Question

What is the correct lineage of a zygote?

(a) Zygote -> Blastomere -> Morula -> Blastocyst

(b) Zygote -> Blastula -> Morula -> Blastocyst

(c) Zygote -> Morula -> Blastomere -> Blastula

(d) Zygote -> Blastocyst -> Blastula -> Blastomere

This question was posed to me in examination.

I want to ask this question from Human Reproduction topic in portion Human Reproduction of Biology – Class 12

Answer 1

Correct choice is (a) Zygote -> Blastomere -> Morula -> Blastocyst

The best I can explain: Zygote undergoes rapid cleavage to form 2, 4, 6, and then 8 blastomeres. They undergo few more rounds of division to form morula. Cells divide further to form a hollow ball called a blastula. This is followed by minor differentiation of cells to produce a blastocyst.