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

Titanium and its alloys - alloplastic implant materials, Titanium and Its A...

Titanium and Its Alloys - Alloplastic implant materials These have been used primarily for their corrosion resistance and biocompatibility. Titanium exists in nature as a pure

What are imago and nymph, Q. What are imago and nymph? Nymphs are larva...

Q. What are imago and nymph? Nymphs are larvae of hemimetabolic insects (like grasshoppers). They are very similar to the adult insect although smaller, In holometabolic insect

Determine about the halstead''s method, Determine about the Halstead's meth...

Determine about the Halstead's method Reitan adopted Halstead's methods and various test procedures and with them established a laboratory at the University of Indiana. He supp

Explain about blood pressure, Explain about Blood pressure Blood press...

Explain about Blood pressure Blood pressure is explained as the force exerted by the blood against the walls of the arteries. Blood pressure (BP) can be described as the fo

Occurrence of earthquake, Among the different natural hazards, earthquakes ...

Among the different natural hazards, earthquakes happen to be the most feared and dangerous because of their sudden impact and the devastation they cause in a matter of few seconds

Give the genotypes, Achondroplasia is an autosomal dominant disorder associ...

Achondroplasia is an autosomal dominant disorder associated with a gene on chromosome 4. Sickle cell anemia is due to a gene on chromosome 11. A man and a woman with achondroplasia

#title.zoology., #question.why obelia is considered of special interest in ...

#question.why obelia is considered of special interest in zoology.

Deficiency diseases-copper deficiency, Deficiency of vitamin -A (hypovitami...

Deficiency of vitamin -A (hypovitaminosis-A) Vitamin A deficiency develops due to insufficient supply of the vitamin or its defective absorption from alimentary tract. The defi

Biology of Plants Assignment, I have a six page assignment, which involves ...

I have a six page assignment, which involves barely any writing, just labeling some plant structures etc. Can someone do this?

Explain briefly about vitamin B12, Vitamin B 12 (Cyanocobalamin) Vitam...

Vitamin B 12 (Cyanocobalamin) Vitamin B 12 refers to a group of Cobalt-containing corrinoids known as cobalamins. It is also called antipernicious- anemia factor, extrinsic f

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