Metamerism or segmentation, Biology

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).

Posted Date: 2/2/2013 12:26:58 AM | Location : United States

Related Discussions:- Metamerism or segmentation, Assignment Help, Ask Question on Metamerism or segmentation, Get Answer, Expert's Help, Metamerism or segmentation Discussions

Write discussion on Metamerism or segmentation
Your posts are moderated
Related Questions
A group working at the University of California, Berkeley has developed "nanothermometers," little nanoparticles that can be injected into cells to measure the temperature in vario

why frog respire through skin

Q. Provision of Additional Tooth Support? Transitioning a patient from a complete denture to an implant supported fixed prosthesis have resulted in a dramatic improvement in th

Q. What is metabolic disorders? In these metabolic disorders, since there is an inability to metabolize a specific amino acid the basis of dietary management is to restrict the

In general what is the phase of the menstrual cycle when copulation may lead to fecundation? Although this is not a rule, to be effective fecundation in general must happen wit

What is reflexive memory? Reflexive memory relies on the cerebellum and amygdala. Compare among aerobic respiration and anaerobic respiration. Aerobic respiration happens in th

Define the Importance of Zinc in Humans? Zinc deficiency in humans was reported by A.S. Prasad among people consuming mostly breads and very little animal protein in Middle Eas

Q. Effects of smoking on oesophagitis? 1. A decrease in pyloric sphincter pressure which may predispose an individual to duodenal ulcer. 2. An alteration in the nature of ga

Define the Process of Digestion of Fats? The enzyme in human gut which is responsible for fat digestion is 'lipase', Lipase is secreted by both stomach and pancreas. In stomach

how to calculate the frequency of mating with the HW equation?