GMAT Verbal : Analyzing Argumentative Claims, Bias, and Support in Natural Science Passages

Study concepts, example questions & explanations for GMAT Verbal

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Example Questions

Example Question #2 : Understanding Style, Argument, And Organization In Natural Science Passages

Adapted from “Humming-Birds: As Illustrating the Luxuriance of Tropical Nature” in Tropical Nature, and Other Essays by Alfred Russel Wallace (1878)

The food of hummingbirds has been a matter of much controversy. All the early writers down to Buffon believed that they lived solely on the nectar of flowers, but since that time, every close observer of their habits maintains that they feed largely, and in some cases wholly, on insects. Azara observed them on the La Plata in winter taking insects out of the webs of spiders at a time and place where there were no flowers. Bullock, in Mexico, declares that he saw them catch small butterflies, and that he found many kinds of insects in their stomachs. Waterton made a similar statement. Hundreds and perhaps thousands of specimens have since been dissected by collecting naturalists, and in almost every instance their stomachs have been found full of insects, sometimes, but not generally, mixed with a proportion of honey. Many of them in fact may be seen catching gnats and other small insects just like fly-catchers, sitting on a dead twig over water, darting off for a time in the air, and then returning to the twig. Others come out just at dusk, and remain on the wing, now stationary, now darting about with the greatest rapidity, imitating in a limited space the evolutions of the goatsuckers, and evidently for the same end and purpose. Mr. Gosse also remarks, ” All the hummingbirds have more or less the habit, when in flight, of pausing in the air and throwing the body and tail into rapid and odd contortions. This is most observable in the Polytmus, from the effect that such motions have on the long feathers of the tail. That the object of these quick turns is the capture of insects, I am sure, having watched one thus engaged pretty close to me.”

What evidence does Mr. Gosse have to support the claim that hummingbirds eat insects?

Possible Answers:

He surmised that they must eat insects because he has never seen one eating flower nectar.

He observed one flailing around in the air and concluded that it was eating insects.

He examined the contents of a hummingbird’s stomach and found many insects in it.

A hummingbird got into his collection of live insects, and soon after, all of his insects were missing.

He read in a reputable scientific journal that they eat insects.

Correct answer:

He observed one flailing around in the air and concluded that it was eating insects.

Explanation:

To answer this question, we have to consider the quotation attributed to Mr. Gosse found at the end of the passage:

“Mr. Gosse also remarks, ‘All the hummingbirds have more or less the habit, when in flight, of pausing in the air and throwing the body and tail into rapid and odd contortions. This is most observable in the Polytmus, from the effect that such motions have on the long feathers of the tail. That the object of these quick turns is the capture of insects, I am sure, having watched one thus engaged pretty close to me.’”

He doesn’t mention anything about having a collection of live insects, getting his information from a scientific journal, or dissecting a hummingbird’s stomach, so we can ignore those answer choices. He actively observes a hummingbird and surmises that they eat insects because of that, so the correct answer is “He observed one flailing around in the air and concluded that it was eating insects.”

Example Question #1 : Authorial Purpose In Natural Science Passages

Adapted from “Birds in Retreat” in “Animal Defences—Active Defence” in Volume Four of The Natural History of Animals: The Animal Life of the World in Its Various Aspects and Relations by James Richard Ainsworth Davis (1903)

Among the large running birds are forms, like the African ostrich, in which the absence of powers of flight is largely compensated by the specialization of the legs for the purpose of rapid movement on the ground. For straightforward retreat in open country nothing could be more effective; but another kind of adaptation is required in birds like rails, which are deficient in powers of flight, and yet are able to run through thickly-growing vegetation with such rapidity as to commonly elude their enemies. This is rendered possible by the shape of their bodies, which are relatively narrow and flattened from side to side, so as to easily slip between the stems of grasses, rushes, and similar plants. Anyone who has pursued our native land-rail or corn-crake with intent to capture will have noted how extremely difficult it is even to get within sight of a bird of this sort. 

Certain birds, unfortunately for themselves, have lost the power of flight without correspondingly increased powers of running, and have paid the penalty of extinction. Such an arrangement, as might be anticipated, was the result of evolution in islands devoid of any predatory ground-animals, and a classic example of it is afforded by the dodo and its allies, birds related to the pigeons. The dodo itself was a large and clumsy-looking species that at one time abounded in the island of Mauritius, which, like oceanic islands generally, possessed no native mammals, while its indigenous reptiles were only represented by lizards. The ubiquitous sailor, however, and the animals (especially swine) which he introduced, brought about the extinction of this helpless bird in less than a century after its first discovery in 1598. Its memory is now only kept green by a few contemporary drawings and descriptions, certain museum remains, and the proverb "as extinct as a dodo.” A similar fate must overtake any organism suddenly exposed to new and unfavorable conditions, if devoid of sufficient plasticity to rapidly accommodate itself to the altered environment.

The narrator mentions the proverb “as extinct as a dodo” in order to __________.

Possible Answers:

lament that the dodo was not eliminated sooner

encourage his readers to use more figurative language

transition to a discussion of the ways in which common sayings reference birds

provide an example of what little is left of the dodo in his era

support the idea that the dodo went extinct because of human influence

Correct answer:

provide an example of what little is left of the dodo in his era

Explanation:

The author mentions the proverb “as extinct as a dodo” in the second paragraph, when he states, “[The dodo’s] memory is now only kept green by a few contemporary drawings and descriptions, certain museum remains, and the proverb ‘as extinct as a dodo.’” The author is clearly not mentioning the proverb in order to “lament that the dodo was not eliminated sooner”; we can tell this from the rest of the paragraph as well, in that he is saddened that it went extinct at all. The author isn’t urging his readers to do anything, so he can’t be using the proverb to “encourage his readers to use more figurative language.” He doesn’t begin to discuss the ways in which common sayings reference birds after this point, so it doesn’t make any sense to say that he uses the proverb as a transition to such a discussion. This leaves us with two answer choices: that he mentions the proverb to “support the idea that the dodo went extinct because of human influence” and that he does so to “provide an example of what little is left of the dodo in his era.” While this may seem like a somewhat tricky choice, it is important to realize that at this point, the author has made the point that the dodo went extinct due to human influence in an earlier sentence, and this sentence doesn’t mention the reasons why the dodo went extinct at all—it’s talking about what is left over now that the dodo is extinct. This means that the correct answer is that the author mentions this proverb in order to “provide an example of what little is left of the dodo in his era.”

Example Question #1 : Analyzing Argumentative Claims, Bias, And Support In Natural Science Passages

Passage adapted from Animal Sanctuaries in Labrador (1911) by W. Wood

A sanctuary may be defined as a place where Man is passive and the rest of Nature active. Till quite recently Nature had her own sanctuaries, where man either did not go at all or only as a tool-using animal in comparatively small numbers. But now, in this machinery age, there is no place left where man cannot go with overwhelming forces at his command. He can strangle to death all the nobler wild life in the world to-day. To-morrow he certainly will have done so, unless he exercises due foresight and self-control in the mean time.

There is not the slightest doubt that birds and mammals are now being killed off much faster than they can breed. And it is always the largest and noblest forms of life that suffer most. The whales and elephants, lions and eagles, go. The rats and flies, and all mean parasites, remain. This is inevitable in certain cases. But it is wanton killing off that I am speaking of to-night. Civilized man begins by destroying the very forms of wild life he learns to appreciate most when he becomes still more civilized. The obvious remedy is to begin conservation at an earlier stage, when it is easier and better in every way, by enforcing laws for close seasons, game preserves, the selective protection of certain species, and sanctuaries.

I have just defined a sanctuary as a place where man is passive and the rest of Nature active. But this general definition is too absolute for any special case. The mere fact that man has to protect a sanctuary does away with his purely passive attitude. Then, he can be beneficially active by destroying pests and parasites, like bot-flies or mosquitoes, and by finding antidotes for diseases like the epidemic which periodically kills off the rabbits and thus starves many of the carnivora to death. But, except in cases where experiment has proved his intervention to be beneficial, the less he upsets the balance of Nature the better, even when he tries to be an earthly Providence.

The author implies that his first definition of a sanctuary is ___________.

Possible Answers:

indefensible

irrelevant

too romantic

somewhat misguided

indisputable 

Correct answer:

too romantic

Explanation:

In the second sentence, the author states that his previous definition was “too absolute”. He also offers that the less man “upsets the balance of Nature” the better. So he admits his definition is not entirely right because it is too idealistic, but it is not entirely wrong either. It is now easy to eliminate answers the other strongly negative answers.

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