Many intracellular signaling proteins act as switches that toggle from an inactive to an active state. once activated, these signaling proteins can stimulate—or in some cases inhibit—other proteins in the signaling pathway. an interaction that results in stimulation is often depicted by an arrowhead (→), whereas inhibition is indicated by a crossbar (—i). in which of the hypothetical signaling pathways outlined below would activation of the receptor lead to an increase in gene expression?

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.