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

Why ph regulation is important for living beings, Q. Why pH regulation is i...

Q. Why pH regulation is important for living beings? How mineral salts participate in this regulation? The prospective of hydrogen (pH) is a measure of the amount of hydrogen i

Cleavage, CLE A V AG E - Holoblastic & unequal. First plane is meri...

CLE A V AG E - Holoblastic & unequal. First plane is meridional. 2 blastomeres are formed. 1 megamere & another micromere. 2nd plane is also meridional but at 90° to fir

Downers cow syndrome, D o w n e r s cow syndrome The Downer's co...

D o w n e r s cow syndrome The Downer's cow, otherwise known as creepers, is commonly a fatal condition of dairy animal associated with the unsuccessful treatment of cas

Where are blood cells made in the body, Where are blood cells made in the b...

Where are blood cells made in the body? Blood cells are made in the red bone marrow, e.g. in the ribs, sternum or vertebrae.

Biotechnology... what is the answer/, At a biotechnologist, employment oppo...

At a biotechnologist, employment opportunities can be found in many areas. In addition to biotechnology companies, where can a scientist with a biotechnology background find employ

How are the female gametes of gymnosperms formed, Q. How are the female gam...

Q. How are the female gametes of gymnosperms formed? What is the relationship between this process and the concept of alternation of generations? In the female strobiles (cones

Effects of malnutrition, Effects of malnutrition The effects of maln...

Effects of malnutrition The effects of malnutrition are not the same in adults and children. When the amount of food is not sufficient or when the nutrients are missing f

Transport of substances done across the bryophyte tissues, Q. How is the tr...

Q. How is the transport of substances done across the bryophyte tissues? How is this feature related to the general size of these plants? In bryophytes there are no nutrient-co

Explain observations seen in thyphoid, Some observations seen in this fever...

Some observations seen in this fever are: 1.  Massive loss of  lean body mass or muscle due to tissue breakdown (250-500 g muscle tissue is lost/day) leading to excessive nitro

Define the calcium toxicity, Define the Calcium Toxicity? Elevated bloo...

Define the Calcium Toxicity? Elevated blood calcium can occur in association with high parathyroid hormone, hyper- or hypothyroid conditions, bone metastasis, vitamin D toxicit

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