Iodine deficiency in a frog tadpole will lead to:
- AAccelerated metamorphosis
- BDevelopment of a giant frog
- CInhibition of metamorphosis
- DDevelopment of a miniature frog
Show answer and explanation
Correct answer: (c) Inhibition of metamorphosis
Explanation
The change of a tadpole into a frog (metamorphosis) is controlled by thyroxine, the hormone of the thyroid gland. Iodine is an essential part of thyroxine.
If a tadpole lacks iodine, its thyroid cannot make enough thyroxine, so metamorphosis is inhibited: the tadpole stays a tadpole and may keep growing without becoming a frog. On the other hand, adding thyroxine or iodine to the water speeds up metamorphosis.