Question

In human female, the blastocyst

• A. Forms placenta even before implantation
• B. Gets implanted into uterus 3 days after ovulation
• C. Gets nutrition from uterine endometrial secretion only after implantation
• D. Gets implanted in endometrium by the trophoblast cells

Answer 1

The correct option is D Gets implanted in endometrium by the trophoblast cells

The placenta begins to develop upon implantation of the blastocyst into the endometrium. The blastocyst gets implanted into uterus 6 days after fertilisation. The blastocyst with the help of trophoblast cells gets implanted in the endometrium of the uterus. Trophoblast is the outer layer of the blastocyte which attaches with the maternal endometrium to form chronic villi of the placenta.

Thus, the correct answer is option D.