Human-Reproduction Question 511

Question: Which of the following is the first change that occurs to the zygote after fertilisation?

Options:

A) It divides to form a hollow ball of cells, called the blastocyst.

B) It begins to secrete the hormones.

C) It contacts the endometrial wall of the uterus and becomes buried inside it.

D) It initiates the formation of a placenta.

Show Answer

Answer:

Correct Answer: A

Solution:

[a] The zygote divides mitotically to form 8, 16 daughter cells called blastomeres.

This stage called morula which continues to divide and transforms into blastocyst.