The development of both is controlled by sex hormones produced by the body after the initial fetal stage where the presence or absence of the Y-chromosome and/or the SRY gene determine development.
Male primary sex characteristics are the penis, the scrotum and the ability to ejaculate when matured.
Female primary sex characteristics are the vulva, vagina, uterus, fallopian tubes, cervix, and the ability to give birth and menstruate when matured.
[1] Hormones that express sexual differentiation in humans include: The following table lists the typical sexual characteristics in humans (even though some of these can also appear in other animals as well): In invertebrates and plants, hermaphrodites (which have both male and female reproductive organs either at the same time or during their life cycle) are common, and in many cases, the norm.
In other varieties of multicellular life (e.g. the fungi division, Basidiomycota), sexual characteristics can be much more complex, and may involve many more than two sexes.