PL HELPPP CANT GET WRONG PL HEL Which of the following is NOT an example of natural selection?

A. Plants with thorns are less likely to be eaten by herbivores than other members of the same species that lack thorns.

B. Bacterial populations in hospitals develop resistance to drugs used to combat infection by them.

C. Scientists breed cows that give greater amounts of milk than their ancestors.

D. Fruit fly larvae with an enzyme to break down alcohol are better able to feed on fermenting fruit than those that lack the enzyme.

Scientists are conducting a study on the effectiveness of a new drug on memory loss. they are giving some of the test subjects the new drug to find out if it improves their long-term memory. which are possible limitations of this study? check all that apply. a) test subjects may want to participate in additional experiments. b) test subjects may think they should be paid more. c) test subjects may get bored and want to quit early. d) test subjects may have to travel during the experiment. e) test subjects may have full-time jobs. this is multiple choice. you for the !