Question

Read the following and answer from given below:

Cleavage is the series of rapid mitotic divisions in the zygote and forms blastula. The 2, 4, 8, 16 daughter cells are called blastomeres. An embryo with 64 blastomeres is known as a blastocyst and has a blastocoel cavity. Blastocyst gets implanted in the uterine wall and leads to pregnancy.

At which stage of embryonic development does trophectoderm develop?

Options

• Zygote

• Morula

• Blastula

• Gastrula

Answer 1

Blastula

Explanation:

Embryo with 64 cells is called blastula (blastocyst) and has a blastocyst cavity. The blastocyst is composed of an outer envelope of cells called trophoblast and inner cell mass.