The answer is : crossing over can increase genetic variations during meiosis
Can you provide more details so that I can answer your question properly?
Answer:
The normal pattern for most compounds is that as the temperature of the liquid increases, the density decreases as the molecules spread out from each other. ... The ice structure takes up more volume than the liquid water molecules, hence ice is less dense than liquid water.
Duchenne muyscular dystrophy is caused by a mutation on the X chromosome, so a male gets it from his mother's X, if she is a carrier. The male child gets a Y and no X from his father, so the disease is always transmitted through the X from the mother. If a female gets Duchenne muscular dystrophy she has to have two X chromosomes, one from a carrier mother and another from from an affected father. This is virtually impossible because most males die before childbearing age and there is no way a female child can get an X from a man who does not live long enough to procreate. About eight percent of carrier women do show some muscle weakness, but they do not have the disease.
