Comment Re:24? (Score 1) 194
The "useless" Y chromosome is not useless. In fact, it's very useful. The reason it's seen as bad is because the X and the Y chromosome DO pair up - the Y chromosome is smaller, so it matches up with less of the X chromosome.
The way our genes work (most of you probably remember from HS biology) is that the two genes (one from each chromosome) combine to from a trait. Whether I can roll my tongue or not is a good example. Let's call the ability to roll my tongue "T" and the inability "t". I inherit either a "T" or a "t" from my mother and my father. So, if I have TT or Tt, then I can roll my tongue. If I have tt, then I can't. This means that there are "recessive" traits which are hidden - you can't tell by looking at a Tt that they have the "t" trait because they can do just as much as the TT's.
When dealing with the X-Y pairing, certain loci (locations) on the X chromosome don't have an analog on the Y chromosome. So if there's a recessive trait (think "t") on the X chromosome and it's one of those loci that isn't paired up, then the person won't be able to roll their tongue.
This causes problems in things like male-pattern baldness. Essentially, the recessive trait can get handed down from the mother to son (mother is "Bb" and so on one X chromosome is contained "B" and on the other is "b"). If the son gets the "b" X chromosome, then with no gene on the Y chromosome, they will exhibit male-pattern baldness.
Back to the "useless" part: If this were true for every characteristic on the X chromosome, males would be disease-ridden, pus-infested beings. According to some, that may already be true :> . But it's important that some vital genes exist on the Y chromosome, so it's not quite useless.
John
The way our genes work (most of you probably remember from HS biology) is that the two genes (one from each chromosome) combine to from a trait. Whether I can roll my tongue or not is a good example. Let's call the ability to roll my tongue "T" and the inability "t". I inherit either a "T" or a "t" from my mother and my father. So, if I have TT or Tt, then I can roll my tongue. If I have tt, then I can't. This means that there are "recessive" traits which are hidden - you can't tell by looking at a Tt that they have the "t" trait because they can do just as much as the TT's.
When dealing with the X-Y pairing, certain loci (locations) on the X chromosome don't have an analog on the Y chromosome. So if there's a recessive trait (think "t") on the X chromosome and it's one of those loci that isn't paired up, then the person won't be able to roll their tongue.
This causes problems in things like male-pattern baldness. Essentially, the recessive trait can get handed down from the mother to son (mother is "Bb" and so on one X chromosome is contained "B" and on the other is "b"). If the son gets the "b" X chromosome, then with no gene on the Y chromosome, they will exhibit male-pattern baldness.
Back to the "useless" part: If this were true for every characteristic on the X chromosome, males would be disease-ridden, pus-infested beings. According to some, that may already be true
John
