Question: 171: Given below are two statements: one is labelled as Assertion (A) and other is labelled as Reason (R).
Assertion (A) :
During pregnancy the level of thyroxine is increased in the maternal blood.
Reason (R) :
Pregnancy is characterised by metabolic changes in the mother.
In the light of the above statements, choose the most appropriate answer from the options given below :
(1) Both (A) and (R) are correct and (R) is the correct explanation of (A)
(2) Both (A) and (R) are correct but (R) is not the correct explanation of (A)
(3) (A) is correct but (R) is not correct
(4) (A) is not correct but (R) is correct
Answer: Option (1)
Explanation:
During pregnancy, the mother undergoes several physiological and metabolic changes to support the growth and development of the fetus.
Thyroxine is a thyroid hormone that regulates metabolism, growth, and development of tissues.
The level of thyroxine in maternal blood increases during pregnancy to meet the increased metabolic demands of the mother and the developing fetus.
Pregnancy is indeed characterised by significant metabolic changes, including increased basal metabolic rate.
These metabolic changes stimulate increased secretion of thyroxine.
Therefore, both the Assertion and the Reason are correct,
and the Reason correctly explains the Assertion.