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!
Metamorphosis in Amphibians
Metamorphosis is radical in anurans, slight or not exists in urodeles. In anuran amphibians like toads and most frogs, metamorphosis is generally associated with a transition from an aquatic to a terrestrial or amphibious mode of life. Occasionally though no transition in mode of life takes place as observed in the larval and adult of the frog Xenopus laevis and many primitive anurans that remain aquatic throughout their life. The change in habitat in the frogs and toads also generally results in a change in their feeding habit. In some like X laevis there is no change in food habit because both larvae and adult ale carnivorous. Some anurans go through an abbreviated type of metamorphosis before hatching, as they pass through a tailed, gilled tadpole-like stage within the jelly membrane of the egg. Others go through direct development by skipping the larval stages totally.
Metamorphosis in urodele amphibians is generally less striking. Some of them undergo direct development, while others fail to complete their metamorphosis. The latter acquire sexual maturity as larvae, as seen in the axolotl larvae of Ambystoma. This phenomenon is termed as neoteny. Some urodeles like salamanders have been observed to go through two metamorphosis. Metamorphosis in both anurans and urodeles essentially includes the activation of the genomic set underlying the adult organization, which needs for its expression a minimum mass of tissue i.e. greater than that of the egg. The activation is believed to be due to the secretion of a brain hormone that initiates metamorphosis. The hormone triggers the degeneration of redundant larval organs and growth of hitherto quiescent structures that are needed in the adult. In amphibians the process of destruction and growth are smoothly coordinated, as a result of which the animal retains its functional integrity throughout metamorphosis in place of lying dormant as in the case of insects.
Seed A seed is a mature ovule enclosing an embryonic plant, stored food material (in endosperm, persistent nucellus or embryo itself) and a seed coat formed by one or two inte
male sex organ
M o dification of performance traits Modifications to livestock that could influence traits such as growth rate, feed efficiency and meat quality are major goals for livestoc
Which of the following results from the elimination of the sliding clamp? A. DNA polymerase will no longer be processive and will fall off the double helix after synthesizing
1 list the names of the phyla of animalike protists that have only free-living members
Solitary and Colonial Forms Animals may lead their lives either like individuals or in groups. While they exist as individuals, they are termed as solitary, but if they live i
Height of Plants - Quantitative Characters The height of a plant is a very good indicator of their general performance and therefore, can be employed as a criterion of the suc
Explain chilling temperatures - method of food Preservation? (a) Cellar storage temperatures (about 15° C): It is usually used for the storage of surplus foods like root crops,
Topical Route The medication in topical route is administered through ear, nose and eye. Drops are instilled into the nose, ear and eyes of the child in much the same way
Define Cyanmethaemoglobin Standard - Haemoglobin Content in Blood? Certified standard haemoglobin solution may be obtained from certified or reputed laboratory supply firms. St
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