2011年GMAT考试阅读材料24(附答案)(2)

　　(D) The five major hormones

　　(E) The oligosaccharins

　　3. The passage suggests that which of the following is a function likely to be performed by an oligosaccharin?

　　(A) To stimulate a particular plant cell to become part of a plant’s root system

　　(B) To stimulate the walls of a particular cell to produce other oligosaccharins

　　(C) To activate enzymes that release specific chemical messengers from plant cell walls

　　(D) To duplicate the gene complement in a particular plant cell

　　(E) To produce multiple effects on a particular subsystem of plant cells

　　4. The author mentions specific effects that auxin has on plant development in order to illustrate the

　　(A) point that some of the effects of plant hormones can be harmful

　　(B) way in which hormones are produced by plants

　　(C) hierarchical nature of the functioning of plant hormones

　　(D) differences among the best-known plant hormones

　　(E) concept of pleiotropy as it is exhibited by plant hormones

　　5. According to the passage, which of the following best describes a function performed by oligosaccharins?

　　(A) Regulating the daily functioning of a plant’s cells

　　(B) Interacting with one another to produce different chemicals

　　(C) Releasing specific chemical messengers from a plant’s cell walls

　　(D) Producing the hormones that cause plant cells to differentiate to perform different functions

　　(E) Influencing the development of a plant’s cells by controlling the expression of the cells’ genes

　　6. The passage suggests that, unlike the pleiotropic hormones, oligosaccharins could be used effectively to

　　(A) trace the passage of chemicals through the walls of cells

　　(B) pinpoint functions of other plant hormones

　　(C) artificially control specific aspects of the development of crops

　　(D) alter the complement of genes in the cells of plants

　　(E) alter the effects of the five major hormones on plant development

　　7. The author discusses animal hormones primarily in order to

　　(A) introduce the idea of a hierarchy of hormones

　　(B) explain the effects that auxin has on plant cells

　　(C) contrast the functioning of plant hormones and animals hormones

　　(D) illustrate the way in which particular hormones affect animals

　　(E) explain the distinction between hormones and regulatory molecules

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