GMAT exam

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.

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Answer: A

A . greater than 1
B . greater than or equal to 1
C . not equal to -1
D . less than or equal to 1
E . less than 1

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Answer: B

Under United States law, a distinctive package design can be legally protected against copying. Lorex shampoo, a leading brand, is packaged in a triangular-shaped bottle with a gold label. A major pharmacy chain has introduced a similar, less expensive shampoo in similarly shaped bottles with plain black-and-white labels carrying the chain’s name. Though the triangular shape is distinctive, the manufacturer of Lorex has not legally challenged its use for the chain’s shampoo.

Which of the following, if true, provides the strongest reason for the manufacturer of Lorex not to challenge the chain’s use of the triangular package design?
A . The manufacturer of Lorex depends for sales on the willingness of the chain to stock Lorex and other of the manufacturer’s products.
B . The black-and-white labeling of the chain’s shampoo indicates to the consumer that irrelevant expense has been spared in order to bring the product to the consumer at lower cost.
C . The cost of manufacturing the chain’s shampoo is substantially lower than the cost of manufacturing Lorex.
D . Lawsuits brought for the purpose of protecting distinctive package designs are generally successful.
E . The manufacturer of Lorex also manufactures other shampoos, and those shampoos are not sold in triangular-shaped bottles.

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Answer: E

Manufacturers and retailers tend to look askance at gray markets, where products are sold at cut-rate prices outside their authorized distribution channels. Manufacturers fear that gray markets will undercut margins and tarnish brand names. Retailers fear that they will siphon away customers and erode prices.

A new study indicates, however, that gray marketing actually benefits manufacturers and retailers in markets that meet two criteria: first, sharp differences exist in consumers’ price sensitivity; second, large numbers of consumers are price-insensitive. In such markets, the low prices of the gray market will attract the most price-sensitive customers. The authorized channels will then compete only for the remaining customers―those who are insensitive to price but sensitive to service.

When that happens, the structure of competition and the economics of the market shift. The authorized retailers, freed from having to cater to the bargain hunters, can raise their prices and focus on service. If the concentration of price-insensitive shoppers is high enough, the resulting increase in prices will more than offset the loss of sales to the bargain hunters. The margins and profits of the authorized retailers will increase, and manufacturers will, as a result, be able to boost their wholesale prices.

Which of the following, if true, would most undermine the reasoning offered for the claim that gray markets can in certain conditions lead to increased profits among authorized retailers?
A . More consumers have become price-sensitive over the last ten years and this trend will continue for the foreseeable future.
B . Gray markets typically remain strong even in markets where authorized retailers have introduced service enhancements.
C . Price wars among authorized retailers, triggered by the appearance of gray markets when few, if any, consumers are price-insensitive, lead to a cycle of increasing price reductions that severely narrow profit margins.
D . Authorized retailers who are competing for the business of price-insensitive consumers often become involved in a cycle of expensive service enhancements that significantly narrow profit margins.
E . Manufacturers who fear that gray marketing will tarnish their brand names sometimes subsidize advertising for authorized retailers, thereby narrowing the manufacturers’ profit margins.

View Answer

Answer: D

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 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 first two sentences of the second paragraph serve primarily to
A . provide an example of a species that relies on the help of another species in defending itself against a particular predator
B . provide a point of reference against which the author’s description of a related phenomenon can be compared
C . introduce a phenomenon that casts doubt on experimental results described later in the passage
D . introduce the phenomenon that the experiment described later in the passage is designed to explain
E . offer a conventional but probably inaccurate view of how many plants defend themselves from predators

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Answer: D

The decision as to when to bring charges for a criminal offense is the prerogative of the prosecutor, not the prospective defendant. This prerogative should not be put to unfair advantage. Sometimes decades elapse before charges are brought. Though this may be appropriate when striking new evidence implicates someone, bringing charges after many years simply because evidence favoring the prospective defendant has become inaccessible would be grossly unjust.

Which of the following most accurately states the passage’s main point?
A . There should be safeguards to prevent criminal prosecutors from taking unfair advantage of the prerogative to decide when charges will be brought against a prospective defendant.
B . Criminal prosecutors have an advantage over prospective defendants in that prosecutors get to decide when, if at all, charges will be brought.
C . Criminal prosecutors should not take unfair advantage of their prerogative to decide when criminal charges will be brought against a prospective defendant.
D . In some cases, it is unfair for a prosecutor, many years after an alleged offense has
occurred, to bring charges against a prospective defendant for committing that offense.
E . To bring charges against a prospective defendant after a delay of many years would be
unjust.

View Answer

Answer: D

When new regulations were imposed on businesses selling in the same markets as Acme Inc. and the demographics began to change unfavorably for its main product: there was very little that it could have done different in the short term.
A . product; there was very little that it could have done different in the short term
B . product, there was very little they could have done different in the short term
C . product, so there was very little could be done differently by the firm in the short term
D . product, there was very little possible in the short term for them to do differently
E . product, there was very little that the firm could have done differently in the short term

View Answer

Answer: E

Manufacturers and retailers tend to look askance at gray markets, where products are sold at cut-rate prices outside their authorized distribution channels. Manufacturers fear that gray markets will undercut margins and tarnish brand names. Retailers fear that they will siphon away customers and erode prices.

A new study indicates, however, that gray marketing actually benefits manufacturers and retailers in markets that meet two criteria: first, sharp differences exist in consumers’ price sensitivity; second, large numbers of consumers are price-insensitive. In such markets, the low prices of the gray market will attract the most price-sensitive customers. The authonzed channels will then compete only for the remaining customers―those who are insensitive to price but sensitive to service.

When that happens, the structure of competition and the economics of the market shift. The authorized retailers, freed from having to cater to the bargain hunters, can raise their prices and focus on service. If the concentration of price-insensitive shoppers is high enough, the resulting increase in prices will more than offset the loss of sales to the bargain hunters. The margins and profits of the authorized retailers will increase, and manufacturers will, as a result, be able to boost their wholesale prices.

The primary purpose of the passage is to
A . explain how, in certain types of markets, gray marketing can improve margins and profits for manufacturers and authorized retailers
B . identify the effects, both beneficial and detrimental, that gray markets have on manufacturers and authorized retailers
C . outline a course of action that manufacturers and authorized retailers can take to gain benefits from gray marketing
D . present the results of a study that indicates that under most conditions gray markets are beneficial to manufacturers and authorized retailers
E . provide arguments for and against the view that gray markets are beneficial to manufacturers and authorized retailers

View Answer

Answer: A

Members of many primate species approach an opponent shortly after conflict and initiate behaviors such as embracing, grooming, or huddling―a phenomenon researchers call postconflict reconciliation. Existing research, however, suffers from several shortcomings.

The variability between groups of the same species is rarely addressed; the majority of studies investigate only a small fraction of the pairings that exist in a given group; and almost all reports are restricted to animals in captivity.

In an attempt to address some of these shortcomings, Sommer et al. recentfy conducted a study of postconflict reconciliation in wild Hanuman langurs, a species of colobine monkey. They observed rates of postconflict reconciliation much lower than would be expected based on previous research, and found that over 80 percent of all pairings exhibited no postconflict affinity whatsoever. The rarity of friendly postconflict reunion in wild langurs draws attention to the possibility that conflicts are modulated through avoidance. The option of temporarily avoiding contact with opponents is not easily available to captive primates, and certainly not to the extent present in the wild. Still, studies of postconflict behavior of primates in captivity remain valuable: above all, they demonstrate the flexibility of nonhuman primates in various environments. It is likely, however, that the reported frequency of reconciliation among primates is artificially inflated by the conditions of captivity.

According to the passage, the majority of the pairings observed in Sommer’s study exhibited postconflict affinity under what conditions?
A . Only when one member of the pair was markedly stronger than the other
B . Only during certain times of the year, such as mating season
C . More often in the form of huddling than in the form of grooming
D . More often while held in captivity than when interacting in the wild
E . At no time whatsoever

View Answer

Answer: D

In the figure above, circular regions and represent sets of integers and every integer greater than 2 is in Mor A, or in both. Is the integer 11 in the shaded region?

(1) Mrepresents the set of integers greater than 2 that are not prime.

(2) Mrepresents the set of odd integers greater than 2.
A . Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B . Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C . BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D . EACH statement ALONE is sufficient.
E . Statements (1) and (2) TOGETHER are NOT sufficient.

View Answer

Answer: C