Easy (and this is how it was explained in my college Biology class)
For the first six weeks in the womb, all embryos are female. It is in this time period that nipples develop. The Y chromosome in males doesn't activate the testosterone until about the sixth week of pregnancy.
For the first six weeks in the womb, all embryos are female. It is in this time period that nipples develop. The Y chromosome in males doesn't activate the testosterone until about the sixth week of pregnancy.
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Funny question with a scientific explanation. I will be technical.
All humans begin life in the womb as females. If no Y chromosome is present in the foetus, then the embryo will continue to develop as and be born as a female. If there is a Y chromosome present in the embryo, the male sex hormone testosterone restricts the full development of breasts to just nipples.
All humans are born with potential breasts. In the case of women they are triggered to develop hormonally as a secondary sexual characteristic. Men not only have nipples, but undeveloped breasts. So, that is why men have nipples.
All humans begin life in the womb as females. If no Y chromosome is present in the foetus, then the embryo will continue to develop as and be born as a female. If there is a Y chromosome present in the embryo, the male sex hormone testosterone restricts the full development of breasts to just nipples.
All humans are born with potential breasts. In the case of women they are triggered to develop hormonally as a secondary sexual characteristic. Men not only have nipples, but undeveloped breasts. So, that is why men have nipples.
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The nipples are the pigmented erectile tips of the mammary glands or breasts, and are present in both male and female mammals. Usually conical in shape, nipples can also be everted, flat, or, more rarely, inverted. They are encircled by a pigmented ring called the areola, and surrounded by nerve endings and blood vessels. When stimulated by touch or friction, or through sexual arousal, blood flowing through the vessels causes the nipples to become erect. Although stimulation of the nipples is usually pleasurable, both males and females vary greatly in the degree of sensation they experience. In women, nipples bear the openings of the lactiferous ducts through which milk is secreted when breast-feeding. During pregnancy and lactations, the woman's nipples become enlarged and her areolae darken in colour.
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The DNA that codes for nipples is not on the X and Y chromosome. So that structure is present in both sexes, and is activated through hormones that are ultimately controlled by the presence of X/Y chromosome.
Women have hair follicle that would allow them to grow beard if they were subjected to the proper concentration of testosterone.
Women have hair follicle that would allow them to grow beard if they were subjected to the proper concentration of testosterone.
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Sarcasm: A literary device for identifying the stupid.
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Makes gender reassignment easier.