The hormone that controls the basal metabolic rate $(BMR)$ in our body is secreted by:

The thyroid gland is composed of $A$ lobes which are located on either side of the $B$. The lobes are interconnected with a thin flap of connective tissue called $C$. Select the correct combination for $A, B$ and $C$.

Thyroxine is secreted by

Why is $Thyroxine$ considered a hormone and not an enzyme?

Which hormonal deficiency is responsible for the following:
$(a)$ Diabetes mellitus
$(b)$ Goiter
$(c)$ Cretinism.

Given below are two statements: one is labelled as Assertion $(A)$ and the 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: