Hello. Please help, I'm a little confused. I'm aware the x and y genes determine whether someone is male or female but which way around is it? Is it: xx=male xy=female ...or... xy=female xx=male I'm also aware half genetic properties are from the father and half are from the mother but are all genetic strands on an x or y gene? I.e. are there only two strands (xx or xy) that contain all genetics material for the being. Thanks for your time. I look forward to your replies.
No. The genes are spread across 23 chromosomes. Only one - the 23rd - defines the sex, thus: Please Register or Log in to view the hidden image! The Y chromosome is shorter than the X. The reason for this goes back to prehistoric times. Once upon a time, all creatures were XX only. Some XXs were wise and cautious and spent their time gathering food. But some XXs were stupid daredevils, who spent their time showing off, getting in trouble and generally making a mess of things. One day, a particularly goofy XX was swinging dangerously from the top of a tree, yelling "HEY Y'ALL! LOOK AT ME! LOOK AT ME!" while all the others below rolled their eyes. The goof slipped and fell out, landing hard. The fall busted off a corner of one of their X's, resulting in the first XY. (Not preventing them from proudly sporting their new cast like it was a trophy.) To this day, XYs still act like stupid goofs, showing off and getting themselves killed, while the XXs roll their eyes and go about their business. Thus endeth the lesson.
No. The sperm contains half of the chromosomes - each sperm is either X or Y. So, upon insemination, an egg will contain one of the female's Xs plus the male's X or Y. So the four possibilities are: Mom provides X1, dad provides Y: boy Mom provides X1, dad provides X: girl Mom provides X2, dad provides Y: boy Mom provides X2, dad provides X: girl
If I remember well that part of my education: A woman's vagina is a caustic acidic inhospitable place for a poor sperm. Y sperm are faster(and die younger), while X sperm are sturdier(and live longer). Orgasm makes the vagina more alkaline & less inhospitable, giving the edge to y sperm. Sex at the time of ovulation gives the edge to y sperm, while sex 3 days prior to ovulation gives the edge to x sperm. See Shettles' work on the subject. .................. 'tis a race between millions of individuals and only one can win the egg. unless, of course, the fsh has stimulated multiple eggs as is more common in women in their 30s. According to the CDC, the incidence of twinning has increased from one in 53 live births in 1980 to one in 31 live births in 2008. This may be the result of more women starting families in their 30s when they are more likely to drop 2 eggs?
You should be able to work out whether this is likely to be true yourself. Think about it. When you look at the world, do you see three times as many women as men? Because that's what your xx:xx:xx:xy is saying there would be, if it were true.
Your mama's been lying to you. Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image!
Mamma's been dead these past 16 years. Her ashes are in an urn on a shelf in my brother's living room. Maybe, he's even kinkier than am I. Though maybe inhospitable for some sperm, but I've rather enjoyed my visits there.
