Where does the cleavage starts in the fertilised egg in humans ?

It starts when the egg is in fallopian tube.

The correct answer is Option (2)- It starts when the egg is in fallopian tube.

The correct answer is "It starts when the egg is in fallopian tube." Cleavage, which involves rapid cell division, begins in the fertilized egg (zygote) as it travels down the fallopian tube toward the uterus. This series of mitotic divisions leads to the formation of a multicellular structure called a blastocyst.

The mitotic division starts as the zygote is still in the fallopian tube and moves through the isthmus of the oviduct called cleavage towards the uterus and forms 2, 4, 8, 16 daughter cells called blastomeres.