why is it not possible to get yy chromosomes?

Answer 1

It isn't possible because actually, X and Y are not only sexual chromosomes (i.e. they contain genes that solve several functions besides determining our sex)
Actually, an Y chromosome is not needed strictly for life (there are X only individuals, that's called Turner's syndrome and the affected persons are genetically female, short and fat with a short neck and many physical anomalies)
The X chromosome, however, is much bigger than Y and contains many more genes that are absolutely necessary for life (for example it contains the genes for dystrophine, which is essential for a correct muscular functioning)

Therefore, it IS possible to get YY chromosomes, but you never see people around with YY just because they die before being born

Answer 2

Found the following on a web site - did a copy and paste to here. Very interesting and hope it helps answer your question Question - Is it possible for a person to be born with YY sex chromosomes? Missing the X chromosome completely is lethal to my knowledge. I also know of no cases of live birth to a human with no x chromosomes. XYY is possible and does occur. XYY can be normal although some evidence indicates they are sometimes below normal intellect and sometimes violent. Peter Faletra Ph.D. Office of Science Department of Energy No, the Y chromosome does not have a full complement of genes that the X chromosome contains. An individual must have at least one X chromosome to survive. Steve Sample It is possible for a person to INHERIT two Y chromosomes, but the embryo would fail to thrive and be miscarried. Remember that the X chromosome has many characteristics on it that have nothing to do with gender and that are necessary for life. vanhoeck Just recently it was discovered that the X chromosome has the primary role in sperm production in males. This alters our view of the X-Y chromosome operation. Steve Sample

Answer 3

Question - Is it possible for a person to be born with YY sex
chromosomes?

Missing the X chromosome completely is lethal to my knowledge. I also know
of no cases of live birth to a human with no x chromosomes. XYY is possible
and does occur. XYY can be normal although some evidence indicates they are
sometimes below normal inteelect and sometimes violent.

Peter Faletra Ph.D.
Office of Science
Department of Energy
=========================================================
No, the Y chromosome does not have a full complement of genes that the X
chromosome contains. An individual must have at least one X chromosome to
survive.

Steve Sample
=========================================================
It is possible for a person to INHERIT two Y chromosomes, but the embryo
would fail to thrive and be miscarried. Remember that the X chromosome has
many characteristics on it that have nothing to do with gender and that are
necessary for life.

Answer 4

YY chromosome is supposed to be a super-male chromosome and I doubt such a human would have possibility to duplicate. Thus, this kind of chromosome can't survive in genome. However, there is an XYY polysomy which sometimes makes people taller.
Greater degrees of Y chromosome polysomy (e.g., XYYYY) are very rare. Rarely, males may have more than one extra copy of the Y chromosome in every cell (polysomy Y). The extra genetic material in these cases can lead to skeletal abnormalities, decreased IQ, and delayed development, but the features of these conditions are variable.

Answer 5

I'm not sure if the other people just misunderstood your question - whether or not you could survive that way is irrelevant, because it's impossible to get yy, because sperm only carry x, and eggs are either x or y (and occassionally - very rarely xxy, which results generally in a set of "identical" different-gendered twins). Men do not create a y chromosome, so the only availble chromosomal combinations must contain at least 1 x chromosome.

Answer 6

Fertile women don't have y chromosomes to give the baby (women are supposed to have two X chromosomes). And it still takes a man and a woman's contribution to make a baby. Damage to the x or the y chromosomes, though, seem to produce some pretty startling effects, so I don't think scientists will try to pursue creating a double-y fetus. At least, I hope they don't! Too mad-scientist-y for me!

Answer 7

Whats The yy chromosomes ??

Answer 8

The human Y chromosome is a smidgen of a chromosome and contains virtually no
genes. It only contains those genes necessary for becoming male, the SRY for
example. Sex determination occurs differently in different species and I
cannot say whether all Y chromosomes are so small in all species. But in
humans, the X contains genes that all of need for life-in females there are
two copies of each gene and in males only one (they only have one X) but most
of the genes on the X have nothing to do with sex determination. Examples
include genes for the ability to see color and to make blood clotting
proteins. Whether these same genes are found on all species' X I do not
know,
but I suspect not all of them. So, at least in humans, everyone needs at
least one X. Without one, life is impossible (for humans).

Answer 9

female: XX
male:XY
it is impossible to get YY because there's only one Y available
when the male mate with the female, the most it can get is XY and never YY. get it?

hope it clears some misunderstandings u have(:

Answer 10

A zygote could get them, but it would die. A human needs the X chromosome to live.

And as we know, the Y chromosome is actually a truncated X.