What is the number of chromosomes in a human somatic cell?

The number of chromosomes in parents and offspring of a particular species remains constant due to

What changes are observed in the uterus subsequent to implantation of the young embryo?

Give two examples each of the following:
$(a)$ Plants having unisexual flowers
$(b)$ Agents of pollination
$(c)$ Physical changes on puberty that are common to both boys and girls.

How many eggs are produced by one ovary every month in a human female?

Why is the temperature of the scrotal sac $2\,^{\circ}C$ less than the body temperature?