Comment by throwawaymaths
3 days ago
100% of sperm dna comes from father.
but each chromosome could be "grandfathers" or "grandmothers", and usually those chromosomes have one or two crossover events, so, the chromosome goes FFFFFFFFMM for example. (where F = grandfather and M = grandmother)
I assumed F = Frances and M = Michael, my paternal grandparent's names, so thanks for the clarification.
Does that mean gendering a baby is more determined by factors on the father's side?
Whats interesting to me is that along with the autosomes (chr1-22) the sperm contributes either an X or Y sex chromosome. The X chromosome is large and carries a lot of important genes. The Y chromosome on the other-hand is much smaller and carries very few functional genes (primarily just SRY).
So If you think about it girls get ~5% more genetic material from their father than boys.
2.5% (but not really, also remember the chromosomes have different sizes).
this is probably why distribution of traits in men has fatter tails than in women.
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Yes. Sperm cells are haploid. If the sperm that fertilizes the egg has an X chromosome, the baby will be female. If it has a Y chromosome, the baby will be male.
There are rare exceptions for genetic disorders relating to sex development, but generally speaking the above is true.
I never explored this scientifically but I have this hunch that a man with more sisters than brothers will tend to have more daughters than sons
It's a common idea a with some decently strong evidence it's false, https://www.cnn.com/2020/02/18/health/boys-girls-run-in-fami...
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