In ovoviparity the fertilized eggs are retained inside the mother's body to complete development. the young obtain all nourishment from the egg and are fully developed when they hatch and are released from the mother
Step-by-step explanation:
Through evolution the place of zygote formation and maturation has developed accordingly to gain nourishment form the mother and to protect the young ones, the female systems started carrying the zygotes inside their body for a particular period of time . This period is called as the gestation period.