Question

Tadpole is the developing stage of:
1. Snake
2. Butterfly
3. Fish
4. Frog

Answer 1

Correct Answer - Option 4 : Frog

The correct answer is Frog.

• Tadpoles are the young of amphibians particularly of frogs and toads.
• The process by which a tadpole develops into an adult frog is called Metamorphosis.
• A frog lays eggs that become tadpoles in just a few days.
• These tadpoles live underwater and in the next few weeks.
• Hormone thyroxine present in the thyroid gland of the tadpole initiates the process of Metamorphosis.
• Thyroxin hormone produces by the thyroid gland in the presence of Iodine.
• That’s why Iodine should be available in sufficient quantity in the water of the pond.
• If iodine is not available in the diet, then the thyroid may produce an insufficient hormone which will affect the process of metamorphosis. 
• If water is iodine-deficient, in which the frog lays an egg, then tadpoles hatched from these eggs will not grow into adult frogs.