| Assertion (A): | The blastocyst undergoes implantation in the endometrium shortly after reaching the uterus. |
| Reason (R): | Implantation triggers the release of relaxin, which softens the cervix in preparation for childbirth. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A) |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
| a: | Internal fertilisation takes place in mammals |
| b: | Colostrum contains antibodies and nutrients |
| c: | Polyspermy in mammals is prevented by corona radiata |
| d: | In the human female, implantation occurs almost seven days after fertilisation |