|MadSci Network: Genetics|
Actually the fact that male pattern baldness is a result of a gene past on from the mother has been known well before the big push for the human genome project. Also, male pattern baldness is NOT a dominant autosomal gene. In fact it is a recessive gene on the X chromosome (sex chromosome). If you are a male you have one X chromosome and one Y chromosome. Thus, for males, if you have one X chromosome and the recessive gene on that X chromosome you will have pattern baldness (or whatever recessive trait). Females can have pattern baldness as well but they would need recessive alleles (alternate form of a gene)on both of their X chromosomes (again females are XX and males are XY,) this is why baldness in women is rare. Females at least have that extra X to save them from a recessive allele on the other chromosome. If you remember each parent donates one sex chromosome to their offspring. Thus if you are a male we KNOW the Y chromosome came from your father (because in humans it is the sperm from the male that determins the sex of the offspring - males make both X and Y carrying sperm)and the X came from your mother. The allele for pattern baldness is carried on the X chromosome that means you would inherit pattern baldness from your mother. Below is a few links that explain what I said in a variety of ways. I hope they help. http://nj.essortment.com/malepatternbal_rcad.htm http://school.discovery.com/homeworkhelp/worldbook/atozscience/b/043320.htm l http://pc65.frontier.osrhe.edu/hs/science/bktype.htm
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