Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Regional Specialisation
Regional specialisation takes place usually by three processes –
1) Restriction of certain structures to a few segments, for example, gonads are restricted to a few specialised genital segments in annelids (e.g. earthworm).
2) Structural divergence of segmental structures to perform different functions. For example some segmental appendages may be modified from those suitable for locomotion to those adapted for grasping or chewing, (e.g. insects)
3) Fusion of segments along the length of the animal. For example, fusion of anterior segments to form the head. The head of Nereis consists of the acron and two other segment while that of Drosophila is composed of five segments.
The second significant feature of metameric segmentation is its importance in the ' locomotion of soft bodied animals. The acoelomates animals use their musculature of longitudinal and circular muscles for locomotion but the evolution of a coelomic cavity has allowed the fluid to act as hydraulic skeleton. In invertebrates like annelids, muscles of the body wall act against this pressure. When circular muscles Contract, hydrostatic pressure on coelomic fluid will result in lengthening of the body; when longitudinal muscles contract, it will result in widening of the body. Since metameric segmentation results in compartmentalisation of the body, this elongation and widening of the body can be restricted to a few segments at a time.
This local change in the shape of the elongate body increases the locomotory efficiency. The broadened part of the body can be firmly fixed against the burrow especially if there are clinging structure such as setae and the lengthening of the body will produce considerable thrust resulting in progression of the animal. Thus the alternate peristaltic waves enable the animal to move forwards faster and efficiently.
What are biopolymers? Polymers are macromolecules made by the union of various smaller identical molecules, called monomers. Biopolymers are polymers present in the living bei
Pulmonary stenosis is a relatively common congenital heart defect. Usually these children with mild to moderate pulmonary stenosis survive into childhood. Since bicuspid pulmonary
Are the growth and development of plants only influenced by plant hormones? Chemical and Physical environmental factors, like position and intensity of light in relation to the
What is the physical experiment that show that the protoplasm has contractility?
What is Etherification The act or process of making ether; specifically, the process by which a large quantity of alcohol is transformed into ether by the agency of a small am
Bacteria never have a nucleus but some members of the domain Archaea are known to contain a true nucleus.
The overall goal of BCC programs for diabetes mellitus is to promote behaviors that control diabetes mellitus and prevent complications. These include: Following treatment
Q. Explain about Catheters and Guide Wires? The commonly used guide wires vary in diameter from 0.012 to 0.052; with 0.035 or 0.038 being the most commonly used sizes. The stan
Q. Why are glucorticoids used in transplant patients? In the treatment and prevention of this common problem patients are given other immunosupressants or glucorticoids, Glucoc
Explain Turnover number Turnover number:- The number of molecules of substrate transformed per catalytic site of the enzyme per minute,
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd