Class 12th Biology 2017 Set3 Delhi Board Paper Solution
Where in the fallopian tube does fertilization occur in humans? describe the development of a fertilized ovum upto implantation.
The fertilization in humans occur in the ampullary-isthmic junction of the fallopian tubes.
Development of a fertilized ovum upto implantation:
Fertilization results in the formation of diploid zygote. The zygote formed after fertilization undergoes mitosis. Mitosis take 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 daugher cells that are called blastomers. The 8-16 blastomers is called morula, which continues to divide to form the blastocyst. The morula moves further into the uterus. The cell in the blastocyst are arranged into an outer trophoblast and an iner cell mass. The trophoblast gets attached to the uterine endometrium and the process is called implantation. This leads to pregnancy.
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