What ensures that only one sperm can fertilize the ovum?
1. Corona Radiata
2. Ground substance around ovum
3. Zona pellucida
4. Acrosome
In humans, the sex of the baby is determined:
1. | At the time of fertilization and by the father |
2. | At the time of fertilization and by the mother |
3. | At the time of implantation and by the father |
4. | At the time of implantation and by the mother |