Choose the incorrect statement from the following:

1. In birds and mammals internal fertilisation takes place. In uterus of the female, the male gamete fuses with the female gamete. Here zygote develops to form an embryo inside the female body.

2. After the birth of a child Colostrum is the first milk form produced by the mammary glands. It is full of nutrients, antibodies and provides immunity boost in the child.

3.Polyspermy is the phenomenon in which an egg meets more than one sperm. In mammals, polyspermy is not prevented by chemical changes. Once the sperm attaches to the zona pellucida layer of the ovum, it brings about physiological changes in the ovum’s membrane and blocks the entry of other sperms.

4.In the human female implantation occurs about seven days after fertilisation.

Only statement ‘c’ is incorrect. Hence option ‘c’ is the correct answer.