Classification of multicellular animals - coelom, Biology

Assignment Help:

Classification of Multicellular Animals - Coelom

We know earlier that the pseudocoel gave animals specific selective benefits. Among other things, this fluid-tilled space worked as a hydrostatic skeleton increasing the efficiency of burrowing. However, in pseudocoelomates, organs lay loose in the body cavity. To circumvent this drawback, coelom evolved within mesoderm. The result was that the new body cavity, that is the coelom, came to be lined by mesodermal layer (peritoneal layer). The various organs also came to be suspended in the coelom through the mesodermal layer called mesenteries. This enabled the body wall to become much more muscular, with better developed longitudinal and circular muscles. The body cavity so became a more efficient hydrostatic skeleton now. The alimentary canal also became more muscular and more specialised. Various organs became better arranged in a much more stable way, without interfering with one another. The mesenteries as well served as a better medium for positioning blood vessels to the respective organs. So, development of coelom has been a main step in the evolution of more complex and larger animals.


Related Discussions:- Classification of multicellular animals - coelom

What is the rh typing of the mother, What is the Rh typing of the mother an...

What is the Rh typing of the mother and of the fetus in the hemolytic disease of the newborn? In the hemolytic disease of the newborn the mother is Rh- and the fetus Rh+. In th

Explain chilling temperatures - method of food preservation, Explain chilli...

Explain chilling temperatures - method of food Preservation? (a) Cellar storage temperatures (about 15° C): It is usually used for the storage of surplus foods like root crops,

Medical therapy for tricuspid stenosis, Q. Medical therapy for tricuspid st...

Q. Medical therapy for tricuspid stenosis? Medical therapy is ineffective. With diuretics, symptoms of congestion are replaced by that of low cardiac output state. Occasional c

Explanation of glomerular filtration, Question 1) Mentioning the 3 diff...

Question 1) Mentioning the 3 different processes in the formation of urine Explanation of Glomerular filtration Explanation of Tubular reabsorption Explanation of T

Molecular bio, he recombinant plasmid extracted from the surviving colonies...

he recombinant plasmid extracted from the surviving colonies contains a gene called SUC2 that codes for convertase, an enzyme needed to metabolize sucrose. Mutations in the SNF gen

Results-types of surgery, Results: Early mortality for tricuspid valve re...

Results: Early mortality for tricuspid valve replacement is around six per cent. But depending on the patient's class of symptoms and the number of concomitant procedures, this c

What is the fuction of starch, What is the fuction of Starch Starch is ...

What is the fuction of Starch Starch is the main thickener in gravies, sauces and puddings. Starch absorbs water, and  becomes a gel when cooked. As the starch swells up with w

Amphibians, respiratory system in amphibains

respiratory system in amphibains

How does biogeography contribute to an evolution, How does biogeography con...

How does biogeography contribute to an understanding of evolution? In biogeography studies, same animals that seem to be closely related are adapted to dissimilar environments

What is arteriole diameter, The axons of all the baroreceptors in the body ...

The axons of all the baroreceptors in the body were destroyed at 2 AM.  All else is normal.  Which of the following statements is true for the system at 2:10 AM when compared to th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd