Question

Write about membrane fusion occurring during fertilisation.

Answer 1

Fertilization:

1. It is the fusion of male and female gametes that leads to the formation of a zygote.
2. The zygote divides to form an embryo that grows up to become a new individual.
3. Fertilization is the initial step in the process of the development of a new organism.

Membrane fusion during fertilization:

1. Membrane fusion is among one the steps that take place to facilitate fertilization when spermatozoa come in contact with an oocyte.
2. First, the zona pellucida is penetrated, and then the attachment to the vitelline membrane occurs.
3. This attachment is done by the equatorial part of the head of the sperm.
4. The part of the membrane of the sperm that combines with the vitelline membrane, thus pouring the contents of the chromosome into the oocyte.
5. This penetration causes the ovum to complete meiotic division and delivers the first or/and second polar body.
6. At the same time, haploid chromosomes from the female pronucleus.
7. The male chromatin goes through a process of decondensation before it forms the male pronucleus.
8. Decondensation is helped by the components of the ovum cytoplasm.
9. Consequently, both the pronuclei approximate each other, dissolving the pronucleus envelope.
10. The chromosomes then combine forming the diploid cell.
11. This phenomenon is known as syngamy, which indicates successful fertilization. As a result, the fertilized oocyte becomes a zygote.