Question

When does the process of cleavage in the fertilised egg of humans start?

• A. Starts in uterus when the zygote attaches itself to the uterus wall
• B. Starts at the blastocyst stage
• C. Starts when egg is in the fallopian tube
• D. Starts at the foetal stage

Answer 1

The correct option is C Starts when egg is in the fallopian tube

The ovum is fertilised by the sperm in the fallopian tube of the female leading to the formation of a zygote. The mitotic division starts as the zygote moves through the isthmus of the oviduct. This division is called cleavage, and it results in 2, 4, 8, and then 16 daughter cells called blastomeres.