Answer: Implantation
Step-by-step explanation:
Implantation is a process of attachment of the fertilized diploid cell called as zygote to the wall of the uterus. This step is the initiation of the process of gestation (the period when the zygote attaches itself to the wall of the uterus till the delivery of fully developed fetus). The zygote undergoes cell division and differentiation to form embryo. The embryo receives nutrients and oxygen from the mother to transform into fully developed fetus.