Iodine is stored in which of the following glands in the body?

$A$ health disorder that results from the deficiency of thyroxine in adults and is characterised by $(i)$ a low metabolic rate,$(ii)$ an increase in body weight,and $(iii)$ a tendency to retain water in tissues is:

The mineral element whose deficiency causes goiter in humans is ...... .

The primary function of the thyroid gland is to regulate..........

Deaf-mutism can be caused due to $:-$

Thyroxine is secreted by