The blastocyst becomes embedded in the endometrium of the uterus. This is called:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Implantation
Option (1) Lactation — Incorrect. Lactation is the making of milk by the mammary glands after the baby is born.
Option (2) Parturition — Incorrect. Parturition is the delivery of the baby at the end of pregnancy.
Option (3) Implantation — Correct. The blastocyst getting embedded in the endometrium is implantation; pregnancy follows from it.
Option (4) Gestation — Incorrect. Gestation is the whole period of embryonic development in the uterus, about nine months in humans, which comes after implantation.
Note: A similar question was also asked in CUET (UG) 2026 on 15-05-2026 (Slot 1).
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.”
