Q. 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
Explanation
[Solution from source] The outer trophoblast layer of the blastocyst attaches to the endometrium and the uterine cells then cover it, which is implantation. The placenta forms only after implantation, implantation happens about 7 days after fertilisation (not 3), and the blastocyst is already nourished by uterine secretions before it implants. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.