Metamerism or segmentation, Biology

Assignment Help:

Metamerism oe Segmentation

In the early coelomates the coelom was not divided into segments, the whole body cavity was a single space. Hence body movements were not precise. Though with evolution, coelom became divided into a number of chambers through partitions or septa made up of the mesodermal lining, the peritoneum. This increased the efficiency and precision of body movements, like individual segments could be moved more precisely now, with the same mechanism viz., hydrostatic or hydraulic pressure. As well, each segment came to have a repetition of many other organ systems such as circulatory, excretory, reproductive aid nervous systems. Each body segment is so more or less a repetition of the other and hence redundant; the animal can survive and function generally even if a few segments were lost. This phenomenon of divisions of body into a series of much more or less identical segments each containing a section of approximately all systems, is known as segmentation or metamerism. Each section of the body is termed as a segment or metamere. Metamerism has evolved independently at least two times in the animal kingdom in protostomes (Annelida - Arthropoda) and in Deuterostome (vertebrates).


Related Discussions:- Metamerism or segmentation

Six kingdom worksheet, what protist changes shape constantly and flows arou...

what protist changes shape constantly and flows around its food to engulf it?

Visceral larva migrans, Visceral larva migrans Visceral larva migrans,...

Visceral larva migrans Visceral larva migrans, also known as larval granulomatosis, is a clinical syndrome produced by the extra-intestinal migration of larval nematodes and i

What are the nutritional components of the foods we consume, What are the n...

What are the nutritional components of the foods we consume? The foods that we consume are composed of varying quantities of the following nutritionally important components:

Define the term probiotics, Normal 0 false false false ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Class of subphylum uniramia - pauropoda, Class of Subphylum Uniramia - Paur...

Class of Subphylum Uniramia - Pauropoda A small group of uniramians, there are 500 species of Pauropoda explained so far. The minute organisms computing about 1.5 mm in length

Explain the effect of deficiency of vitamin e, Explain the Effect of Defici...

Explain the Effect of Deficiency of Vitamin E? Fortunately, vitamin E deficiency in human is extremely rare. This may probably be due to its wide occurrence. in natural foods a

Discuss about nerve to mylohyoid, Nerve to Mylohyoid Motor branch of i...

Nerve to Mylohyoid Motor branch of inferior dental nerve which descends in a groove on the medial surface of the mandibular ramus. Surgical intervention in this area may lead

Phylum ciliophora - protozoan, Phylum Ciliophora - Protozoan Simple ci...

Phylum Ciliophora - Protozoan Simple cilia or compound ciliary organelles typical in at least one stage of life cycle; subpellicular cilia present even if surface cilia are ab

Advantage of using a patient''s own stem cells, What would be the advantage...

What would be the advantage of using a patient's own stem cells e.g. blood stem cells, to treat his or her illness? The benefit of using stem cells from the patient being trea

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