Name the three main regions of the human sperm, and briefly mention the function of each.

Name the following :

(i) Three accessory glands of human male reproductive system.

(ii) Two hormones secreted from placenta.

(iii) Two types of twins.

(iv) Two layers of the wall of uterus.

How are carbon dioxide and urea, excreted by the foetus, removed?

Write one sentence each using the following terms pertaining to reproduction in humans.

(i) Gestation

(ii) 280 days

(iii) Head first

(iv) Placenta

(v) After-birth

(vi) Tied and cut