Alcohol dehydrogenase (adh) is an enzyme that aids in the decomposition of ethyl alcohol (ch3oh) into nontoxic substances. methyl alcohol acts as a competitive inhibitor of ethyl alcohol by competing for the same active site on adh. when attached to adh, methyl alcohol is converted to formaldehyde, which is toxic in the body. which of the following statements best predicts the effect of increasing the concentration of substrate (ethyl alcohol), while keeping the concentration of the inhibitor (methyl alcohol) constant? a. there will be an increase in formaldehyde because adh activity increases. b. competitive inhibition will be terminated because ethyl alcohol will bind to methyl alcohol and decrease adh activity. c. the peptide bonds in the active site of the enzyme will be denatured, inhibiting the enzyme. d. competitive inhibition will decrease because the proportion of the active sites occupied by substrate will increase.

1. in the wild, male house finches (carpodus mexicanus) vary considerably in the amount of red pigmentation in their head and throat feathers, with colors ranging from pale yellow to bright red. these colors come from carotenoid pigments that are found in the birds' diets; no vertebrates are known to synthesize carotenoid pigments. thus, the brighter red the male's feathers are, the more successful he has been at acquiring the red carotenoid pigment by his food-gathering efforts (all other factors being equal). during breeding season, one should expect female house finches to prefer to mate with males with the brightest red feathers. which of the following is true of this situation? a. alleles that promote more efficient acquisition of carotenoid-containing foods by males should increase over the course of generations. b. alleles that promote more effective deposition of carotenoid pigments in the feathers of males should increase over the course of generations. c. there should be directional selection for bright red feathers in males. d. three of the statements are correct. e) two of the statements are correct.