Question

Assertion (A): Implantation occurs when the blastomere stage gets embedded into the thickened wall of uterus.

Reason (R): After implantation, the trophoblast layer forms a special tissue called placenta.

Options

• Both assertion (A) and reason (R) are true, and reason is the correct explanation of assertion.

• Both assertion (A) and reason (R) are true, but reason is not the correct explanation of assertion.

• Assertion (A) is true but reason (R) is false.

• Both assertion (A) and reason (R) are false.

Answer 1

Both assertion (A) and reason (R) are true, but reason is not the correct explanation of assertion.

Explanation:

Even though both sentences are individually correct facts about human reproduction, the reason describes a subsequent development that happens after implantation occurs. It does not explain why or how the blastocyst implants itself into the uterine wall in the first place (which involves factors like blastocyst hatching, hormonal priming by progesterone, and cellular adhesion).