Question

Hormone which is more active than T4 is

• A. T${}_1$
• B. T${}_2$
• C. T${}_3$
• D. T${}_5$

Answer 1

The correct option is C T${}_3$

Thyroxine is secreted from thyroid gland as T4 or tetraiodothyronine. Thyroxine regulates metabolic rate of the body. When thyroxine is secreted as T4 in blood, it is carried to kidneys and liver where it is converted into T3 or triiodothyronine.

T3 is active form of thyroxine. It is more potent than T4 and has a less half life than T4.

So, the correct answer is 'T3'.