It depends. Are you talking about humans? 8D
Humans use internal fertilization but the disadvantages in external fertilization is that a small number of eggs survive.
One disadvantage of external fertilization is that numerous gametes will not survive. Another disadvantage is that the offspring are not protected, which could lead to their death.
They Have Internal Fertilization
In some species there is external fertilization. In other species there is live birth. Live birth requires internal fertilization.
external fertilization is external
External fertilization and development
external fertilization
Salmon use external fertilization
Clams utilize external fertilization.
External Fertilization
cheese
they use external fertilization.
Salmon use external fertilization