Name two glands present in the skin whose increased activity causes pimples and acne.

What substance is secreted by sebaceous glands?

Name the time period in one’s life when the brain has the greatest capacity for learning.

What name is given to those sexual characteristic in humans:

(a) which are present in babies at birth?

(b) which develop in mature boys and girls?

Name any two glands which function as endocrine glands as well as exocrine glands.