Match List – I with List – II.
| LIST I | LIST II |
| A. Trophoblast | I. Mitotic division of zygote |
| B. Inner cell mass | II. Blastocyst becomes embedded in the endometrium of uterus |
| C. Cleavage | III. Group of cells in the blastocyst attached to trophoblast |
| D. Implantation | IV. Outer layer of blastocyst |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A-IV, B-III, C-I, D-II
A. Trophoblast — this matches IV. Outer layer of blastocyst.
B. Inner cell mass — this matches III. Group of cells in the blastocyst attached to trophoblast.
C. Cleavage — this matches I. Mitotic division of zygote.
D. Implantation — this matches II. Blastocyst becomes embedded in the endometrium of uterus.
NCERT Extract:
Fertilisation and Implantation – “… The blastomeres in the blastocyst are arranged into an outer layer called trophoblast and an inner group of cells attached to trophoblast called the inner cell mass. The trophoblast layer then gets attached to the endometrium and the inner cell mass gets differentiated as the embryo. After attachment, the uterine cells divide rapidly and covers the blastocyst. As a result, the blastocyst becomes embedded in the endometrium of the uterus (Figure 2.11 step H). This is called implantation and it leads to pregnancy.”