NEET2006ZoologyChemical Coordination and IntegrationActual
Tadpoles of frog can be made to grow as giant sized tadpoles, if they are
Options
- Aadministered antithyroid substance like thiourea
- Badministered large amounts of thyroxine
- Creared on a diet rich in egg yolk
- Dreared on a diet rich in both egg yolk and glucose.
Correct answer
A. administered antithyroid substance like thiourea
Step-by-step solution
Thyroxine, the principal hormone, of thyroid gland, is required for tissue differentiation and metamorphosis (the rapid transformation from the larval to the adult form) in amphibians. Thyroxine triggers a response from the hypothalamus, (probably by a genetic mechanism) followed by the production and release of TSH (Thyroid stimulating hormone), thus metamorphosis begins and tadpoles metamorphose into frogs. Thiourea is an organic compound of carbon, nitrogen, sulphur and hydrogen, with the formula CSN ₂ H ₄ or (