Admission Test GMAT 問題集 練習問題・模擬試験｜日本語版＆英語版対応

サンプル問題 1： Parasitic wasps propagate by injecting their eggs into a caterpillar that then becomes paralyzed as the eggs inside develop into wasp larvae. The wasp larvae kill the caterpillar host as they feed on it, form cocoons, and finally develop into wasps. In attempting to discover how such wasps detect the presence of the caterpillar hosts that are so critical to the wasps' propagation, researchers have uncovered an intriguing defense mechanism developed by the plants on which the caterpillars feed. When chewed on, many plants release volatile compounds from both damaged and undamaged tissues. When these compounds are toxic to the insects that feed on the plants, they can help defend the plants from such attacks. However, the plants on which the wasps' caterpillar hosts feed have evolved an even more complex defense: the caterpillar-infested plants appear to release volatile chemicals that attract parasitic wasps, which then prey on the caterpillars. Scientists originally suspected that the wasps were attracted by an odor, reminiscent of cut grass, that is released as the caterpillar feeds, but a recent study suggests that a different set of volatile attractants is involved. In this study, when researchers used a razor blade to mimic caterpillar damage on the leaves, only grassy odors were emitted, not the volatile compounds that attracted wasps. However, when oral secretions from the caterpillars were applied to these damaged leaves, the leaves released the wasp attractants several hours later. Further tests revealed that oral secretions placed on the razor-damaged leaves stimulated the release of such attractants, making the plants as attractive to wasps as plants that had suffered actual caterpillar damage. These results suggest that chemicals from the caterpillar must be present for these attractants to be released and that unlike the grassy scent, which emanates only as the caterpillar feeds on the plant, the wasp attractants are produced several hours after the attack and persist for several hours, perhaps days. Researchers have launched additional studies to determine whether the wasps' capacity to prey on caterpillars can be enhanced to the extent that the wasps could be used as a natural pesticide to "police" plants and protect them from crop-destroying caterpillars. The author implies that if, in the experiment described in the second paragraph, the parasitic wasps had been drawn to the plants after they had been damaged by a razor blade but without application of oral secretions from the caterpillar, then scientists would likely have concluded which of the following? Wasps are attracted to the plants by the grassy odor released as the caterpillars feed on the plants' leaves.

• A: Wasps are attracted to the plants by volatile compounds released by the caterpillars as they digest the plant leaves that they consume.
• B: Wasps are attracted to the plants by volatile compounds released several hours after the caterpillars first begin consuming the plants' leaves.
• C: Wasps are attracted to the plants by volatile compounds released by the caterpillars rather than by odors created by the damage the caterpillars inflict on the plants' leaves.
• D: Wasps are more attracted to plants that have been infested by large numbers of caterpillars than to plants infested by relatively few caterpillars.