Egg Cells (Oocytes): These are the female reproductive cells produced in the ovaries. Each menstrual cycle, a mature egg is released during ovulation and is ready to be fertilized by a sperm cell.
Sperm Cells: These are the male reproductive cells produced in the testes. During ejaculation, millions of sperm are released, and they travel through the female reproductive tract to reach and fertilize the egg.
Embryos: When an egg cell is successfully fertilized by a sperm cell, it becomes an embryo. This fertilized egg then begins to divide and develop, eventually implanting in the uterine wall, where it can grow into a fetus.