Question

Match the following and choose the correct options:

Column I	Column II
A. Trophoblast	i. Embedding of blastocyst in the endometrium
B. Cleavage	ii. Group of cells that would differentiate as embryo
C. Inner cell mass	iii. Outer layer of blastocyst attached to the endometrium
D. Implantation	iv. Mitotic division of zygote

• A. $A-ii,B-i,C-iii,D-iv$
• B. $A-ii,B-iv,C-iii,D-i$
• C. $A-iii,B-i,C-ii,D-iv$
• D. $A-iii,B-iv,C-ii,D-i$

Answer 1

The correct option is D $A-iii,B-iv,C-ii,D-i$

Trophoblast- Outer layer of blastocyst attached to the endometrium

The trophoblast is the outer layer of blastocyst which gets attached to the endometrium and helps in implantation.

Cleavage- Mitotic division of zygote

Zygote formed after fertilization undergoes repeated mitotic divisions called cleavage to form cells known as blastomeres.

Inner cell mass- Group of cells that would differentiate as embryo

Inner cell mass refers to a group of cells attached to the trophoblast on the inner side of the blastocyst. This gets differentiated as the embryo.

Implantation- Embedding of blastocyst in the endometrium

Attachment of the blastocyst to the uterine wall results in the blastocyst getting gradually embedded in the thickened uterine wall. This is known as implantation and takes place after around $6-7$ days of fertilisation.

Final answer:

$b.A-iii,B-iv,C-ii,D-i$