| I: | Secondary oocyte is fertilized by the sperm. |
| II: | At fertilization, the secondary oocyte completes Meiosis-II |
| (i) | Relaxin is secreted by the ovary in the later phase of pregnancy. |
| (ii) | Inner cell mass differentiates into ectoderm and endoderm just before implantation. |
| (iii) | Implantation leads to pregnancy. |
| (iv) | Embryo with 8 to 16 blastomeres is called morula. |
| Assertion(A): | Holoblastic cleavage with almost equal sized blastomeres is a characteristics of placental animals. |
| Reason(R): | Eggs of most mammals including humans are of centrolecithal type. |
| 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. | Both (A) and (R) are false. |
| Assertion (A): | All copulations do not lead to fertilisation and pregnancy. |
| Reason (R): | Fertilisation can occur only if the ovum and sperms are transported simultaneously to ampullary isthmic junction. |
| 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. | Both (A) and (R) are False. |