After several miles of running and sprinting in intervals, the runner’s muscles ache and feel fatigued. which is the best explanation for what has occurred?
a. the runner's muscles have accumulated lactic acid.
b. the runner’s body has failed to perform cellular respiration.
c. the runner’s cells are relying completely on aerobic respiration.
d. the runner’s muscles have accumulated carbon dioxide.

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.