引用:
原帖由 wannabe 於 2009-5-18 12:49 PM 發表
九代單傳?
i hate this bullshxt ... and because of this tons of baby girls are killed after or even before born in mainland and unfortunatey this happened once in my mum's side too ... sxxk!
a ...
1 child policy is pretty recent and it's not strictly followed though LOL
It happened in the ancient world as the bad medical system/hygiene, starvation, conscription, etc...
Technology can examine but can't help
Genetic therapy is not that advanced so far.
The chance calculation is quite complicated
Let say, the easiest case, your grandma has a recessive bad gene
1/2 chance to pass that to your mother
1/2 change to pass that to your mother's sister
1/2 change for your mom to pass that to you provided that she has that bad gene
and same for your cousin
If you two marry, 1/4 chance for both bad genes come together and make it apparent.
So, it's (1/2)^6 = 1/64. This is just for one bad gene
If your grandma has quite a few recessive bad gene, you have to calculate for others and the probability will only increase
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本帖最後由 chefung 於 2009-5-18 01:01 PM 編輯 ]