How is the equal genetic contribution of male and female parents ensured in the progeny?

Explanation

In sexual reproduction, both the male and the female parents produce their respective gametes that contain just half the number of chromosomes of the parental cell.
The male gamete fuses with a female gamete to form a zygote which develops into the organism of that species. The fusion of gametes not only restores the original number of chromosomes but also ensures equal genetic contribution of both the parents.