Practice Test: Reading Comprehension - 41 | 100 RCs for GMAT PDF Download

The first paragraph introduces COX-2 inhibitors and talks briefly about a 1971 discovery linking aspirin to prostaglandins. Paragraph 2 elaborates on the connections among aspirin, prostaglandins, and the three types of COX enzymes. Paragraph 3 discusses COX-2 inhibitors specifically, both the impetus for creating them and some negative effects. The final paragraph provides caution about the promise of COX-2 inhibitors.

(A) The passage explains the intended benefits behind the development of COX-2 inhibitors, but this is much too narrow to be the main purpose of the passage, particularly when a large part of the passage addresses the negative consequences.
(B) The author does not initiate a “debate.” For a debate, the author must introduce two clear opposing sides. The COX-2 inhibitors were developed to replace the earlier drugs that inhibited both COX-1 and COX-2, but then they were also found to have side effects.
(C) While paragraph 4 states that “Side effects almost always cropped up, even after clinical trials that seemed to indicate none," the author notes this only in the context of explaining the result of COX-2 inhibitors. This is too narrow to be the main purpose of the passage.
(D) CORRECT. This choice reflects the summary above: why COX-2 inhibitors were developed and the result of the drugs' introduction into the marketplace.
(E) This is incorrect because the passage never mentions a drug class of “COX-1 inhibitors.” COX-1 is introduced as an enzyme; it is not a class of drug.

The "True/False" technique is useful for EXCEPT questions. Four of the answer choices will contain information found in the passage; these will be labeled True. One answer choice will contain information not found in the passage; it will be labeled False.
(A) True. Paragraph 2 states “prostaglandins were first discovered in the 1930s."
(B) True. Paragraph 2 states prostaglandins are "generated by most mammalian tissues.”
(C) True. Paragraph 1 states that prostaglandins are "responsible for producing the sensation of pain in the human body, among other functions.”
(D) CORRECT: False. The author never claims that prostaglandins cause side effects. According to paragraph 4, the COX inhibitor drugs, not prostaglandins, caused side effects that went undetected during clinical trials.
(E) True. Paragraph 2 states that “aspirin alleviates pain by inhibiting... COX; this inhibition prevents the production of prostaglandins" and goes on to list the three forms of the enzyme, COX-1, COX-2, and COX-3.

The word "suggests" in the question indicates that this is an inference question. The correct answer, therefore, will not be directly stated in the passage, but it will be based only on information found within the passage, with no outside speculation or assumptions necessary.

(A) Paragraph 2 states that COX-1 enzymes stimulate production of prostaglandins that "protect the stomach from irritating gastric acids.” As stated in paragraph 3, however, COX-2 inhibitors were designed to affect only COX-2; the specific impetus was not to interrupt the beneficial effects of COX-1.

(B) The author never describes the side effects caused by COX-2 and furthermore he states in paragraph 3 that the COX-2 drugs were designed “in order to eliminate the side effects of aspirin and related drugs.” Paragraph 2 states that Naproxen is one of those related drug.

(C) CORRECT: Paragraph 3 states that the drug class known as COX-2 inhibitors was introduced by “several pharmaceutical companies in the 1990s." Paragraph 1 states “their mechanisms of action having been discovered only in 1971." This suggests that approximately 20 years passed between the initial discovery and the introduction of COX-2 inhibitors.

(D) This choice is incorrect as it describes COX-2 enzymes, not COX-2 inhibitors; in addition, the information is directly stated in the passage rather than suggested. Paragraph 2 states that COX-2 appears to stimulate production of prostaglandins that "induce inflammation in injured tissues.”

(E) This choice is incorrect as it describes prostaglandins, not the drug class COX-2 inhibitors. Paragraph 2 states that prostaglandins are "generated by most mammalian tissues in response to external stimuli" and "prostaglandins act on the cells that produce them."

If prostaglandins are a response to external stimuli, or stimuli outside of the body, then that external stimuli must be closely linked to at least one of the major functions of prostaglandin.
(A) Stomach ulcers are produced or aggravated by aspirin and similar drugs, not prostaglandins (and, in fact, these drugs inhibit prostaglandins).
(B) It is mentioned in the passage that “prostaglandins act on the cells that produce them,” but the author does not draw a connection between where prostaglandins act and what (i.e. external stimuli) generates their production.
(C) Paragraph 2 states that aspirin, not prostaglandin, prevents cyclooxygenase from functioning.
(D) Paragraph 2 states that most mammalian hormones "are synthesized in one tissue but act on a distant one" and contrasts prostaglandins, which "act on the cells that produce them" or on other nearby cells. This difference is based upon where the hormones act, not on what the hormones are responding to (whether external stimuli or something else).
(E) CORRECT: Paragraph 1 states that prostaglandins are "responsible for producing the sensation of pain in the human body, among other functions.” In the second paragraph the author mentions that aspirin alleviates pain by preventing the production of prostaglandins. To bridge the two assertions, the author provides evidence that prostaglandins are indeed responsible for the sensation of pain, an external stimuli.