获取方案

dea This question addresses what the information in the passage indicates about plant antiherbivore chemistry—that is, plants’ chemical defenses against herbivore attacks. The second paragraph of the passage cites the views of various scientists regarding the possible role of resin in antiherbivore chemistry; plants could have evolved resin specifically to repel insects. A. Correct. According to the second paragraph, various scientists have suggested that a change in antiherbivore chemistry, here specifically involving resin, could repel insects; alternatively, some insects could have been attracted to resin, feeding more heavily on plants that produced it. Other researchers have suggested that even if resin does not directly repel or attract insects, it may indirectly affect insect-feeding behavior by mediating changes in plants’ antiherbivore chemistry. B. The first paragraph states that plants produce gum in response to bacterial infections. Although this does not rule out the hypothesis that gum also contributes to plants’ antiherbivore chemistry, the passage provides no evidence that it does so. C. According to the passage, a plant’s antiherbivore responses have developed to combat predators, such as insects, that eat plants. The passage provides no evidence that such responses also combat bacterial infections. D. The second paragraph indicates that plant antiherbivore chemistry plays a major role in the discipline of chemical ecology, and chemical ecology concerns itself with coevolution of plants and insects. E. According to the passage, it was in the 1950s that entomologists began discussing resin’s possible role in repelling and attracting insects. The passage does not suggest that this marked the beginning of their study of repellent effects more generally. The correct answer is A.