. The main features are-</div>
<div>
<br /></div>
<div>
(i) Symmetry - Bilateral</div>
<div>
<br /></div>
<div>
(ii) Shape - Belt shaped</div>
<div>
<br /></div>
<div>
(iii) Tentacles - Five around Mouth</div>
<div>
<br /></div>
<div>
(iv) Hydrocoel - Separated from Coelom</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div style="text-align: left;">
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
</div>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-86700927981617953532013-03-23T22:19:00.003+05:302013-06-13T12:47:31.254+05:30Polymorphism Of Siphonophora<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
The following are the different types of zooids in polymorphic colonies.<br />
<br />
<h2 style="text-align: left;">
(A) <i><u>Medusoid Forms</u></i> :-</h2>
<h3 style="text-align: left;">
</h3>
<h3 style="text-align: left;">
(i) <i><u>Pneumatophore</u></i> :-</h3>
<div>
<br /></div>
<div>
It is medusoid form. It functions as a float. It makes the colony floating on the surface of water. It is situated at the apex of the colony. It is filled with air. It takes different shapes in different animals. it is cup- like in Helistemma, disc-shaped in Porpita & sail like in velella.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(ii) <i><u>Nectocalyces</u></i> :- </h3>
<div>
<br /></div>
<div>
These are medusoid forms. They are bell shaped. The mouth and tentacles are absent from them. The musculature is well developed. They bring about the locomotion of the colony. Hence they are swimming bells.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Example</i></b> :- Helistemma</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(iii) <i><u>Hydrophyllium</u></i> :- </h3>
<div>
<br /></div>
<div>
It is a medusoid form. It is leaf like. It serves to covr and protect the other zooids of the colony.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Example</i></b> :- Helistemma</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(iv) <i><u>Gonophores</u></i> :-</h3>
<div>
<br /></div>
<div>
These are medusoid forms. They contain gonads. These are two types of gonophores, viz male gonophores & female gonophores. The male gonophores contain the testes & the female gonophores contain the ovaris.</div>
<div>
On reaching sexual maturity, they release sperms & ova. After the release of gamets, the gonophores die.</div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
(B) <i><u>Polypoid forms</u></i> :- </h2>
<div>
<br /></div>
<h3 style="text-align: left;">
(v) Gastrozooids :- </h3>
<div>
<br /></div>
<div>
It is a polyp. It nutritive in function. It has a mouth & a large gastrocoel. It gas a long tentacle bearing lateral branches called tentilla. Each tentilla ends in a coil of nematocysts.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Example</i></b> :- Helistemma</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(vi ) Dactylozooid :- </h3>
<div>
<br /></div>
<div>
It is protective in funtion. It looks like a gastrozooid but it has no mouth. A coiled tentacle arises from the base. The tentacle is unbranched. </div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Example</i></b> :- Helistemma</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(vii) <i><u>Gonozooids</u></i> :- </h3>
<div>
<br /></div>
<div>
These are reproductive zooids. They are also called blastostyles. They produce Medusa by budding.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Example </i></b>:- Physalia </div>
<div>
<br /></div>
<div>
<br />
<br /></div>
<div>
<h2 style="text-align: left;">
<i><u>Basic Unit of Polymorphism</u></i> :-</h2>
<h2 style="text-align: left;">
</h2>
<h3 style="text-align: left;">
(1) <i><u>Polyp</u></i> :- </h3>
</div>
<div>
<br /></div>
<h4 style="text-align: left;">
(A) <i><u>Gastrozooids</u></i> :-</h4>
<div>
<br /></div>
<div>
(a) Siphon ( Siphonophora)</div>
<div>
<br /></div>
<div>
(b) Siphono zooids (Renilla)</div>
<div>
<br /></div>
<div>
(c) Gastrozooids of Millipora </div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(B) Dactylozooids :- </h4>
<div>
<br /></div>
<div>
(a) Tentaculo zooids (Hydractena)</div>
<div>
<br /></div>
<div>
(b) Spiral zooids (Hydractena)</div>
<div>
<br /></div>
<div>
(c) Sarcostyle (Plumularridae)</div>
<div>
<br /></div>
<div>
(d) Paplons ( Porpita/ Vellela )</div>
<div>
<br /></div>
<div>
(e) Syston (Siphonophora)</div>
<div>
<br /></div>
<div>
(f) Dactylozooids of millipora</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
(c) <i><u>Gonozooids</u></i> :-</h4>
<div>
<br /></div>
<div>
(a) Gonosiphon (Vellela/ Porpita)</div>
<div>
<br /></div>
<div>
(b) Gonodendron ( Siphonophora)</div>
<div>
<br /></div>
<div>
(c) Gonopalpon (Siphonophora)</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(2) <i><u>Medusa</u></i> :-</h3>
<div>
<br /></div>
<div>
(a) Nectocalyx</div>
<div>
<br /></div>
<div>
(b) Pneumatophores (Siphonophore)</div>
<div>
<br /></div>
<div>
(c) Aurophores (Siphonophore)</div>
<div>
<br /></div>
<div>
(d) Bracts (Siphonophore)</div>
<div>
<br /></div>
<div>
(e) Gonophores (Siphonophore)</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i><u>Special Types of Zooids</u></i> :- </h3>
<div>
<br /></div>
<div>
(a) Gonostyles (Porpita)</div>
<div>
<br /></div>
<div>
(b) Hydrorhiza (Obelia)</div>
<div>
<br /></div>
<div>
(c) Hydrocaulus (Obelia)</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-80752693702469920582013-03-23T21:45:00.001+05:302013-06-13T12:48:05.947+05:30Polymorphism of Cnideria<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u>Introduction</u></i> :- </h2>
<div>
<br /></div>
<div>
Polymorphism is a phenomenon of existance of different physiological and morphological forms represented by an extensive range of variations.<br />
To define in other way, polymorphism means the existance of individuals(zooids) of a single species in more than one forms and functions.<br />
<br />
<br />
<h2 style="text-align: left;">
<i><u>Theories of Polymorphism</u></i> :- </h2>
</div>
<div>
<br /></div>
<div>
Various theories have been put forward to explain the phenomenon of polymorphism, of these the important theories are-</div>
<div>
<br /></div>
<h3 style="text-align: left;">
(i) <i><u>Poly Organ Theory</u></i> :- </h3>
<div>
<br /></div>
<div>
Huxley & other suggested that each polymorphic is an individual member, of which polyp & medusa budded of as organ.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(ii) <i><u>PolyPesson Theory</u></i> :- </h3>
<div>
<br /></div>
<div>
This theory suggest that the cniderian colony is made up of independent & separate individuals which remain inorganic connections, with one another. This theory hold that zooids are separate individuals.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(iii) <i><u>Medusa Theory</u></i> :- </h3>
<div>
<br /></div>
<div>
This theory advocates that primitive zooids of the polymorphic colony was a Medusa which produce other Medusa by budding. Medusa possess locomotary and reproductive power. This theory holds that different organs of the colony are nothing but to time from their attachment.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(iv) <i><u>Neoteny Theory</u></i> :- </h3>
<div>
<br /></div>
<div>
Polymorphic colony arrows by neoteny and having the power of reproduction in larval conditions and there by specialization of zooids takes place.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2 style="text-align: left;">
<i><u>Significance of Polymorphism</u></i> :-</h2>
<h2 style="text-align: left;">
</h2>
<div>
(i) Division of labour (function) due to lack of organs and low level of organization. Polyp zooids are concerned with food capture, feeding, nutrition, respiration, excretion, asexual reproduction etc.</div>
<div>
and medusoid zooids are involved with sexual reproduction, protection, floating etc.</div>
<div>
<br /></div>
<div>
(ii) For more security, food gathering & distribution of individual.</div>
<div>
<br /></div>
<div>
(iii) Due to metagenesis i,e alternation of sexual & asexual stages of life cycle enhance the survival & rejuvenation of genetic materials.</div>
<div>
<br /></div>
<div>
Polymorphism is the most characteristic feature of colonial Cniderians. Entire polymorphic diversities present in a species of colonial cniderians can be reduced into two zooids the polyp & medusa, which remain in organic connection with one another.</div>
<div>
<br /></div>
<div>
In the class Hydrozoa polypoid & medusoid forms is predominant while in class Actinozoa, zooids are exclusively polypoid. Extreme specialization of forms is exhibited by the members of the order Siphonophora of the class Hydrozoa. Their colonies exhibit highest degree of Polymorphism. </div>
<div style="text-align: left;">
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-14798586394784198392013-03-20T17:39:00.001+05:302013-06-13T12:48:59.640+05:30Metamerism in Annelids<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><br /></u></i></h2>
<h2 style="text-align: left;">
<i><u>Definition</u></i> :-</h2>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
Metamerism is a type of body segmentation in bilateral animals(such as Annelids) which involves a longitudinal division of the body into a Linear series of similar section of parts.</div>
<div style="text-align: left;">
Each section or part is called a segment or somile or metamere. In annelids each segment is demarcated externally by an anterior and a posterior groove.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
<br /></div>
<h3 style="text-align: left;">
<i><u>Metamerism in Animal Kingdom</u></i> :- </h3>
<div>
<br /></div>
<div>
(i) Metamerism encountered for the first time in annelids.</div>
<div>
<br /></div>
<div>
(ii) Apart from this it is also found in Arthropode and vertebrate and one group of mollusca (monoplacophora).</div>
<div>
<br /></div>
<div>
(iii) Tape worms show pseudometamerism or strobilization, which is not true metameric segmentation.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i><u>Characteristics of Metamerism</u></i> :-</h3>
<div>
<br /></div>
<div>
(i) Each metamere repeats were some all of the various organ unit.</div>
<div>
<br /></div>
<div>
(ii) The organs of mesodermal origin are so arranged.</div>
<div>
<br /></div>
<div>
(iii) The primary segmental divisions are the body wall musculature and sometimes the coelom.</div>
<div>
<br /></div>
<div>
(iv) This in turn imposed a corresponding metamerism, the nerves, blood vessels, excretory organ etc.</div>
<div>
<br /></div>
<div>
(v) Longitudinal structures such as gut, principle blood vessels and nerves extend the entire length of the body passing the successive segments while other structures such as gonads are repeated in each or few segments.</div>
<div>
<br /></div>
<div>
(vi) Metamerism is always limited to the trunk region. The head or acron represented by prostomium (bearing the brain and sense organs) & the pygidium (bearing the anus ) are not metameres.</div>
<div>
<br /></div>
<div>
(vii) Metameres in annelids are essentially alike & complete externally & internally.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(1) <i><u>Pseudometamerism Theory(Hyrnan,1951 Gardrich)</u></i> :- </h3>
<div>
<br /></div>
<div>
(i) Firstly repetition of body parts-muscle, nerves, nephridia, coelom blood vessels occured.</div>
<div>
<br /></div>
<div>
(ii) Secondly cross partition developed between them and a segmented condition obtained.</div>
<div>
<br /></div>
<div>
(iii) Each segment received a repeated part of each system.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
<i><u>Evidence</u></i> :- </h4>
<div>
<br /></div>
<div>
(i) Serial repetion of organs (testes, yolk glands, transverse nerve connectives ) are seen in elongated turbellarians.</div>
<div>
<br /></div>
<div>
(ii) During the formation of somiles in larval and adult stage of some annelids, cross partition develops later.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
(2) <i><u>Cyclomerism Theory : ( Sedgwick,1884; Remane, 1950 )</u></i> </h3>
<div>
<br /></div>
<div>
(i) Four gastric or enterocoelic or enterocoelic pouches are separated from central gut.</div>
<div>
<br /></div>
<div>
(ii) Three pairs of coelomic cavities the protocoel, mesocoel & metacoel originate by division of 2 pouches.</div>
<div>
<br /></div>
<div>
(iii) Gradually protocoel & mesocoel are lost, only metacoel remain. </div>
<div>
Example :- Mollusca</div>
<div>
<br /></div>
<div>
(iv) Later division of metacoel produces primary segments.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h4>
<i><u>Evidence</u></i> :- </h4>
<div style="text-align: left;">
All bilateral matazoans were originally segmented and coelomate and the acoelomate unsegmented group ( flatworm, nemerteans ) have lost these characters secondarily.</div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
<br /></div>
<h3 style="text-align: left;">
(3) <i><u>Fission Theory ( Perrier, 1882)</u></i> :-</h3>
<div>
<br /></div>
<div>
(i) The ancestor animal was unsegmented.</div>
<div>
<br /></div>
<div>
(ii) By transverse fission during asexual reproduction produced a chain of sub individuals, which remained united end. so end due to incomplete separation.</div>
<div>
<br /></div>
<div>
(iii) Later those sub individuals become integrated morphologically and physiologically into one complex individuality.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<h4>
<i><u>Evidence</u></i> :- </h4>
</div>
<div>
<br /></div>
<div>
Occurs in some platyhelminthys and annelids today.</div>
<div>
<br /></div>
<div>
<br /></div>
<h4 style="text-align: left;">
<i><u>Opposition</u></i> :-</h4>
<div>
<br /></div>
<div>
(i) In some platyhelminthys and scyphozoans fission occurs always somewhere in the middle of the chain.</div>
<div>
<br /></div>
<div>
(ii) Reproduction by fission is usually confined to sessile animals, but the ancestor were probably free swimming.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i><u>Significance</u></i> :- </h3>
<div>
<br /></div>
<div>
(i) It has provided effective locomotory mechanism coordinated contraction along body generates efficient body undulating movement.</div>
<div>
<br /></div>
<div>
(ii) Fluid filled coelomic compartments provide hydro static skeletons for burrowing. Different turger pressure </div>
<div>
are effected by flow of coelomic fluid from one part of the body to the other.</div>
<div>
<br /></div>
<div>
(iii) Different segments can be specialized for different functions- which leads to the development of organization. It is not clearly marked in annelids, but well developed in arthropods. example- Spermatheca, clitellium are involved with reproduction, thus regional specification of the body with proper division of labour.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div style="text-align: left;">
<br /></div>
<div style="text-align: left;">
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com2tag:blogger.com,1999:blog-2703452670950399845.post-91051026127486803772013-03-19T19:35:00.000+05:302013-06-13T12:49:29.895+05:30Introduction & Types of Metamerism<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><br /></u></i></h2>
<h2 style="text-align: left;">
<i><u>Introduction </u></i>:-</h2>
<div>
<br /></div>
<div>
In some animals, the body is divided into a series of compartments arrange one behind to the other. These compartments are called segments or somites or metameres. The Linear arrangement of segments one behind the other is called Metamerically segmented. </div>
<div>
<br /></div>
<div>
<b><i>Example</i></b> :- Annelida, Arthropoda & Chordata . </div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<h2 style="text-align: left;">
<b><i><u>Types of Metamerism</u></i></b> :- </h2>
</div>
<div>
<br /></div>
<h3 style="text-align: left;">
(i) <i><u>True Metamerism</u></i> :- </h3>
<div>
<br /></div>
<div>
True Metamerism is found in Annelids, Arthropods & Chordates. In true metamerism, the segmentation of the body is based on the segmentation of mesoderm. New segments are formed at the posterior end (in front of the anal segment ). Hence the youngest segments occur at the anterior end. The segments work in co- operation with all other segments.</div>
<div>
<br /></div>
<h3 style="text-align: left;">
(ii) <i><u>Pseudo Metamerism / Superficial Metamerism</u></i> :- </h3>
<div>
<br /></div>
<div>
Pseudo metamerism is exhibited by tape worms(Platyhalminthes). Here the segmentation of the body is based on the segmentation of ectoderm. New segments are formed at the anterior end (just behind the scolex). Hence the youngest segments occur at the anterior end & the old segments occur at the posterior end. The segments works as independent units. These is no co-operation between the segments.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i>(iii) <u>Homonomous Segmentation</u> :-</i> </h3>
<div>
<br /></div>
<div>
If all the segments of an animals are identical, the segmentation is called homonomous segmentation. The homonomous segmentation is not found in any existing animal as at least a few of the anterior segments are always specialization is called Cephalization. The closest approach to homonomous segmentation is found in some polychaetes in which all the segments between the head and the anal segment are alike-Homonomous segmentation is a primitive condition.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i>(iv) <u>Heteronomous Segmentation</u> :-</i> </h3>
<div>
<br /></div>
<div>
If the segments are dissimilar, the segmentation is called Heteronomous segmentation. </div>
<div>
<br /></div>
<div>
<b>Examples</b> :- Arthropods & Chordates.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3>
<i>(v) <u>External Metamerism</u> :- </i></h3>
<div>
<i><br /></i></div>
<div>
In Arthropods the metamerism is external. Internally the segments are not marked by partitions.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i>(vi) <u>External & Internal Metamerism</u> :- </i></h3>
<div>
<i><br /></i></div>
<div>
In Annelids the segmentation is marked externally as well as internally. Internally, the segments are separated by transverse partition called Septa.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i>(Vii) <u>Complete Metamerism</u> :-</i> </h3>
<div>
<br /></div>
<div>
When segmentation is seen in all the organs, the metamerism is called Complete Metamerism.</div>
<div>
<br /></div>
<div>
<b><i>Example</i></b> :- Annelida</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i>(viii)</i> <i><u>Incomplete Metamerism</u> :-</i> </h3>
<div>
<br /></div>
<div>
When segmentation is not seen in all organs, the metamerism is called Incomplete Metamerism.</div>
<div>
<br /></div>
<div>
<b><i>Examples </i></b>:- Arthropoda & Chordata</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-17604611739811453892013-03-10T23:53:00.000+05:302013-06-13T12:50:15.331+05:30Classification of Phylum Arthropoda<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<u style="font-style: italic;"><br /></u></h2>
<h2 style="text-align: left;">
<u style="font-style: italic;">Phylum</u><span style="font-weight: normal;"> </span>:- <i><u>Arthropoda</u></i></h2>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<h3 style="text-align: left;">
<i><u>Characters </u></i>:- </h3>
<div>
(i) A pair of externally jointed appendages is usually present in each segment.</div>
<div>
<br /></div>
<div>
(ii) Body is externally covered by thick, tough & chitinous cuticle, forming the exoskeleton.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h2>
<u style="font-style: italic;">SubPhylum</u><span style="font-weight: normal;"> :- </span><i><u>Crustacea</u></i></h2>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:- </h3>
</div>
<div>
(i) Head bears five pairs of appendages which comprises of two pairs of antennae & two pairs of maxilla.</div>
<div>
<br /></div>
<div>
(ii) Respiration usually through gills.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<u style="font-style: italic;">Class</u><span style="font-weight: normal;"> </span>:- <i><u>Branchiopoda</u></i></h3>
<div>
<br /></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:- </h3>
</div>
<div>
(i) Trunk appendages are flattened leaf like structure.</div>
<div>
<br /></div>
<div>
(ii) Coxa is provided with a flattened epipod.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Examples </i></b>:- Triopes(tadpole shrimp); Daphnia; Artemia;</div>
<div>
<br />
<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTfkCMGsSFTHbE4yqOHIYUQramGJius4wnSF4rSe8SiAQGWUf0qYI4xENyCQI10y6lB6OCDH59jhX1hxfSHAN6kYqKEuOiN5L1U8o0Dv1rWstgdTTloLGONcKTG2FW_T0HQQxflPkJS0Q/s1600/Triopes.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="175" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjTfkCMGsSFTHbE4yqOHIYUQramGJius4wnSF4rSe8SiAQGWUf0qYI4xENyCQI10y6lB6OCDH59jhX1hxfSHAN6kYqKEuOiN5L1U8o0Dv1rWstgdTTloLGONcKTG2FW_T0HQQxflPkJS0Q/s200/Triopes.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Triopes</td></tr>
</tbody></table>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-zdbQRPi13t47JMgVo-pzyEuYmDhl6X56geTeVrn7_H64_ID7uC2awxiMuJ-cYSQnlmSRTG2m5YoUdsASB7YRD8GjspK-LzwSrlimJ-U3E6VA3zwpM08m07Avoeyl_MohyphenhyphenGaiOVChi-Q/s1600/Daphnia.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-zdbQRPi13t47JMgVo-pzyEuYmDhl6X56geTeVrn7_H64_ID7uC2awxiMuJ-cYSQnlmSRTG2m5YoUdsASB7YRD8GjspK-LzwSrlimJ-U3E6VA3zwpM08m07Avoeyl_MohyphenhyphenGaiOVChi-Q/s200/Daphnia.jpe" width="176" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Daphnia</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-PBPK6KHLTXF508cJr7eOGnOA-TRP0Uf8qyZCwvXo-9YPatIdUdKOibbeVaUNWYvyfIMSoCg9tvhdX7EMqCaXpiS0z-dPO3QOgRW60b-fMU0wleo4xj9N4EvmQ-sfXh1jXnMBeZtLKiE/s1600/Artemia.jpe" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="113" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-PBPK6KHLTXF508cJr7eOGnOA-TRP0Uf8qyZCwvXo-9YPatIdUdKOibbeVaUNWYvyfIMSoCg9tvhdX7EMqCaXpiS0z-dPO3QOgRW60b-fMU0wleo4xj9N4EvmQ-sfXh1jXnMBeZtLKiE/s200/Artemia.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Artemia</td></tr>
</tbody></table>
<br /></div>
<div>
<br /></div>
<div>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br /></div>
<div>
<h3>
<i><u>Class </u></i>:- <i><u>Ciripedia</u></i></h3>
</div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:-</h3>
</div>
<div>
(i) Body enclosed within a bivalve carapace.</div>
<div>
<br /></div>
<div>
(ii) Body is poorly segmented & most lack abdomen.</div>
<div>
<br /></div>
<div>
<i><u><br /></u></i></div>
<div>
<b><i>Examples </i></b>:- Lepas; Balanus; Sacculina;<br />
<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPyKdM7bwjNh2fBZSWUvN-N-fDPCpe-ZBrVo5UCjp97gF98dmSoeWXbpyjw1B-4F-YsKIaY0mjQHZql8PYcd2jnZWCYNLNF869PsYnMDN5tjsRHTdM7R3t2FvQwUKirR2M0RWWblzvUKw/s1600/Balanus.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="149" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPyKdM7bwjNh2fBZSWUvN-N-fDPCpe-ZBrVo5UCjp97gF98dmSoeWXbpyjw1B-4F-YsKIaY0mjQHZql8PYcd2jnZWCYNLNF869PsYnMDN5tjsRHTdM7R3t2FvQwUKirR2M0RWWblzvUKw/s200/Balanus.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Balanus</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMp-vnXCnERzDtjj3z8UjpC3OBz0Atoy-4BAZOHJuQsLEwcUhDj-9uZ6KA5tNIv_YCAJuTIfPTW_eCBg7BbsgUO2VOUhjMYz5KgMxtBwXr8s42Djksf6jMbYTtIKZiVBxLaKJNhxgZLuY/s1600/Lepas+anserifera.jpe" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="149" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMp-vnXCnERzDtjj3z8UjpC3OBz0Atoy-4BAZOHJuQsLEwcUhDj-9uZ6KA5tNIv_YCAJuTIfPTW_eCBg7BbsgUO2VOUhjMYz5KgMxtBwXr8s42Djksf6jMbYTtIKZiVBxLaKJNhxgZLuY/s200/Lepas+anserifera.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Lepas</td></tr>
</tbody></table>
<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiefIg3EqRvEWvZNlx9Lh1KmB0Zo4rktBB9gftXTDID10lXGexWOzgdaSxzIo1jzzPOqC185lw-m5c1XxmagyjGMEknNJ8l17aToz-WWFWAG57BdziEArONVf6wzmjyJtS07jA-w1ziS0s/s1600/Sacculina+carcini.jpe" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="149" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiefIg3EqRvEWvZNlx9Lh1KmB0Zo4rktBB9gftXTDID10lXGexWOzgdaSxzIo1jzzPOqC185lw-m5c1XxmagyjGMEknNJ8l17aToz-WWFWAG57BdziEArONVf6wzmjyJtS07jA-w1ziS0s/s200/Sacculina+carcini.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- <span style="font-size: small; text-align: left;">Sacculina</span></td></tr>
</tbody></table>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<h3>
<i><u>Class </u></i>:- <i><u>Malacostraca</u></i></h3>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:-</h3>
</div>
<div>
(i) Body comprises of head, an eight segmented thorax & six segmented abdomen.</div>
<div>
<i><u><br /></u></i></div>
<div>
(ii) The posterior thoracic limbs being walking legs, the 1st five pairs of abdominal ones forming swimming organs.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Examples </i></b>:- Squilla; Hippa; Macrobrachium(prawn); Cancer;</div>
<div>
<br /></div>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMK8NpVSQID1XvDcL3TC4PBQPxTQ7M13En0hiwjOt2byVIhtPXJQZqDJNPvwbPgcccYcdgFiGk6jwMv8k5V7p6-u9U_Yslma0cFOlVrXNLJCCFo2umY7BNpGchBLfWcs4AZgKzFLHSHRY/s1600/Squilla.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMK8NpVSQID1XvDcL3TC4PBQPxTQ7M13En0hiwjOt2byVIhtPXJQZqDJNPvwbPgcccYcdgFiGk6jwMv8k5V7p6-u9U_Yslma0cFOlVrXNLJCCFo2umY7BNpGchBLfWcs4AZgKzFLHSHRY/s200/Squilla.jpe" width="93" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Squilla</td></tr>
</tbody></table>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgkNKIVi8n8pCL6yMZ1ol8RaxaA8zIpJkODTrbf3-ieXtvWhqxZZ7WiIPdlhN9PBnOK6rQ-dG8LfV3lMUReMGGbtubhU8QOeKTFktGlYQ2o0WkvnQr-EXFqdlx8ph_jD2m8bKkBJ9nxlc/s1600/MACROBRACHIUM.jpe" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="109" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgkNKIVi8n8pCL6yMZ1ol8RaxaA8zIpJkODTrbf3-ieXtvWhqxZZ7WiIPdlhN9PBnOK6rQ-dG8LfV3lMUReMGGbtubhU8QOeKTFktGlYQ2o0WkvnQr-EXFqdlx8ph_jD2m8bKkBJ9nxlc/s200/MACROBRACHIUM.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Macrobrachium</td></tr>
</tbody></table>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br /></div>
</div>
<div>
<h2>
<u style="font-style: italic;">SubPhylum</u><span style="font-weight: normal;"> :- </span><i><u>Uniramia</u></i></h2>
<div>
<br /></div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:-</h3>
</div>
</div>
<div>
(i) Appendages are uniramous<br />
<br />
<br />
<br />
<br />
<h3>
<i><u>Class </u></i>:- <i><u>Diplopoda</u></i></h3>
</div>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:- </h3>
</div>
<div>
(i) Presence of double trunk segments, which are either cylindrical or somewhat flattened.</div>
<div>
<br /></div>
<div>
(ii) Presence of calcified exoskeleton.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<i><u><br /></u></i></div>
<div>
<b><i>Example </i></b>:- Julus<br />
<br /></div>
<div>
<br /></div>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqg0ZqMA9_zvggNVbpVwSrBcbAA6r2HxC2BTqfKhZQU9E6AoT47slMyqp22PrQd5OD88UN6YdPkEg6CknVOnyEnm8wfO1W-CkkGVukS8_wakpVm4AyQxzWE60myZTO7QEldsfbMqffISk/s1600/Julus.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="132" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqg0ZqMA9_zvggNVbpVwSrBcbAA6r2HxC2BTqfKhZQU9E6AoT47slMyqp22PrQd5OD88UN6YdPkEg6CknVOnyEnm8wfO1W-CkkGVukS8_wakpVm4AyQxzWE60myZTO7QEldsfbMqffISk/s200/Julus.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- <span style="font-size: small; text-align: left;">Julus</span></td></tr>
</tbody></table>
<br />
<br />
<br />
<br />
<br />
<br />
<br /></div>
<div>
<br />
<br />
<br />
<br />
<br /></div>
<div>
<h3>
<i><u>Class </u></i>:- <i><u>Insecta</u></i></h3>
</div>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:- </h3>
</div>
<div>
(i) Head formed by the fusion of 6 segments, typically bears a single pairs of antennae & two pairs of maxillae.</div>
<div>
<br /></div>
<div>
(ii) The trunk in insects subdevided into three segmented thorax & an abdomen of 11 segments without walking legs.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Examples </i></b>:- Lepisma(silver fish); Periplaneta; Carausias(stick insect);Bombyx; Anopheles;<br />
<br />
<br /></div>
<div>
<br /></div>
<div>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_GhkyLiAp9R7pAZ5JPPf9_ysx4fBehAgxddRtNgO16nRGm8ITEp1lfK4E3WeF5YqheN8wMvTkgm-g1FxiDo3U_fuLWIM-ToPDiy69F2kG4rYdNK5T1hERdFfU7C4u0GPZaQK9MzwDfDY/s1600/Lepisma.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="133" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg_GhkyLiAp9R7pAZ5JPPf9_ysx4fBehAgxddRtNgO16nRGm8ITEp1lfK4E3WeF5YqheN8wMvTkgm-g1FxiDo3U_fuLWIM-ToPDiy69F2kG4rYdNK5T1hERdFfU7C4u0GPZaQK9MzwDfDY/s200/Lepisma.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Lepisma</td></tr>
</tbody></table>
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQM_7hViuThI_eXHKR2wNIOUZd2Rxanw0Ld_fFwjiwCUbPqRG1YrczQYLe0igbKsH2rHDrmVUoUkaieH9yUleGFGgniv8JxOX6cH7dANXVce3S6yyQk23lZnBVzykszQxtapbecWunEpU/s1600/Periplaneta.jpe" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="135" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQM_7hViuThI_eXHKR2wNIOUZd2Rxanw0Ld_fFwjiwCUbPqRG1YrczQYLe0igbKsH2rHDrmVUoUkaieH9yUleGFGgniv8JxOX6cH7dANXVce3S6yyQk23lZnBVzykszQxtapbecWunEpU/s200/Periplaneta.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Periplaneta</td></tr>
</tbody></table>
<br />
<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhY2AK9GkwoBnglt3nEcnL1bE7M4RF27kBSxRQU4ZnlYNrR04T9sZKImk1ASc3Cm7tX1WNspem8IUEx4gurptot56ApKf1WgngjRx1PaHCBiwo5VuBlvfEqLG3YgLe_VivKGxlw9sUCglY/s1600/Bombyx.jpe" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="133" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhY2AK9GkwoBnglt3nEcnL1bE7M4RF27kBSxRQU4ZnlYNrR04T9sZKImk1ASc3Cm7tX1WNspem8IUEx4gurptot56ApKf1WgngjRx1PaHCBiwo5VuBlvfEqLG3YgLe_VivKGxlw9sUCglY/s200/Bombyx.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Bombyx</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFxobPTYVmOsFMqivSIaUPMNybpQiCBP_Aedbta1ejDDkZ4SrrnSFpIpujiRe6HgJQoWlMOL4O1-D7VI60nEu-ldi2QDQ_rrEtAcdu2Ycl6C9JPPIN5y4w_JeqbwgsZP1c9NvN_Uv4qOM/s1600/Anopheles.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="133" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiFxobPTYVmOsFMqivSIaUPMNybpQiCBP_Aedbta1ejDDkZ4SrrnSFpIpujiRe6HgJQoWlMOL4O1-D7VI60nEu-ldi2QDQ_rrEtAcdu2Ycl6C9JPPIN5y4w_JeqbwgsZP1c9NvN_Uv4qOM/s200/Anopheles.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Anopheles</td></tr>
</tbody></table>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br /></div>
<div>
<h2>
<u style="font-style: italic;">SubPhylum</u><span style="font-weight: normal;"> :- </span><i><u>Chelicerata</u></i></h2>
</div>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:- </h3>
</div>
<div>
(i) Body divided into an anterior cephalothorax or prosoma, which wholly or partially covered by a dorsal carapace & a posterior abdomen or opsthosoma.</div>
<div>
<br /></div>
<div>
(ii) Lack of antennae.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<h3>
<i><u>Class </u></i>:- <i><u>Merostomata</u></i></h3>
</div>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<u style="font-style: italic;">Characters</u><span style="font-weight: normal;"> </span>:- </h3>
</div>
<div>
(i) A prominent spike like caudal spine or telson is present at the end of the body.</div>
<div>
<br /></div>
<div>
(ii) Prosoma is covered by a large, horse shoe shaped carapace.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
</div>
<div>
<b><i>Example </i></b>:- Limulus</div>
<div>
<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEghf2IlLkeSzOV2AL03ZBOPfI68l7NtUboI0_S7VbUCYZElTAMBlVNsIawl87dlqD3mSbEpbo9mw5qZMq2LQJLbJ-U3M_SLnKBpehSQ7qli894DFEawTdN5ltY4vOGbAVam7hUR5SxiaZQ/s1600/Limulus.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="113" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEghf2IlLkeSzOV2AL03ZBOPfI68l7NtUboI0_S7VbUCYZElTAMBlVNsIawl87dlqD3mSbEpbo9mw5qZMq2LQJLbJ-U3M_SLnKBpehSQ7qli894DFEawTdN5ltY4vOGbAVam7hUR5SxiaZQ/s200/Limulus.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- <span style="font-size: small; text-align: left;">Limulus</span></td></tr>
</tbody></table>
<br /></div>
<div>
<br /></div>
<div>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0tag:blogger.com,1999:blog-2703452670950399845.post-62525649289197859482013-03-10T23:14:00.003+05:302013-06-13T12:51:00.114+05:30Classification of Phylum Platyhelminthes<div dir="ltr" style="text-align: left;" trbidi="on">
<div dir="ltr" style="text-align: left;" trbidi="on">
<h2 style="text-align: left;">
<i><u><br /></u></i></h2>
<h2 style="text-align: left;">
<i><u>Phylum </u></i>:- <i><u>Platyhelminthes</u></i></h2>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<h3 style="text-align: left;">
<i><u>Characters </u></i>:- </h3>
<div>
<br /></div>
<div>
(i) Body bilaterally symmetrical & dorsoventrally flattened.</div>
<div>
<br /></div>
<div>
(ii) Digestive system had a single opening or mouth, that leads to a well developed gastrovascular cavity absent & anus absent.</div>
<div>
<br /></div>
<div>
<br /></div>
<h3 style="text-align: left;">
<i><u>Class </u></i>:- <i><u>Tubellaria</u></i></h3>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<i><u>Characters </u></i>:-</h3>
</div>
<div>
<br /></div>
<div>
(i) Turbellarian are mainly free living, aquatic, but there are some terristrial sp.</div>
<div>
<br /></div>
<div>
(ii) Hermaphrodite, with internal fertilization.</div>
<div>
<br /></div>
<div>
<br />
<br /></div>
<div>
<b><i>Example </i></b>:- Planeria (free living)<br />
<br />
<br /></div>
<div>
<br /></div>
<div>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjC05gP4ZtMGBvadYSi1YBwbdfWh8XCt4xy3P8diQcwa7mkLgTas0C_ih2dInZCHTzvXoaaFGyWyBu1gqlA_g1ZB-BMYgXDtMKhp3gUVxlajt_zvQjxGcXh_RWkCLl9oM6rSj7lqSFhp-s/s1600/Planeria.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="169" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjC05gP4ZtMGBvadYSi1YBwbdfWh8XCt4xy3P8diQcwa7mkLgTas0C_ih2dInZCHTzvXoaaFGyWyBu1gqlA_g1ZB-BMYgXDtMKhp3gUVxlajt_zvQjxGcXh_RWkCLl9oM6rSj7lqSFhp-s/s200/Planeria.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Planeria</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgnvc9oxvEJSe5G-rxN1XFjIDeq1K9Ujt3LgEDftLWoGtudH9K41_7UUKy8sOPf-oSEA_iHCwmkl_BHQi8Rj6A6PzY0a80UP_LX_GY2PtpZEhTzMIUJNlKjOZNOaX9A7zw1mbsScvyYHM0/s1600/Planeria+anatomy.jpe" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="149" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgnvc9oxvEJSe5G-rxN1XFjIDeq1K9Ujt3LgEDftLWoGtudH9K41_7UUKy8sOPf-oSEA_iHCwmkl_BHQi8Rj6A6PzY0a80UP_LX_GY2PtpZEhTzMIUJNlKjOZNOaX9A7zw1mbsScvyYHM0/s200/Planeria+anatomy.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Planeria anatomy</td></tr>
</tbody></table>
<br />
<br />
<br />
<br />
<br />
<br />
<br /></div>
<div>
<br /></div>
<div>
<h3>
<i><u><br /></u></i></h3>
<h3>
<i><u><br /></u></i></h3>
<h3>
</h3>
<h3>
<i><u>Class </u></i>:- <i><u>Trematoda</u></i></h3>
</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<h3>
<i><u>Characters </u></i>:-</h3>
</div>
<div>
<br /></div>
<div>
(i) Body cylindrical or leaf shaped & parasitic.</div>
<div>
<br /></div>
<div>
(ii) Body is covered by cuticle, which provides protection against host enzyme action & defence mechanism.</div>
<div>
<br /></div>
<div>
<br />
<br /></div>
<div>
<b><i>Examples </i></b>:- Fasciola; Schistosoma; Aspidogaster;<br />
<br />
<br /></div>
<div>
<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbf48ufvKhyYAmLXLLHuL5ZQDD3g6DoBVs5dow8tlwhuJs6xbsaEesAUMTjbBtDhEHTIbB2Fr9q4sNJjHkCklVkfCnlrRU2JPmm8dy6TBJfzC5syBoiQC8viwDflUWxwr264SiMvNMQu0/s1600/Fasciola.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="149" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhbf48ufvKhyYAmLXLLHuL5ZQDD3g6DoBVs5dow8tlwhuJs6xbsaEesAUMTjbBtDhEHTIbB2Fr9q4sNJjHkCklVkfCnlrRU2JPmm8dy6TBJfzC5syBoiQC8viwDflUWxwr264SiMvNMQu0/s200/Fasciola.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Fasciola</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEu0HF_SPtvooKLAEdAolsAfGDwSBiS2Fe6SNuHtmifTsMedBQQHdrZmiKADJc5xorlZpO5ARWxOziCfccHHkY2dhtzx1u-xW8C6uX-3TjydCSCVueahm82svEMqJcVZZG-5pyVuYy2hc/s1600/Schistosoma.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="147" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEu0HF_SPtvooKLAEdAolsAfGDwSBiS2Fe6SNuHtmifTsMedBQQHdrZmiKADJc5xorlZpO5ARWxOziCfccHHkY2dhtzx1u-xW8C6uX-3TjydCSCVueahm82svEMqJcVZZG-5pyVuYy2hc/s200/Schistosoma.jpg" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- <span style="font-size: small; text-align: left;">Schistosoma</span></td></tr>
</tbody></table>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br /></div>
<div>
<br /></div>
<div>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMiKYOT-XiR_VACd1lqSkTQrbGb3QFHtdAPOcHMz486U7OZ2Yz_GIHSKYHWaT5Ec8CgmsF6dVfYu-hhBX4EJdceBo0hqVas5XjGMWIvO0_6iU6Gt5ZEmdYuWTFJiKrSVG9gZw2jr_JcI4/s1600/Aspidogaster.jpg" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgMiKYOT-XiR_VACd1lqSkTQrbGb3QFHtdAPOcHMz486U7OZ2Yz_GIHSKYHWaT5Ec8CgmsF6dVfYu-hhBX4EJdceBo0hqVas5XjGMWIvO0_6iU6Gt5ZEmdYuWTFJiKrSVG9gZw2jr_JcI4/s200/Aspidogaster.jpg" width="127" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- <span style="font-size: small; text-align: left;">Aspidogaster</span></td></tr>
</tbody></table>
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br /></div>
<div>
<h3>
<i><u><br /></u></i></h3>
<h3>
<i><u><br /></u></i></h3>
<h3>
<i><u><br /></u></i></h3>
<h3>
<i><u><br /></u></i></h3>
<h3>
<i><u>Class </u></i>:- <i><u>Cestoidea</u></i></h3>
</div>
<div>
<i><u><br /></u></i></div>
<div>
<i><u><br /></u></i></div>
<div>
<h3>
<i><u>Characters </u></i>:-</h3>
</div>
<div>
<br /></div>
<div>
(i) Endoparasitic helminth, whose body is covered by a syncytial tegument.</div>
<div>
<br /></div>
<div>
(ii) Organs of attachment in the form of hooks & suckers are present.</div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<br /></div>
<div>
<b><i>Examples </i></b>:- Taenia; Echinococcus;</div>
<div>
<br /></div>
<div>
<br />
<br /></div>
<div>
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: left; margin-right: 1em; text-align: left;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiN6F76e4qgIZm-kZf-1QphS40OM07j3_GFrsESd31JVgu8gGAEMhpVKtydQtlU4OnspUNMnEohKIfS_BPyJQWcTVcrgz_25rOna-3-S2LyGdAyzM9ltj5Myx1OrkPhHjOGwYSBjyEXgWM/s1600/Taenia.jpe" imageanchor="1" style="clear: left; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="144" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiN6F76e4qgIZm-kZf-1QphS40OM07j3_GFrsESd31JVgu8gGAEMhpVKtydQtlU4OnspUNMnEohKIfS_BPyJQWcTVcrgz_25rOna-3-S2LyGdAyzM9ltj5Myx1OrkPhHjOGwYSBjyEXgWM/s200/Taenia.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- Taenia</td></tr>
</tbody></table>
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifxjtlsD77tDvIVeSG3291nibigw-qClCfli6iT9RoSHFm_UlS3RIjdnkFCQE74FVg_bERjAl_1dYmQZqGhxQiInx_7AcUZYXDQG99CwBaZqwHPjylnl9kgK9FjKVQVpnzqtXAKK9ZeME/s1600/Echinococcus.jpe" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="136" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifxjtlsD77tDvIVeSG3291nibigw-qClCfli6iT9RoSHFm_UlS3RIjdnkFCQE74FVg_bERjAl_1dYmQZqGhxQiInx_7AcUZYXDQG99CwBaZqwHPjylnl9kgK9FjKVQVpnzqtXAKK9ZeME/s200/Echinococcus.jpe" width="200" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Fig :- <span style="font-size: small; text-align: left;">Echinococcus</span></td></tr>
</tbody></table>
<i><u></u></i><br />
<i><u></u></i>
<i><u></u></i>
<i><u></u></i>
<i><u><br /></u></i>
<i><u><br /></u></i>
<i><u><br /></u></i>
<i><u><br /></u></i>
<i><u><br /></u></i>
<i><u><br /></u></i>
<i><u><br /></u></i></div>
<div>
<br /></div>
<div>
<br /></div>
</div>
<a href="http://www.neobux.com/?r=rajamallick5"><img height="60" src="http://images.neobux.com/imagens/banner8.gif" width="468" /></a>
<a href="http://www.clixsense.com/?5204510" target="_blank"><img border="0" src="http://csstatic.com/banners/clixsense468x60d.png" /></a>
<a href="http://www.clickfair.com/?ref=rajamallick" target="_blank"><img border="0" height="60" src="http://www.clickfair.com/banners/468-1.gif" width="468" /></a>
<!-- Begin BidVertiser code -->
<script language="JavaScript1.1" src="http://bdv.bidvertiser.com/BidVertiser.dbm?pid=530767&bid=1323609" type="text/javascript"></script>
<noscript><a href="http://www.bidvertiser.com/bdv/BidVertiser/bdv_advertiser.dbm">internet marketing</a></noscript>
<!-- End BidVertiser code -->
<script type="text/javascript">
ch_client = "rajamallick";
ch_width = 550;
ch_height = 250;
ch_type = "mpu";
ch_sid = "Chitika Default";
ch_color_site_link = "0000CC";
ch_color_title = "0000CC";
ch_color_border = "FFFFFF";
ch_color_text = "000000";
ch_color_bg = "FFFFFF";
</script>
<script src="http://scripts.chitika.net/eminimalls/amm.js" type="text/javascript">
</script>
</div>
RAJAhttp://www.blogger.com/profile/05623794365401110211noreply@blogger.com0