Fertilization is the process in which a male gamete (sperm) and a female gamete (egg) combine to form a zygote, marking the beginning of a new organism’s development.

The gestation period is the length of time between fertilization and birth in mammals, during which the embryo develops into a fetus.

The placenta is an organ that provides nutrients, oxygen, and removes waste products between the mother and the developing fetus during pregnancy. It also produces hormones necessary for maintaining pregnancy.