Swollen face,mental dullness,dry skin,and loss of appetite are the characteristics of:

What is Isthmus?

The hormone responsible for metamorphosis in a tadpole is

Read the given statements $:$
$(A)$ Hypothyroidism during pregnancy causes defective development and maturation of the growing baby.
$(B)$ Thyroxine does not require a secondary messenger.
$(C)$ Thyroxine plays a major role in the regulation of Basal Metabolic Rate $(BMR)$.
$(D)$ Hypersecretion of thyroxine could cause immunodeficiency.
How many of the above statements are correct?

$A$ toxic agent present in food which interferes with thyroxine synthesis leads to the development of:

Assertion: The thyroid gland is composed of follicles and stromal tissue.
Reason: Iodine is essential for the normal rate of hormone synthesis in the thyroid.