female:male ratio in K-3 kids
frest001 at MAROON.TC.UMN.EDU
Mon Jan 15 03:42:08 EST 1996
Not sure if this was mentioned yet, but "male" (carrying the Y chromosome)
sperm cells can travel faster than "female" (carrying the x chromosome
which is much bigger than the Y) sperm cells due to the smaller amount of
genetic material in the "male" sperm head!
On Sun, 14 Jan 1996 23:02:22 -0800,
Kimberly Anne Chapman <kchapman at paul.spu.edu> wrote:
>On 11 Jan 1996, Jane Dorweiler wrote:
>> Whether this phenomenon is widespread or not, the first thing that came to mind
>> when I heard this was the fact that it was about 6 years ago or so that I
>> started to hear theories on how to increase the likelihood of conceiving a child
>> of a particular sex by controlling the frequency and/or timing of intercourse
>> relative to ovulation. Perhaps there just happened to be many couples who were
>> trying for a particular sex child based on these methods??
>> Jane Dorweiler ** Regardless of what they say about the
>> Department of Plant Biology ** cat, curiosity is a good thing. It's
>> University of Minnesota ** what makes each and every one of us
>> dorwe001 at maroon.tc.umn.edu ** a scientist!!
>I'd like to have more faith in American couples and discount the
>possibility of people trying for a child of a particular sex. That has
>some very ugly ramifications. But I think Jane Dorweiler is definitely
>onto something regarding the frequency and time of intercourse. We are
>all aware of the significant changes in a woman's body throughout the
>menstrual cycle. In a genetics course I was reminded that one of these
>changes was the fluctuation of the pH of the vagina. I was amazed to
>hear that studies have been done showing that some spermatozoa have a
>higher affinity and functioning capacity in a slightly more acidic
>environment while others do better in a more basic environment.
>Unfortunately I'm unable to recall which sperm cells are which, but I'll
>be contacting the prof who taught the course. In light of this
>information, I would hypothesize that the timing of intercourse in
>conjunction with the current pH of the vagina is what influences which
>sperm cells live to reach the ovum, therefore having a higher probability
>to fertilize it.
> I'd be very interested in feedback. Thanks in advance!!
Joy L. Frestedt
Laboratory Medicine and Pathology
University of Minnesota
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