Question 4 - Assertion Reasoning questions (MCQ) - Chapter 8 Class 10 - How do Organisms Reproduce?

Assertion (A): At puberty, in boys, voice begins to crack and thick hair grows on face.

Reason (R): At puberty, there is decreased secretion of testosterone in boys.

Answer:

The various changes which occur in boys at puberty are:  

• Hair grows under armpits and in pubic regions (genital area) between the thighs. 

• Hair also grows on other parts of the body like chest and face (moustache, beard, etc.)

• Body becomes more muscular due to the development of muscles. 

• The voice deepens (or cracks). 

• Chest and shoulders broaden. 
• The penis and testes become larger. 
• The testes start to make sperms. 
• Feelings and sexual drives associated with adulthood begin to develop. 

All these changes in boys are brought about by the male sex hormone 'testosterone’ made in testes.

Thus,

• Assertion is true.
• Reasoning is false.

So, the correct answer is (c).