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.
explain the cell survival curve
PHASES OF NURSE-PATIENT RELATIONSHIP: Kapoor, Bimla (1994) has listed four phases of nurse patient relationship which are explained below while describing the phases she has
Define the term - Stimulus Stimulus and response characteristics of the tests themselves, as well as of the test instructions, become exceedingly important considerations. In g
# ???? ..
write literature Review on this topic
(a) Bedroom : · Do not place room heaters near any inflammable materials. · Do not use heaters
Biology : Biology may be defined the study of living organisms. It mainly deals with the characteristics of living organisms and their classification. It is also concerned with the
What happens if platelets aren''t present in blood?
Q. Which kind of tissue are the cartilaginous and the osseous tissue? The osseous and the cartilaginous tissues are considered connective tissues since they are tissues in whic
Insulin, insulin syringe and insulin devices Insulin is the hormone used to treat diabetes mellitus. Insulin is given in the form of injection, because the gastro intestinal tr
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd