Question

............. should be present in the water for metamorphosis of tadpoles.

• A. Chlorine
• B. Carbon
• C. Sulphur
• D. Iodine

Answer 1

Answer: (D)

Iodine

• The tadpoles are generally defined as the stage of the amphibian when they are in the form of a larva, particularly that of the frog and the toad.
• For the metamorphosis of tadpoles, iodine should be present in the water. This is because metamorphosis is brought by thyroxine hormone that requires the presence of iodine for its production by the thyroid gland.
  
• Hence Iodine should be present in the water for the metamorphosis of tadpoles.
• So, the correct answer is 'iodine'.