Question

Identify development stage and place of occurrence.

• A. Blastocyst, uterine wall
• B. $8$-celled morula, starting point of fallopian tube
• C. Late morula, middle part of fallopian tube
• D. Blastula, end part of fallopian tube

Answer 1

The correct option is A Blastocyst, uterine wall

Zygote moves towards uterus and form blastomeres (2,4,8,16 daughter cells) and then morula (8-16 blastomeres) stage turns into the blastocyst.

Blastomeres in blastocyst arrange into an outer layer trophoblast and an inner group of cells attached to trophoblast.

Blastocyst gets embedded in the endometrium of the uterus (implantation). Uterine cells rapidly divide and cover the blastocyst.

so, the correct option is 'Blastocyst, uterine wall'.