Chemical Coordination and Regulation Question 67
67. Addition of a trace of thyroxine or iodine in water containing tadpoles will
(a) keep them in larval stage
(b) hasten their metamorphosis
(c) slow down their metamorphosis
(d) kill the tadpoles
Show Answer
Answer : b
Hints & Solutions
(b) In 1912, Gudernatsch discovered that metamorphosis in frog’s tadpole is controlled by the thyroxine hormone which has the iodine as the main constituent. If thyroxine or iodine is added in water having tadpoles in it, then it increases the rate of metamorphosis in tadpole.
