Does mutation always carry beneficial genetic variations in an organism

Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human x chromosome. the patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. they rarely live past their twenties. how likely is it for a woman to have this condition? a) women can never have this condition.b) one-fourth of the daughters of an affected man would have this condition.c) one-half of the daughters of an affected father and a carrier mother could have this condition.d) only if a woman is xxx could she have this condition.

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above

Which if the following best describes why invertebrates isn’t considered a scientifically valid word when classifying animals