Question

Explain how fertilization takes place in human beings. (with diagram)

Answer 1

Hint: Fertilization is the process in which fusion of male and female gametes takes place. Fertilization occurs when the sperm cell meets with an egg cell in the fallopian tube and the fertilized egg is called a zygote.

Complete Answer:
- Semen released during the copulation from the penis which is a male reproductive part into the vagina, a female reproductive organ. These movable sperms went into the uterus and finally reached the fallopian tubes.
- The ovum and the sperm are simultaneously transported in the fallopian tubes and when ovum and sperm fuse fertilization take place. Fertilization takes place in the fallopian tubes that connect the ovaries to the uterus.
- When the sperm and ovum come in contact with each other, it induces a change in the ovum’s membrane (zona pellucida) which blocks the entry of the other sperms. It is important that only one sperm fuses with the ovum.
- In the entry of the sperm acrosomal secretions play a vital role. This helps in completing the meiotic division of the secondary oocyte. This secondary meiotic division helps in formation of a second polar body and haploid ovum. Once the fertilization takes place then the newly fertilized egg called zygote (diploid) will form.

Note: Fertilization takes place in the fallopian tubes where the sperm cell and egg cell fuse with each other and thus, forming a zygote (diploid). Zygote will move down the fallopian tube and into the uterus lining and this is called implantation and implantation of zygote is called a blastocyst.