Describe the structure of the human ovum with a neat labelled diagram.

Explanation

(i) The mature ovum or egg is sperical in shape .
(ii) The ovum is almost free of yolk . It contains abundant cytoplasm and the nucleus .
(iii) the ovum is surrounded by three membranes . The plasma membrane is surrouded by inner thin zona pellucida and an outer thick Corona radiata .
(iv ) The corona radiata is formed of follicle cells the membrane forming the surface layer of the ovum is called vitelline memnbrane .

(v) The fluid - filled space between zona pellucida and the surface of the egg is called perivitelline space .