Brain. Used for identifying a potential mate of the same species and opposite sex.
Testicles. Used for production of sperm (the male gametes).
Ovaries. Used for production and holding of ova (the female gametes).
Fallopian tubes (female). Used to convey a mature ovum from an ovary toward the uterus. Fertilization generally takes place within a fallopian tube.
Uterus (female). Used to support growth of the embryo, and fetus, during pregnancy.