4 ms·
100% of sperm dna comes from father. but each chromosome could be "grandfathers" or "grandmothers", and usually those chromosomes have one or two crossover eve
by throwawaymaths 1y 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)
- sshine 1y agoDoes that mean gendering a baby is more determined by factors on the father's side?
- croisillon 1y agoI 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
- boomboomsubban 1y agoIt'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-families-wellness-scn/ https://www.cnn.com/2020/02/18/health/boys-girls-run-in-fami...
- croisillon 1y agoha :) thank you!
- grumpy-de-sre 1y agoWhats 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.
- throwawaymaths 1y ago2.5% (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.
- grumpy-de-sre 1y agoI couldn't be assed to do the math, not just chromosome size but also number of genes etc, get's tricky to quantify. Fascinating to think about the variability introduced by having only a single copy of the X chromosome. Lot's of interesting genes in there, MAOA/MAOB (primary neurotransmitter breakdown pathways), AR (androgen receptor), OPN1LW/OPN1MW (red green color blindness), G6PD, etc.
- aaaja 1y agoYes. 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.
- IAmBroom 1y agoI assumed F = Frances and M = Michael, my paternal grandparent's names, so thanks for the clarification.