True
S phase -
synthesis phase, during this phase , a cell copies it's DNA
Answer:
b. the usual frequency of blizzards in an area
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.
