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.
Feline leukemia The disease is caused by a retrovirus and is the most common naturally occurring lymphosarcoma and accounts for nearly 30% of feline tumors. Based on the location
wdomestic effluent hat is
special character of leucosolenia
The Deoxyribonucleic acid or also called as DNA molecules are informational molecules encoding the genetic instructions used in the functioning and development of all known living
Potassium (K) - Macronutrients The main source of K + for plants comes from withering of K containing minerals. Potassium released by withering dissolves in the soil solution
Angiotensin receptor blockers block the final common pathway and provide a means of complete blockade of the system. One of two subtypes of AII receptors, the AT1 receptor produ
Q. PH of food in pectic ulcer? PH of food: It has. a little therapeutic importance except for patients with lesions in the mouth or oesophagus. Most foods are considerably les
Explain the Procedure for Preparation of General Purpose Media Procedure: Now prepare the media following the steps enumerated herewith: 1. Weigh and dissolve each ingredien
Explain Sickle cell anemia If 4% of a people are born with a severe form of sickle cell anemia. what percent of population will be resistant to malaria in spite of carrying
When constructing phylogenies using maximum likelihood methods, you assume?
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