Re: What physical traits are associated with the X chromosome?

    It is hard to say. Some of the differences you mentioned, such as his 
height and build, are determined by tens or even humdreds of genes. 
Some of that possibly came from your mom but, but i would need blood 
samples from every one in your family and a few weeks to tell you exactly. 
As for male pattern baldness, it does come from the mother usually because 
it on the x-chromosome. you see, when there are two x-chromosomes then it is 
possible for one to carry it and the other to not. so yes, your 
observation is correct. Since the dad wouldnt give his x-chromosome if it 
was a boy, then it would not matter if he was bald or not. One final note. 
your brother might have developed his at an early age but just because you 
havent yet does not mean you are 100% in the clear.

Admin note:  Although baldness is linked to the X-chromosome, there may be other 
factors, such as hormonal levels, that are determined by genes on the other 
chromosomes. So it's difficult to say without extensive genetic analysis of you 
and your parents where your baldness or other traits came from, because most are 
determined by several genes spread across the genome, on several chromosomes.