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.
Utilization of Alternate Feed Resources Use of alternate feed resources is one of the potential areas for augmenting feed resource base in the country. However, the use of NCF
SODIUM The element is available in table salt. A proper balance of sodium and potassium is essential. Its absorption is under control of aldasterone. The various f
Compare the modes of intercellular communication used by the endocrine and nervous systems and discuss the functional significance of the differences between the two systems.
Determine Functions of Zinc in the Body? Zinc is an essential component of a large number of enzymes participating in the synthesis and degradation of carbohydrates, lipids, pr
Phylum Tracheophyta Tracheophytes mean vascular plants. Tracheophyta includes ferns, the gymnosperms and the flowering plants. They have appeared some 400 million years ago, an
Describe Pathophysiology of tetralogy of fallots ? The PS causes concentric hypertrophy of right ventricle without enlargement. The right ventricular pressure are equal to or h
Adverse Effects of Famciclovir Famciclovir has been generally well tolerated. Headache, nausea and diarrhea have been reported. Like acyclovir, famciclovir has been associated
Explain the assessing and monitoring of peri-implant The parameters used for assessing and monitoring the peri-implant conditions need to be understood and applied judiciously
how to do a punnett square
Explain assessment of iron status - Transferrin saturation? Transferrin saturation: As iron deficiency progresses, there is a decline in transferrin saturation. With deficiency
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