Question

Describe the development of a fertilized ovum upto implantation.

Answer 1

Development of fertilized ovum upto implantation:
Fertilisation results in the formation of a diploid zygote. The zygote formed after fertilization undergoes mitosis. Mitosis takes place in the isthmus of the oviduct or the fallopian tube. This process is known as cleavage. The cleavage results in the formation of 2, 4, 8, 16 daughter cells that are called blastomeres. The 8−16 blastomeres is called a morula, which continues to divide to form the blastocyst. The morula moves further into the uterus. The cells in the blastocyst are arranged into an outer trophoblast and an inner cell mass. The trophoblast gets attached to the uterine endometrium, and the process is called implantation. This leads to pregnancy.