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

Explanation

Structure of Human sperm:
The spermatozoa consists of a head, middle piece and tail. The sperm head is elongated and formed by the condensation of nucleus.The anterior portion has a cap like structure called acrosome, which contains an enzyme hyaluronidase, that helps the sperm to enter the ovum during fertilization. A short neck connects the head and middle piece, which comprises the centrioles. The middle piece contains the mitochondria which provides energy for the movement of tail. It brings about sperm motility, which is essential for fertilization.

Structure of Ovum:
The mature ovum or egg is spherical in shape, free of yolk and contains abundant cytoplasm and the nucleus. The ovum is surrounded by three membranes. The plasma membrane is surrounded by inner thin zona pellucida and an outer thick corona radiata, which is formed of follicle cells. The membrane forming the surface layer of the ovum is called vitelline membrane. The fluid-filled space between zona pellucida and the surface of the egg is called perivitelline space.