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.
State the purpose of a neuropsychological screening The purpose of a neuropsychological screening examination is to determine if there is reasonable evidence, beyond initial cl
Explain the Criteria for Assessment of Vitamin Status? Vitamin E is assessed by determining the plasma lipid fraction levels. 0.8 mg of total tocopherol/g total plasma lipids i
how does cockroach respire
Explain Continuous Murmurs and their characterstic in details? These murmurs are continuous throughout systole and diastole. It is due to continuous blood flow in the same dire
Mr. Smith read that cholesterol was bad for his health so he eliminated all foods and food products containing this molecule. He later found that his cholesterol level dropped only
Explain the properties or characteristics of dietary fibre? Significant properties / characteristics of dietary fibre that affects its role are: 1) Solubility in water 2)
What is cloning? Cloning is the making of an organism genetically the same to another by means of genetic engineering. The basis of cloning is the nucleus transplantation ma
Enumerate the Number of converging developments These include: 1) A better definition of the unique developmental concepts that are applicable to infants and young children,
Tetrasporic Embryo Sacs In this group neither of the meiotic divisions is accompanied by wall formation so that at the end of meiosis all the four haploid nuclei remain in a
In humans, starch digestion begins in the buccal cavity, but stops in the stomach .Why?
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