females

[admiral_ju00]

ONLY ONE OF THE X CHROMOSOMES DOES ANYTHING.

 

In males Only.

Skye was talking about the female X chromosome in FEMALE.

And stop using the blasted Caps, they don't make your point across any more easier or intelligent.

[ydoaPs]

wow, it is transmitted by females. whoopedy do.

[ydoaPs]

no, in females too. they only use 1 x chromosome.

[Skye]

X chromosome inactivation isn't complete, many genes on the inactivated chromosome are still active. Importantly, genes which correspond to defective genes on the active chomosome are always activated.

[admiral_ju00]

I guess you've never heard of the term Co-Dominant (genes) either.

[ydoaPs]

X chromosome inactivation isn't complete, many genes on the inactivated chromosome are still active. Importantly, genes which correspond to defective genes on the active chomosome are always activated.

 

 

really? well, at Genetic Conference 2004, they said it was the whole chromosome.

 

yes i have heard of codominant genes. it was early last semester.

[Skye]

I'd take a stick to them, it's been known for as long as we've known about the X chromosome silencing that some genes aren't deactivated. It's still something that's being researched though and new stuff is being found out, about how it actually works.

[ydoaPs]

link please.

 

go ahead and take a stick to them. i would tell you who "they" are, but i do not remember. i wasn't interested in genetics or biology in any way so i didn't care. if it were up to me, i wouldn't have even been there. i would have gladly went to Strings instead.

[Skye]

http://www.pnas.org/cgi/content/abstract/96/13/7364

[ydoaPs]

are the active genes more than those of the y chromosome?

[admiral_ju00]

There are only very few genes on the Y that actually code for anything.

[ydoaPs]

that doesn't answer the question.

 

"junk" DNA does stuff, no one know what it is, but when it is removed, the results aren't pretty.

[Skye]

Well that's a complicated question because I'm not sure if there's a set number of active genes on the X chromosome. The link above showed that genes can be inactivated in some cells, but active in others. So the actual number might vary a bit. But I think something like 30 odd genes usually resist silening. There are 28 proteins encoded for by the Y chromosome, but more actual genes, duplicates and stuff.

[admiral_ju00]

I've read somewhere that in the Y, only about 21 active genes have been identified, and some of those were repeats anyway.

 

That kind of a frequency is rather ultra low, since the Y has 50mil nucleotides.

[Arg]

that doesn't answer the question.

 

"junk" DNA does stuff' date=' no one know what it is, but when it is removed, the results aren't pretty.[/quote']

What it "does" is take up space, act as protection against mutations, etc. And sure, if you remove it, things won't work properly; the stereochemistry of various biological reactions hinge upon everything being a certain way, and that way includes the junk being there.

 

"Junk" DNA, by definition, doesn't specifically code for anything.

[Firedragon52]

I find it funny, yourdadonapogos, that you would think the Y chromosome is the one with all the diseases. If you look at this website:

 

http://www.ncbi.nlm.nih.gov/disease/chr21-Y.html

 

...you will what I mean. Look at all the diseases that can be caused by defects in the X chromosome.

[Cap'n Refsmmat]

He tends to ignore everything people say, and just restate his opinion.

[ydoaPs]

I find it funny' date=' yourdadonapogos, that you would think the Y chromosome is the one with all the diseases. If you look at this website:

 

http://www.ncbi.nlm.nih.gov/disease/chr21-Y.html

 

...you will what I mean. Look at all the diseases that can be caused by defects in the X chromosome.[/quote']

 

ok, FOR THE LAST TIME, learn how to read. i never said the y chromosome had all the diseases, in fact, i said the opposite.

[Cap'n Refsmmat]

You never stated that directly.

[ydoaPs]

yea i did. it may have been deleted, but i said it.

[Firedragon52]

Well, if the post where you stated this got deleted, how did you intend for me to "learn how to read" it?

[Chem-Maniac]

Females have two X chromosomes, which is advantage because it prevents them suffering from diseases caused by a recessive gene on the X chromosome.

 

Yeah, that's the only advantage they have...

[Firedragon52]

Yeah, that's the only advantage they have...

Not necessarily true. The lack of Testosterone pumping through their bodies also enables them to live longer.

 

Women also have an advantage of an enhanced immune system, at least until menopause, because of their production of the estrogen hormone estradiol:

http://home.tiac.net/~cri/1997/biosex.html

[Frostrunner]

The So called X inactivation is only for genes that if made twice as much are harmful. The chromatin around the inactivated chromosome is wound tighter and thus it is harder to unwind and activate the genes on it. Females need two recessive alleles while a male only has one allele, thus females are half as likely to get a recessive genetic disorder. If it makes y ou feel better they are twice as likely to get a Dominant allele disorder (these mainly appear in incest cases due to genetic pressure in normal breading). And as far as the whole absence of Y causing maleness, it is that way with bees (XX=queen female, X= worker, XY= drone) but not humans. Actually there are a couple of genes that cause the maleness cascade. There is called fragile X disorder where a person will be XX and not be fully female. It is like having one broken X that can't get it's act together, the person looks like a female except for some sexing problems and hormones can help this. Humans are female by defalt. A person will become a female in development but it is the inclusion of male hormones Testosterone ect. that cause the maleness to occour. Testosterone is actually made from excess estrogen.

[Skye]

Females need two recessive alleles while a male only has one allele, thus females are half as likely to get a recessive genetic disorder.

The probability of receiving two recessive alleles would be the probability of receiving one squared. Eg., if the probability to receive a particular allele was 0.01 (one in a hundred) then to receive two of these alleles it would be 0.01 x 0.01 = 0.0001 (one in ten thousand).

And as far as the whole absence of Y causing maleness, it is that way with bees (XX=queen female, X= worker, XY= drone) but not humans.

All the female bees are produced from fertilised eggs, the males from unfertilised eggs. So there are no sex chromosomes, but rather the females are diploid while males are haploid. The way the queens are reared is what stimulates their development into queens.

Testosterone is actually made from excess estrogen.

Are you sure about that? I believe that all the androgens (including testosterone) are derived from progesterone, and the estogens are then derived from these.