2007-10-27 08:09:42 · 19 answers · asked by JEH 1 in Science & Mathematics ➔ Biology
Because the foetus is sexless up to a point while it's in the womb.
2007-10-27 08:13:33 · answer #1 · answered by mirrors and smoke 5 · 4⤊ 1⤋
Nature has a tendency to do things in the simplest possible way, and that means having as few changes as possible between men and women.
Humans have 23 pairs of chromosomes, of which 22 pairs are the same in males and females. These are called autosomes.
Only one pair of chromosomes, the sex chromosomes, are different. Men have an X and a Y chromosome and women have two X chromosomes.
In female cells, one of the X chromosomes is always inactive. This means that men and women essentially have the same number of X chromosomes.
Therefore, men have the exact same genetic material as women, with the addition of the extra genes on the Y chromosome. This means that *all* of the differences between men and women must occur because of genes coded on this one chromosome.
Although men technically have all of the biological machinery required to develop breasts and feed babies, it never develops because the presence of the Y chromosome prevents the right hormones from stimulating them at the right time.
The short answer is that men have nipples because all of the genes present in women are also present in men.
2007-10-27 08:30:51 · answer #2 · answered by Anonymous · 1⤊ 0⤋
All embryos start of as female until the 7th week therefore men develop nipples just like women before they start changing and growing male organs.
2007-10-29 06:41:51 · answer #3 · answered by tate_gemma 2 · 1⤊ 0⤋
Initially we all start out as female in the womb, so we all have nipples. The during fetus development, if there is a Y chromosome, then the fetus begins developing as male and the proper hormones for breast development do not develop.
2007-10-27 08:15:38 · answer #4 · answered by Lady Geologist 7 · 3⤊ 0⤋
Because all fetuses start out the same, both sexes get nipples and then there parts form which makes us a certain sex,,,,,,,That didn't make sense but i get me lol
2007-10-27 09:42:01 · answer #5 · answered by DONNA C 1 · 0⤊ 0⤋
I believe it is because men and females all start out the same in the egg and then develop. Thats all I can remember from science!
2007-10-27 08:13:35 · answer #6 · answered by yesbethyes 1 · 1⤊ 0⤋
because we all start off as female in the womb but then one of the X chromosomes changes so instead of XX for female it changes to XY but by the point the nipples have already developed
2007-10-28 12:20:31 · answer #7 · answered by lou 2 · 0⤊ 1⤋
I think the fetus starts of sexless or female and then later testosterone goes in to the baby making them male.
I'm not very good at explaining it sorry.
2007-10-27 08:16:59 · answer #8 · answered by xoɟ ʍous 6 · 1⤊ 0⤋
they have nipples because when they develop in the womb all babies are female to start with.
2007-10-27 08:17:42 · answer #9 · answered by jessie 3 · 2⤊ 0⤋
men used to be women
2015-12-09 03:52:18 · answer #10 · answered by Anonymous · 0⤊ 0⤋