Describe the process of fertilization, development and birth in human beings.

Ans. 1. The sperms enter through the vaginal passage, travel upwards and reach the oviduct where they may encounter the egg. 

2. As soon as it is fertilized, the egg cell (zygote) begins to divide until it becomes a ball of cells called blastocyst. 

3. The ball then implants itself in the wall of the uterus. 

4. The development of the embryo takes place inside the uterus where the embryo gets all the nutrients and oxygen from its mother’s blood in the oviduct supplied through the umbilical cord. 

5. From nine months onwards, the baby is ready to take birth. It moves down. 6. During birth, the cervix gradually opens and the baby is released through the vagina.