Answer:
1.It is called mating
2. gamete/Gametes
3.Internal fertilization is the union of an egg and sperm cell during sexual reproduction inside the female body. Internal fertilization, unlike its counterpart, external fertilization, brings more control to the female with reproduction
4.Birds, fish, amphibians, reptiles, insects, coral, sea anemonoes, other related reef creatures such as the sea fan and the sea feather, shellfish, and platypus etc.. undergoes external fertilization.
5.sperm