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

Falling death rate, State the changes in society which could contribute to ...

State the changes in society which could contribute to a falling death rate. The changes in society which could contribute to a falling death rate are:  (i) improvements in

Point out some guidelines for breast-feeding, Point out some Guidelines for...

Point out some Guidelines for breast-feeding? 1) Follow demand feeding of the baby instead of a fixed schedule. 2) Initiate breast-feeding within 2 h after a normal delivery

Define the concept of health - public nutrition, Define the Concept of Heal...

Define the Concept of Health - Public Nutrition? The most widely accepted definition of health is the one given by WHO (1948) in the preamble to its constitution, Box 1 gives t

Kingdoms , phlum,class,characteristics of chromalveolata

phlum,class,characteristics of chromalveolata

Female reproductive system - graffian follicle, GRAFFIAN FOLLICLE - ...

GRAFFIAN FOLLICLE - It appears as knob or stigma in medulla. It is round, discovered by Graff. It is covered by 2 layers - thecae externa & theca interna. From theca i

Phylum protozoa, what is the classificatin of phylum protozoa with orders

what is the classificatin of phylum protozoa with orders

Apomixis, Apomixis The formation of sporophyte from the gametophyte w...

Apomixis The formation of sporophyte from the gametophyte without sexual process signifies apomixis. It relates to the replacement of alternation of a reduced gametophyte and

What we need undergloves, Q. What we need Undergloves? These are a cott...

Q. What we need Undergloves? These are a cotton glove worn under the treatment glove for those operators experiencing discomfort to the skin on the hands. These must be replace

Causes of solid wastes, The main causes for the rapid growth in the quantit...

The main causes for the rapid growth in the quantity of solid wastes are- (i)     Over population: the ever increasing population is increasing all types of pollution; same is t

Explain phenotypical characteristics of alleles of a gene, What are few exa...

What are few examples of phenotypical characteristics that present two or more varieties and of phenotypical features that do not vary? In relation to the genes correspondent 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