Metameric segment - segmentation, Biology

Assignment Help:

Metameric segment - Segmentation

On the other hand true metameric segment as best observed in annelids has separate schizocoelic body cavity of mesodermal origin in each segment. Individual segments are budded off in linear sequence from a proliferation region just in front of the posterior end. Segmented animals have a specialized anterior acron (prostomium) and posterior pygidium or telson both of which are not segments. In between there are a varying number of segments.

In near perfect segmentation, appendages, musculature, ganglion, nerves, blood vessels, coelom and all body organs are replicated in each segment. This arrangement is best seen in annelids. In chordates, segmentation is usually apparent in the axial skeleton. Muscles and nerves. Why did segmentation evolve in animal groups? What advantages does it confer on the animals in which it is seen? Let us examine this a little closely. The most important advantage is that segmentation divides a body into a series of compartments, each of which can be regulated almost independently. This in a way provided the framework for specialization. In colonial animals this specialization is seen in polymorphism of zooids while in segmented animals regional specialization of segments occurs.


Related Discussions:- Metameric segment - segmentation

Left antero lateral thoracotomy approach, Left Antero Lateral Thoracotomy A...

Left Antero Lateral Thoracotomy Approach :  Arterial and central venous pressure monitoring lines are placed. A left antero lateral thoracotomy is done through the 5th or 4th

Buffalo-pox, B u f fa l o- p o x The disease i...

B u f fa l o- p o x The disease is caused by an orthopox virus, closely related to the vaccinia virus. It is not clear whether it should be considered

An mrna molecule codifies only one type of protein, An mRNA molecule codifi...

An mRNA molecule codifies only one type of protein? Eukaryotic cells have monocistronic mRNA, i.e., every mRNA codifies only one polypeptide chain. Prokaryotes can present poly

Define about the classification of polyphenols, Define about the Classifica...

Define about the Classification of polyphenols?  The various classes are: a) Phenolic acids and derivatives b) Flavonoids such as Flavonols and Flavones, Isoflavones and

Functions of endoplasmic reticulum, FUNCTIONS OF E.R. (1 )      Mecha...

FUNCTIONS OF E.R. (1 )      Mechanical support - E.R. participates in formation of cytoskeleton with microfilaments, microtubules and intermediate filaments. (2 )

Invertebrate groups possess segmented bodies, Which invertebrate groups pos...

Which invertebrate groups possess one, three, four or all of the features below?  Segmented bodies, hard exoskeleton, jointed legs, compound eyes, three pairs of walkin

In which phase mother exchanges substances to fetus, Exchange of oxygen, nu...

Exchange of oxygen, nutrients, carbon dioxide and waste products from mother to fetus takes place through diffusion across the: a) Chorionic villi (pron: core-e-on-ick villi)

Plant, what is comretun

what is comretun

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