Question

The glycoprotein fertilizin is secreted by:
A. Ovum
B. Ovary
C. Sperm
D. Testis

Answer 1

Hint: The fertilizin is a chemical which is composed of glycoprotein. The glycoprotein is composed of monosaccharides and amino acids. The fertilizin is found on the plasma membrane of the ovum.

Complete Answer:
- The egg secretes a chemical called fertilizin which is made of glycoprotein. The sperm has a protein called antifertilizin on its surface.
- There is an interaction between the fertilizin and antifertilizin. This interaction helps the sperms stick to the egg surface.
- The antifertilizin is present on the sperm surface. Fertilizin is secreted from the upper most layer of the egg.
- The fertilizin attracts the sperm for fertilization. Fertilizin is found on the membrane of ovum.
- Fertilizin plays a primary role in fertilization. The fertilizin- antifertilizin reaction makes a path for sperm to reach the surface of the ovum.
- The adhesion of the spermatozoon to the egg surface is due to the presence of fertilizing molecules.

So the correct answer is- the fertilizin is secreted by ovum.

Note: The process of fusion of the egg and sperm is called fertilization. Union results in the formation of zygote. A chemical substance called fertilizin is secreted by the ovum. The fertilizin has a number of spermophillic sites. When the sperm reaches the ovum in the oviduct antifertilizin is released by the sperm. The fertilizin – antifertilizin reaction is similar to that of antigen-antibody reaction.