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Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. [1] [2] Sex determination is often distinct from sex differentiation; sex determination is the designation for the development stage towards either male or female, while sex differentiation is the pathway towards the development of the phenotype.
The embryo and subsequent early fetus appear to be sexually indifferent, looking neither like a male or a female. Over the next several weeks, hormones are produced that cause undifferentiated tissue to transform into either male or female reproductive organs. This process is called sexual differentiation.
During puberty, a male's erect penis becomes capable of ejaculating semen and impregnating a female. [26] [27] A male's first ejaculation is an important milestone in his development. [28] On average, a male's first ejaculation occurs at age 13. [29] Ejaculation sometimes occurs during sleep; this phenomenon is known as a nocturnal emission. [25]
Development of external genitalia. A: common development. C, E: male development. B, D, F: female development. The following developments occur in both males and females, although a difference in the development between the sexes already can be seen:
The human brain. Differences in male and female brain size are relative to body size. [83] Early research into the differences between male and female brains showed that male brains are, on average, larger than female brains. This research was frequently cited to support the assertion that women are less intelligent than men.
However, women are not physiologically the same as men — marked most plainly with the onset of menstruation at female puberty and two X chromosomes — and thus have often been given incomplete ...
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: estrogens such as estradiol
Multiple women's golfers came forward to praise and celebrate the LPGA's rule change on Wednesday that bars post-pubescent males from competing against females in pro competition.. The ...