Question

Given are diagrams showing the different stages in the process of fertilization of an egg in the human female reproductive tract.
Study the diagrams and answer the question.
Draw a neat, labelled diagram of a mature human sperm.

Answer 1

Reproduction is an important phenomena through which a living being can maintain their number of offspring. A man’s sperm fertilizes the egg. A fertilized egg in a female takes around four to five days to go to the uterus from the uterine tube. There are various steps involved in the process of human fertilization.

Complete answer:

Sperm is also called the spermatozoa which is the male reproductive cell. They are produced in the testes. Fertilization is the fusion of the sperm with an egg. The resultant form a diploid zygote. A mature sperm consists of the acrosome, head, midpiece and the tail part. Each of them are explained below.

Head: This region contains DNA which then combines with the egg’s DNA to further create a new human being. It has an acrosome at its tip and the midpiece part.

Acrosome: It has digestive enzymes like the hyaluronidase and acrosin which can efficiently break down the outer membrane of the ovum which is the zona pellucida layer. By this, the sperm cell can join with the haploid nucleus in the ovum.

Midpiece: This region has mitochondria which is very essential for the supplementation of energy which further helps the tail to give motion.

Tail: It is also known as flagellum. It gives the sperm motility to swim to the egg cell and further fertilize it.

Additional information:
For the fertilization process, there are four stages:
1. Sperm preparation
2. Sperm-egg recognition and binding
3. Fusion of sperm and egg
4. Fusion of sperm and egg pronuclei and zygote activation.

Note: Fertilization can happen both internally and externally depending on the living organism. External fertilization takes place outside the body where sperms and eggs are released outside in the environment. So the fertilization takes place outside the body in such cases. It is commonly seen in fishes and amphibians. The internal fertilization takes place within the body of the female. It includes oviparity where eggs are laid outside the female body, ovoviviparity where egg is contained within the female and viviparity where development occurs within the female followed by birth as seen in humans.