The essential features of human reproduction

• Formation of a [blank_start]placenta[blank_end] and maintenance of the unborn child during the entire period of gestation.

• [blank_start]Implantation[blank_end] of the blastocyst, the early embryo developed from the fertilized ovum, in the wall of the uterus.

• [blank_start]Suckling and care[blank_end] of the child, with an eventual return of the maternal organs to virtually their original state

• [blank_start]Birth[blank_end] of the child and expulsion of the placenta.

• Liberation of an [blank_start]ovum[blank_end], or egg, at a specific time in the reproductive cycle.

• [blank_start]Transport[blank_end] of the fertilized ovum to the uterus, or womb.

• Internal [blank_start]fertilization[blank_end] of the ovum by spermatozoa, or sperm cells.