Metamorphosis in amphibians, Biology

Assignment Help:

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.


Related Discussions:- Metamorphosis in amphibians

Determine the number of gametes, An organism has 16 chromosomes in its soma...

An organism has 16 chromosomes in its somatic cells. Determine the number of gametes with different chromosome compositions that it can potentially create. Explain your answer. Ign

Ammonia assimilation, Ammonia Assimilation - Inorganic Nitrogen and Sulphur...

Ammonia Assimilation - Inorganic Nitrogen and Sulphur Metabolism Nitrogen (N 2 ) gas and NO 3 are the most common available forms of inorganic nitrogen. Both are enzymaticall

How to repair the defects in post myocardial , How to repair the defects in...

How to repair the defects in post myocardial ? Repair of Defect :  The approach to the defect is through ventriculotomy over the infarcted area. The defect is repaired

What are the blood types of the abo blood system, What are the blood types ...

What are the blood types of the ABO blood system? The type A, the type B, the type AB and the type O are the blood types of the ABO blood system..

Define dietary goals in parkinson''s disease, Define Dietary Goals in Parki...

Define Dietary Goals in Parkinson's Disease? The main goals include: - Maintain desirable weight - Promote absorption of anti- Parkinson's drug levodopa - Lessen swall

Body fluids of marine teleost, Body Fluids of Marine Teleost The body ...

Body Fluids of Marine Teleost The body fluids of marine teleost are hypotonic to seawater, so these fishes lose water to the environment especially across the gill epithelium.

What is haccp and what is its significance?, Normal 0 false ...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

Burrowing - mechanics of locomotion, Burrowing - Mechanics of Locomotion ...

Burrowing - Mechanics of Locomotion Some polychaetes are burrowing. Instance is glycerides and capitellidae. Their parapodia are smaller. Burrowing is done by protrusion of pr

Can you explain bayesian theorem, Q. Can you explain Bayesian Theorem? ...

Q. Can you explain Bayesian Theorem? Bayesian Theorem: The predictive value of a test is related to the incidence of disease in the population. A history of typical angin

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd