Sexual differentiation absence of the genes that generate male genitalia do not single-handedly lead to a female brain. The male brain requires more hormones, such as testosterone, in order to properly differentiate. These hormones are released due to a gene expressed during embryonic development. Sexual differentiation Sexual differentiation is the process of development of the differences between males and females from an undifferentiated zygote. As male and female individuals develop from zygotes into fetuses, into infants, children, adolescents, and eventually into adults, sex and gender differences at many levels develop: genes, chromosomes, gonads, hormones, anatomy, and psyche. Sex differences range greatly and
Breast development Breast development Breast development, also known as mammogenesis, is a complex biological process in primates that takes place throughout a female's life. It occurs across several phases, including prenatal development, puberty, and pregnancy. At menopause, breast development ceases and the breasts atrophy. Breast development results in prominent and developed structures on the chest known as breasts in primates, which serve as both a sexual characteristic and as mammary glands. The process is mediated by an assortment of hormones (and growth factors), the most important of which include estrogen, progesterone, prolactin, and growth hormone. The master regulators of breast development are