Boy And Girl Possibility

[F4T32008]

Usually, the possibility to produce a boy or a girl is the same.. 50%
But, I read my book.. It said that a boy is often produced than a girl... That is happened because the Y chromosome can live longer than X chromosome

Do you think it is true?

[mith]

does the book say why it lives longer?

[MrMistery]

chromosomes aren't alive.

[Tleisha]

Usually, the possibility to produce a boy or a girl is the same.. 50%
But, I read my book.. It said that a boy is often produced than a girl... That is happened because the Y chromosome can live longer than X chromosome

Do you think it is true?

Actually it is postulated that sperm containing an x chromosone (female) can live longer than sperm containing a y chromosone. Supposedly although the female sperm may live longer, the mobility is reduced, while male sperm swim faster. This means that the likelyhood of having a male or female child is also affected by when you attempt to concieve in relation to when you ovulate.
This implies that, for example- if you were to copulate a day or so before you are due to ovulate then by the time ovulation takes place most of the male sperm would be effectively dead, while if the female sperm do infact live longer- they are still swimming.

[F4T32008]

Maybe that's true since the book said that the sperm which contain Y chromosome is more competitive for searching the ovum....

[Morgyn]

I've heard the y-chromosome = fast, x-chromosome = resilient thing before also. Let me know if this is too off-topic but my teacher said the other day that the birth rate of boys during war time is higher than that of girls and when I asked her why she said something about the acidity of the vagina but didn't say anything more.

I have since tried to work out why/how this would happen and I would like to hear what other people think about it:

I thought that during a war women would probably be under more stress than usual. I then thought that stress may cause the body to generally raise the defences (including the acidity in the vagina). This is where the x-chromosome, y-chromosome thing comes in (so it is kinda related) because I wasn't sure how the "male" sperm would be able to survive the higher acidity better than "female" sperm. It would seem that the speed would allow it a better chance, but I'm a bit unsure as to how that would work.

I would appreciate people's opinions, and just let me know (nicely) if this was too off-topic.