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!
Class Polychaeta - Classification of Coelom
There are mainly marine forms with distinct head, having eyes and tentacles, segments have lateral projections of the body wall termed as parapodia which carry bundles of setae. These animals do not have clitellum. Sexes are separating (dioecious). They have no different or permanent sex organs, but their gonads consist of masses of developing gametes arising as swellings of Peritoneum. Eggs generally develop into trochophore larva. Many forms reproduce asexually by budding. ? Most of the polychaetes are 5-10 cm long. They live below rocks and in crevices, or burrow in mud. Some build tubes. Other is pelagic. These animals are generally divided into
(1) Errant forms on the one hand that are freely moving, pelagic, active burrowers, crawlers and the tube worms which leave their tubes for several purposes. On the other hand
(2) The sedentary forms do not leave their tubes or burrows but may generally expose just only their heads outside.
Errant polychaete structure may be considered classic of a generalised polychaete. The prostomium is very well developed, with several sense organs such as eyes, antennae, palps and the nuchal organs. Prostomium is dorsal and preoral projecting over the mouth. The peristomium that is the first segment carries the mouth. The predatory forms have jaws in the mouth. The peristomium is often fused along with one or more subsequent segments forming the head. These segments as well usually carry sensory structures, but their parapodium as well bears bundles of chitinous setae in the setal sacs. Nereis is a typical example. A cross section of its body by one of its middle segments shows well its internal organisation.
What are the consequences of iodine deficiency disorders? As discussed earlier under signs and symptoms, the consequences of IDD include: mental retardation, other defects in t
Q. Symptoms of gastro oesophageal reflux disease? Most commonly, people with GERD complain of heartburn, a painful or uncomfortable feeling in the chest, which may radiate to t
why protozoass dont have vaccines esp. plasmodiums
In the preceding section we emphasised the fact that cvolution or the continuous adaptations to the environment can take place only when pheiiotypes exhibit variability. In the abs
MICROTUBULES Discovered by De Robertis and Franchi . Term given by Slautterback . These are hollow structures, consists of tubulin protein. Each protein diamer
What are the different mechanisms responsible for corneal avascularity? Various mechanisms responsible for its avascularity are as follows: a) Chemical Theory: I) Role o
EARTHQUAKES An earthquake with its terrible aftereffects is one of the most frightening and destructive phenomena of nature. It can be defined as a sudden movement of
Pollen Stigma Interaction - Stigma The Stigma After landing on the stigma pollen grain germinates, and produces a pollen tube that carries the male gametes. The stigma has bee
MUSCULOSKELETAL SYSTEM: Disease of the skin and musculoskeletal system occur commonly in early age group. There are not many statistics to prove the exact frequency of
Q. What are the major purposes of the organic molecules for living beings? Ans. Organic molecules, like, lipids, carbohydrates and proteins perform several functions for
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