Question

If thyroid is removed from tadpole, it will

• A. Die soon
• B. Remain tadpole throughout its life
• C. Grows in to giant frog
• D. Grows into dwarf frog

Answer 1

Answer: (B)

Remain tadpole throughout its life

In amphibian metamorphosis, thyroxine ( $T_4$- iodine-containing hormone) produced by the thyroid gland causes apoptosis of the cells of gills, tail, and fins of tadpoles. It plays a major role in the amphibian metamorphosis that transforms the vegetarian aquatic tadpole into a carnivorous terrestrial adult frog, with better neurological, visuospatial, olfactory, and cognitive abilities for hunting, as seen in other predatory animals. Removal of this organ will arrest the development of tadpole.

Thus the correct answer is option B.