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Name: Mary C. M.
Status: Other
Age: 30s
Location: N/A
Country: N/A
Date: July 2004


Question:
There has been a continuous debate re: WHO ACTUALLY DETERMINES THE SEX OF A CHILD DURING CONCEPTION" as of late and I would like this answered. Biologically most Scientist reflect that a Man determines the sex of a child during conception as they release BOTH chromosomes during the ejaculation process,thus making him the "determinater".

However, in a few months past Parenting Magazine , the article clearly stated "DO NOT BLAME MEN IF YOU HAVE A BOY INSTEAD OF A GIRL"...as it is the women whose eggs actually grip and stick the chromosome to the egg. According to the article, Men release BOTH chromosomes and the Women are actually the GRABBER AND HOLDER OF THE CHROMOSOME CHOSEN.



Replies:
Conception is actually a very complicated process. I'm sure that the author was referring to other factors that can influence conception. But the primary determiner of sex is chromosomal. Males are XY and females are XX. Sex cells, also known as gametes contain only one copy of each chromosome. The male gamete is sperm, the female gamete eggs. So each parent contributes one sex chromosome. A boy is conceived when the father contributes a sperm carrying a Y chromosome. The mother can only give X chromosomes. That sounds simple, but there are many other factors the affect conception. The pH of the vagina can be hostile to sperm, sometimes the mother makes antibodies to the father's sperm. Sometimes the father's sperm can't penetrate the wall of the egg. I heard this year that 2/3-3/4 of all conceptions do not end in pregnancy.

According to the article, Men release BOTH chromosomes and the Women are actually the GRABBER AND HOLDER OF THE CHROMOSOME CHOSEN. I have no idea what the author meant by this. The sperm contains representatives of each chromosome type not just the sex chromosome. Men release both types of sperm (X and Y), but as far as eggs being "grabbers and holders", I'm not sure what that means.

vanhoeck


Interesting idea, but first of all, ova do not grab chromosomes; if they grab anything, they grab the membrane of sperm cells which fuse with the ovum and release their chromosome payload into the ovum. This theory ,therefore, presupposes that there are differences in the membrane of X-chromosome and Y-chromosome carrying sperm cells, and as far as I know, such differences, if they do exist, have not been demonstrated.

Regards, Ron Baker, Ph.D.



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