PSAT Critical Reading : Natural Science Passages

Study concepts, example questions & explanations for PSAT Critical Reading

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Example Questions

Example Question #12 : Making Inferences And Predictions In Science Passages

Adapted from “Feathers of Sea Birds and Wild Fowl for Bedding” from The Utility of Birds by Edward Forbush (ed. 1922)

In the colder countries of the world, the feathers and down of waterfowl have been in great demand for centuries as filling for beds and pillows. Such feathers are perfect non-conductors of heat, and beds, pillows, or coverlets filled with them represent the acme of comfort and durability. The early settlers of New England saved for such purposes the feathers and down from the thousands of wild-fowl which they killed, but as the population increased in numbers, the quantity thus furnished was insufficient, and the people sought a larger supply in the vast colonies of ducks and geese along the Labrador coast. 

The manner in which the feathers and down were obtained, unlike the method practiced in Iceland, did not tend to conserve and protect the source of supply. In Iceland, the people have continued to receive for many years a considerable income by collecting eider down, but there they do not “kill the goose that lays the golden eggs.” Ducks line their nests with down plucked from their own breasts and that of the eider is particularly valuable for bedding. In Iceland, these birds are so carefully protected that they have become as tame and unsuspicious as domestic fowls In North America. Where they are constantly hunted they often conceal their nests in the midst of weeds or bushes, but in Iceland, they make their nests and deposit their eggs in holes dug for them in the sod. A supply of the ducks is maintained so that the people derive from them an annual income.

In North America, quite a different policy was pursued. The demand for feathers became so great in the New England colonies about the middle of the eighteenth century that vessels were fitted out there for the coast of Labrador for the express purpose of securing the feathers and down of wild fowl. Eider down having become valuable and these ducks being in the habit of congregating by thousands on barren islands of the Labrador coast, the birds became the victims of the ships’ crews. As the ducks molt all their primary feathers at once in July or August and are then quite incapable of flight and the young birds are unable to fly until well grown, the hunters were able to surround the helpless birds, drive them together, and kill them with clubs. Otis says that millions of wildfowl were thus destroyed and that in a few years their haunts were so broken up by this wholesale slaughter and their numbers were so diminished that feather voyages became unprofitable and were given up. 

This practice, followed by the almost continual egging, clubbing, shooting, etc. by Labrador fishermen, may have been a chief factor in the extinction of the Labrador duck, that species of supposed restricted breeding range. No doubt had the eider duck been restricted in its breeding range to the islands of Labrador, it also would have been exterminated long ago.

Which of the following most likely happened after the Labrador feather voyages were no longer organized?

Possible Answers:

The price of eider down in North America plummeted.

A population of the Labrador duck was reestablished.

North Americans imported eider down from Iceland.

The quality of bedding in North America became preferable to that found in Iceland.

Eider down began to be used for other purposes in North America.

Correct answer:

North Americans imported eider down from Iceland.

Explanation:

The first paragraph tells us that the Labrador feather voyages were organized to keep up with an increased demand for eider down caused by an increased North American population. The passage doesn’t mention any alternative sources of eider down being used after the Labrador feather voyages were no longer organized. Therefore, we can eliminate the answer choice “The price of eider down in North America plummeted” since if eider down became more rare, its price would likely have gone up, not down. We can also eliminate the answer choice “Eider down began to be used for other purposes in North America” as this is not suggested in the passage at all and would require more information to be supported. “The quality of bedding in North America became preferable to that found in Iceland” cannot be correct either, as in the first paragraph, the author claims that eider down makes the best bedding, and if eider down becomes rare in North America, it’s not likely that the quality of North American bedding will exceed that of bedding made in Iceland, where eider down is assumed to be more available. “A population of the Labrador duck was reestablished.” cannot be the correct answer because the passage tells us that the Labrador duck went extinct, and if a species is extinct, there are no living members left from which populations of it could be reestablished. This leaves us with one answer, the correct one: “North American populations had to import eider down from Iceland.” This makes sense, as if less eider down were available in North America but there was still a desire for it, it would be likely to be imported from elsewhere in the world.

Example Question #2 : Science

Adapted from "Recent Views as to Direct Action of Light on the Colors of Flowers and Fruits" in Tropical Nature, and Other Essays by Alfred Russel Wallace (1878)

The theory that the brilliant colors of flowers and fruits is due to the direct action of light has been supported by a recent writer by examples taken from the arctic instead of from the tropical flora. In the arctic regions, vegetation is excessively rapid during the short summer, and this is held to be due to the continuous action of light throughout the long summer days. “The further we advance towards the north, the more the leaves of plants increase in size as if to absorb a greater proportion of the solar rays. M. Grisebach says that during a journey in Norway he observed that the majority of deciduous trees had already, at the 60th degree of latitude, larger leaves than in Germany, while M. Ch. Martins has made a similar observation as regards the leguminous plants cultivated in Lapland.” The same writer goes on to say that all the seeds of cultivated plants acquire a deeper color the further north they are grown, white haricots becoming brown or black, and white wheat becoming brown, while the green color of all vegetation becomes more intense. The flowers also are similarly changed: those which are white or yellow in central Europe becoming red or orange in Norway. This is what occurs in the Alpine flora, and the cause is said to be the same in both—the greater intensity of the sunlight. In the one the light is more persistent, in the other more intense because it traverses a less thickness of atmosphere.

Admitting the facts as above stated to be in themselves correct, they do not by any means establish the theory founded on them; and it is curious that Grisebach, who has been quoted by this writer for the fact of the increased size of the foliage, gives a totally different explanation of the more vivid colors of Arctic flowers. He says, “We see flowers become larger and more richly colored in proportion as, by the increasing length of winter, insects become rarer, and their cooperation in the act of fecundation is exposed to more uncertain chances.” (Vegetation du Globe, col. i. p. 61—French translation.) This is the theory here adopted to explain the colors of Alpine plants, and we believe there are many facts that will show it to be the preferable one. The statement that the white and yellow flowers of temperate Europe become red or golden in the Arctic regions must we think be incorrect. By roughly tabulating the colors of the plants given by Sir Joseph Hooker as permanently Arctic, we find among fifty species with more or less conspicuous flowers, twenty-five white, twelve yellow, eight purple or blue, three lilac, and two red or pink; showing a very similar proportion of white and yellow flowers to what obtains further south.

The author of the passage is most likely __________.

Possible Answers:

a botanist

a geographer

a meteorologist

a chemist

an archeologist

Correct answer:

a botanist

Explanation:

As the title of the passage is "Recent Views as to Direct Action of Light on the Colors of Flowers and Fruits" and its subject is flower color, leaf size, and other scientific phenomena that have to do with plants, trees, and especially flowers, we can safely infer that of the given answer choices, the author is most likely a botanist. While the author does discuss flowers at different latitudes, which may suggest "geographer," and different atmospheric conditions, which may suggest "meteorologist," he only broaches these topics because of how they intersect with his primary topic of flowers and plants.

Example Question #1 : Drawing Generalizations About Natural Science Passages

Adapted from "Recent Views as to Direct Action of Light on the Colors of Flowers and Fruits" in Tropical Nature, and Other Essays by Alfred Russel Wallace (1878)

The theory that the brilliant colors of flowers and fruits is due to the direct action of light has been supported by a recent writer by examples taken from the arctic instead of from the tropical flora. In the arctic regions, vegetation is excessively rapid during the short summer, and this is held to be due to the continuous action of light throughout the long summer days. "The further we advance towards the north, the more the leaves of plants increase in size as if to absorb a greater proportion of the solar rays. M. Grisebach says that during a journey in Norway he observed that the majority of deciduous trees had already, at the 60th degree of latitude, larger leaves than in Germany, while M. Ch. Martins has made a similar observation as regards the leguminous plants cultivated in Lapland.” The same writer goes on to say that all the seeds of cultivated plants acquire a deeper color the further north they are grown, white haricots becoming brown or black, and white wheat becoming brown, while the green color of all vegetation becomes more intense. The flowers also are similarly changed: those which are white or yellow in central Europe becoming red or orange in Norway. This is what occurs in the Alpine flora, and the cause is said to be the same in both—the greater intensity of the sunlight. In the one the light is more persistent, in the other more intense because it traverses a less thickness of atmosphere.

Admitting the facts as above stated to be in themselves correct, they do not by any means establish the theory founded on them; and it is curious that Grisebach, who has been quoted by this writer for the fact of the increased size of the foliage, gives a totally different explanation of the more vivid colors of Arctic flowers. He says, “We see flowers become larger and more richly colored in proportion as, by the increasing length of winter, insects become rarer, and their cooperation in the act of fecundation is exposed to more uncertain chances.” (Vegetation du Globe, col. i. p. 61—French translation.) This is the theory here adopted to explain the colors of Alpine plants, and we believe there are many facts that will show it to be the preferable one. The statement that the white and yellow flowers of temperate Europe become red or golden in the Arctic regions must we think be incorrect. By roughly tabulating the colors of the plants given by Sir Joseph Hooker as permanently Arctic, we find among fifty species with more or less conspicuous flowers, twenty-five white, twelve yellow, eight purple or blue, three lilac, and two red or pink; showing a very similar proportion of white and yellow flowers to what obtains further south.

This passage is taken from a longer work. Based on what you have read, which of the following would you most expect to find in the paragraphs immediately following those in the passage?

Possible Answers:

A summary of a paper the author wishes to publish on the topic being discussed

A discussion of the historical uses of alpine plants

Praise of the useful nature of Hooker’s research

More evidence as to why Grisebach’s theory is the correct one

Further consideration of the theory of the writer quoted in the first paragraph

Correct answer:

More evidence as to why Grisebach’s theory is the correct one

Explanation:

In the concluding sentences of the passage, the author is asserting that Grisebach's interpretation is the correct one, not that of the "recent writer" quoted in the first paragraph. The author is also bringing up evidence (Joseph Hooker's enumerated observations) to prove his point. One could thus reasonably expect to encounter "more evidence as to why Grisebach’s theory is the correct one" if one read on further in the larger text of which this passage is a small part.

Example Question #22 : Inferences And Predictions In Narrative Science Passages

Adapted from "Taking a Second Look: An Analysis of Genetic Markers in Species Relatedness" by Joseph Ritchie (2014)

Phylogenetics is the study of genetic composition in various species and is used by evolutionary biologists to investigate similarities in the molecular sequences of proteins in varying organisms. The amino acid sequences that build proteins are used to construct mathematical matrices that aid in determining evolutionary ties through the investigation of percentage similarities. The study of these matrices helps to expose evolutionary relationships between species that may not have the same overt characteristics.

Species adapt and evolve based on the pressures that exist in their environment. Climate, food source, and habitat availability are only a few factors that act on species adaptation. These stressors can alter the physical characteristics of organisms. This divergence in evolution has made it difficult to determine the interrelatedness of organisms by analyzing their physical characteristics alone.

For instance, looking only at physical characteristics, the ghost bat resembles a pigeon more than a spider monkey; however, phylogenetics has found that the amino acid sequences that construct the beta hemoglobin molecules of bats are twenty percent more similar to those of mammalian primates than those of birds. This helps reject the assumption that common physical characteristics between species are all that is needed to determine relatedness. 

The differences produced by divergent evolution observed in the forest-dwelling, arboreal spider monkey and the nocturnal, airborne ghost bat can be reconciled through homology. Homologous characteristics are anatomical traits that are similar in two or more different species. For instance, the bone structure of a spider monkey’s wrist and fingers greatly resembles that of a bat’s wing or even a whale’s fin. These similarities are reinforced by phylogenetic evidence that supports the idea that physically dissimilar species can be evolutionarily related through anatomical and genetic similarities.

A scientist studied the relatedness of several reptilian species solely by investigating fossil evidence and has concluded that physical characteristics alone are enough to determine species relatedness. Would this scientist agree with the claims made by phylogenetic research?

Possible Answers:

No, because phylogenetics is an unreliable and new technique that has yet to prove itself in major scientific arenas.

Yes, because phylogenetics is second to physical comparisons and thus supports the archaeologist's position.

None of the other choices are correct.

No, because phylogenetics assumes that physical traits and characteristics are not the only objective and reliable markers in the study of species relatedness.

Correct answer:

No, because phylogenetics assumes that physical traits and characteristics are not the only objective and reliable markers in the study of species relatedness.

Explanation:

The scientist studied relatedness based on the fossil record of physical traits. Having studied this, he would not agree with the notion that phylogenetics may better explain relatedness via genetic factors. The rest of the choices are incorrect because they are not supported by the passage.

Example Question #1 : Considering Analogous Concepts In Natural Science Passages

Adapted from "Taking a Second Look: An Analysis of Genetic Markers in Species Relatedness" by Joseph Ritchie (2014)

Phylogenetics is the study of genetic composition in various species and is used by evolutionary biologists to investigate similarities in the molecular sequences of proteins in varying organisms. The amino acid sequences that build proteins are used to construct mathematical matrices that aid in determining evolutionary ties through the investigation of percentage similarities. The study of these matrices helps to expose evolutionary relationships between species that may not have the same overt characteristics.

Species adapt and evolve based on the pressures that exist in their environment. Climate, food source, and habitat availability are only a few factors that act on species adaptation. These stressors can alter the physical characteristics of organisms. This divergence in evolution has made it difficult to determine the interrelatedness of organisms by analyzing their physical characteristics alone.

For instance, looking only at physical characteristics, the ghost bat resembles a pigeon more than a spider monkey; however, phylogenetics has found that the amino acid sequences that construct the beta hemoglobin molecules of bats are twenty percent more similar to those of mammalian primates than those of birds. This helps reject the assumption that common physical characteristics between species are all that is needed to determine relatedness. 

The differences produced by divergent evolution observed in the forest-dwelling, arboreal spider monkey and the nocturnal, airborne ghost bat can be reconciled through homology. Homologous characteristics are anatomical traits that are similar in two or more different species. For instance, the bone structure of a spider monkey’s wrist and fingers greatly resembles that of a bat’s wing or even a whale’s fin. These similarities are reinforced by phylogenetic evidence that supports the idea that physically dissimilar species can be evolutionarily related through anatomical and genetic similarities.

According to the passage, the hemoglobin structure of a bat is most similar to which of the following animals?

Possible Answers:

Hummingbird

Spider monkey

Eagle

Pigeon

Correct answer:

Spider monkey

Explanation:

The spider monkey is the only mammalian species listed in the choices. The other choices are birds, which the passage states are less similar to bats than mammals. Therefore, also being a mammalian species, spider monkey is the correct answer. 

Example Question #4 : Understanding The Content Of Natural Science Passages

"Darwinism's Effect on Science" by Matthew Minerd (2014)

For much of the history of human thought, the sciences have studied subjects that seemed to be eternal and unchanging. Even the basic laws of the Nile’s flooding were investigated in the hopes of finding never-altering laws. Similarly, the scientific investigations of the ancient Near East and Greece into the regular laws of the stars ultimately looked for constant patterns. This overall pattern of scientific reasoning has left deep marks on the minds of almost all thinkers and found its apotheosis in modern physics. From the time of the early renaissance to the nineteenth century, physics represented the ultimate expression of scientific investigation for almost all thinkers. Its static laws appeared to be the unchanging principles of all motion and life on earth. By the nineteenth century, it had appeared that only a few details had to be “cleared up” before all science was basically known.

In many ways, this situation changed dramatically with the arrival of Darwinism. It would change even more dramatically in early twentieth-century physics as well. Darwin’s theories of evolution challenged many aspects of the “static” worldview. Even those who did not believe that a divine being created an unchanging world were shaken by the new vistas opened up to science by his studies. It had been a long-accepted inheritance of Western culture to believe that the species of living organisms were unchanging in nature. Though there might be many different kinds of creatures, the kinds themselves were not believed to change. The thesis of a universal morphing of types shattered this cosmology, replacing the old world-view with a totally new one. Among the things that had to change in light of Darwin’s work was the very view of science held by most people.

Which of the following provides an example of the main idea asserted in the first paragraph?

Possible Answers:

The Pythagorean theorem is based upon the constant relationship of the sides of a right triangle to its hypotenuse.

The fluctuation of coloration within a species is rather minimal.

The interest in science only arises once agriculture reaches a certain point of fixity.

Religion constantly wanes with the rise of science.

None of the other answers

Correct answer:

The Pythagorean theorem is based upon the constant relationship of the sides of a right triangle to its hypotenuse.

Explanation:

The first paragraph discusses the role of necessary connections and unvarying rules in scientific thinking, particularly the type of thinking that has played a prominent role in Western thought for many centuries. The example of the Pythagorean theorem is a good example of this.  Even if you do not know this mathematical equation, you can tell that this is the correct answer by the words "constant relationship."

Example Question #1 : Locating Details In Narrative 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.”

How does the quotation from Mr. Gosse relate to the evidence provided by other scientists earlier in the passage?

Possible Answers:

It supports the same conclusions that the previous evidence supports.

It suggests that the earlier evidence applies not only to hummingbirds but to another type of bird as well.

It suggests that some of the previous evidence may be true, but some may be false.

It contradicts the previous evidence and supports a different hypothesis.

It has nothing to do with the previous evidence.

Correct answer:

It supports the same conclusions that the previous evidence supports.

Explanation:

Let’s consider what Mr. Gosse is saying. The passage says, “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.’”  Paraphrasing that, Mr. Gosse is saying that he has seen hummingbirds contort themselves in the air and he’s pretty sure they’re doing this in order to catch insects. The evidence provided by scientists earlier in the passage supports the idea that hummingbirds eat insects, just like Mr. Gosse’s does. We can’t say that Gosse’s evidence contradicts the earlier evidence, suggests that some of it may be false, or has nothing to do with the previous evidence. It also doesn’t suggest that the previous evidence can be applied to birds other than hummingbirds, because Mr. Gosse says that he is only discussing hummingbirds and we are to infer that the Polytmus is a hummingbird. So, the correct answer is that “it supports the same conclusions that the previous evidence supports.”

Example Question #3 : Comparing And Contrasting 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.”

Which of the following does the author contrast in this passage?

Possible Answers:

The results of feeding a hummingbird insects and the results of feeding a hummingbird flower nectar

The author’s opinion about what hummingbirds eat and Mr. Gosse’s opinion about what hummingbirds eat

Hummingbirds with long tails and hummingbirds with short tails

Hummingbirds that eat flower nectar and hummingbirds that eat insects

The beliefs of historical scientists and the beliefs of scientists of the author’s time

Correct answer:

The beliefs of historical scientists and the beliefs of scientists of the author’s time

Explanation:

Nowhere in the passage is the feeding of hummingbirds by humans mentioned, so “The results of feeding a hummingbird insects and the results of feeding a hummingbird flower nectar” cannot be correct. While a hummingbird with a long tail, the Polytmus, is mentioned, it is not contrasted with any short-tailed hummingbirds. The author appears to agree with Mr. Gosse’s opinion about what hummingbirds eat, so “The author’s opinion about what hummingbirds eat and Mr. Gosse’s opinion about what hummingbirds eat” cannot be correct either. This leaves us with “Hummingbirds that eat flower nectar and hummingbirds that eat insects” and “the beliefs of historical scientists and the beliefs of scientists of the author’s time.” While the passage is concerned with what hummingbirds eat, it doesn’t suggest that some types of hummingbirds eat only nectar and others eat only insects. Hummingbirds are considered as an entire group; they’re never divided into “hummingbirds that eat insects” and “hummingbirds that eat flower nectar.” This leaves us with one answer choice, the correct one: “The beliefs of historical scientists and the beliefs of scientists of the author’s time.” These beliefs are contrasted in the paragraph’s second sentence: “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.”

Example Question #1 : Comparing And Contrasting In Science Passages

"Comparing Technologies: A Difficult Endeavor" by Matthew Minerd (2014)

Comparisons of technology are often difficult to make, not only because of the rapid pace of improvements but also because of the many new applications that are available as time progresses. If we were to consider the contemporary graphing calculator and the calculation capacities of computing machines from fifty years ago, there would be astounding improvements between these two devices. However, the improvements are not reduced merely to speed improvements. A graphing calculator also has numerous output capacities that far exceed those available much older computers, none of which had the ability to represent their output in any manner even closely resembling that of contemporary devices. Merely consider the display capacities of such a device. These enable users to input many new kinds of information, enabling design engineers to design new hardware functions to match the new means of collecting user input.

The situation is even more obvious when one considers the numerous functions performed by a modern “smartphone.” These devices are equipped with a panoply of features.  With all of these new functions come many new types of computational capabilities as well. In order to process images quickly, specialized hardware must be designed and software written for it in order to ensure that there are few issues with the phone’s operation. Indeed, the whole “real time” nature of telecommunications has exerted numerous pressures on the designers of computing devices. Layers of complexity, at all levels of production and development, are required to ensure that the phone can function in a synchronous manner. Gone are the days of asynchronous processing, when the computer user entered data into a mainframe, only to wait for a period of time before the processing results were provided. Today, even the smallest of digital devices must provide seamless service for users. The effects of this requirement are almost beyond number.

Which of the following best describes the contrast between newer and older calculating devices?

Possible Answers:

Previous calculators had no output capacities whatsoever.

Newer calculators are blazingly faster than older calculating machines.

None of the other answers

They differ both in capabilities as well as overall speed.

Older calculating machines broke down far more frequently than do modern calculators.

Correct answer:

They differ both in capabilities as well as overall speed.

Explanation:

In the selection, there are two key sentences: "However, the improvements are not reduced merely to speed improvements. A graphing calculator also has numerous output capacities that far exceed those available much older computers." The passage marks two points regarding the difference between the older and newer devices. They differ both with regard to speed and their ability to output data. The answer that speaks of having differing "capabilities" captures the distinction in output well enough for our answer. The other answers either bring in data not listed in our passage or are too narrow in scope.

Example Question #1 : Locating Details In Argumentative Science Passages

Adapted from “Introduced Species That Have Become Pests” in Our Vanishing Wild Life, Its Extermination and Protection by William Temple Hornaday (1913)

The man who successfully transplants or "introduces" into a new habitat any persistent species of living thing assumes a very grave responsibility. Every introduced species is doubtful gravel until panned out. The enormous losses that have been inflicted upon the world through the perpetuation of follies with wild vertebrates and insects would, if added together, be enough to purchase a principality. The most aggravating feature of these follies in transplantation is that never yet have they been made severely punishable. We are just as careless and easygoing on this point as we were about the government of the Yellowstone Park in the days when Howell and other poachers destroyed our first national bison herd, and when caught red-handed—as Howell was, skinning seven Park bison cows—could not be punished for it, because there was no penalty prescribed by any law. Today, there is a way in which any revengeful person could inflict enormous damage on the entire South, at no cost to himself, involve those states in enormous losses and the expenditure of vast sums of money, yet go absolutely unpunished!

The gypsy moth is a case in point. This winged calamity was imported at Maiden, Massachusetts, near Boston, by a French entomologist, Mr. Leopold Trouvelot, in 1868 or 69. History records the fact that the man of science did not purposely set free the pest. He was endeavoring with live specimens to find a moth that would produce a cocoon of commercial value to America, and a sudden gust of wind blew out of his study, through an open window, his living and breeding specimens of the gypsy moth. The moth itself is not bad to look at, but its larvae is a great, overgrown brute with an appetite like a hog. Immediately Mr. Trouvelot sought to recover his specimens, and when he failed to find them all, like a man of real honor, he notified the State authorities of the accident. Every effort was made to recover all the specimens, but enough escaped to produce progeny that soon became a scourge to the trees of Massachusetts. The method of the big, nasty-looking mottled-brown caterpillar was very simple. It devoured the entire foliage of every tree that grew in its sphere of influence.

The gypsy moth spread with alarming rapidity and persistence. In course of time, the state authorities of Massachusetts were forced to begin a relentless war upon it, by poisonous sprays and by fire. It was awful! Up to this date (1912) the New England states and the United States Government service have expended in fighting this pest about $7,680,000!

The spread of this pest has been retarded, but the gypsy moth never will be wholly stamped out. Today it exists in Rhode Island, Connecticut, and New Hampshire, and it is due to reach New York at an early date. It is steadily spreading in three directions from Boston, its original point of departure, and when it strikes the State of New York, we, too, will begin to pay dearly for the Trouvelot experiment.

Howell’s story is different from that of Mr. Trouvelot’s in that __________.

Possible Answers:

Howell acted purposely while Trouvelot introduced the moths by accident

Howell acted alone while Trouvelot worked with a group

Howell worked for a zoo while Trouvelot was a scientist

Howell could be punished by law, while Trouvelot could not

Howell sought to capture insects while Trouvelot sought to release them

Correct answer:

Howell acted purposely while Trouvelot introduced the moths by accident

Explanation:

According to the passage, what did Howell do? He was caught skinning bison in Yellowstone National Park and there was no way to punish him, a point about which the author is frustrated. What did Mr. Trouvelot do? He accidentally released gypsy moths into the United States, where they’ve caused a lot of trouble since. Nothing in the passage says that Mr. Trouvelot worked in a group, so we can eliminate the answer “Howell acted alone while Mr. Trouvelot worked with a group.” Similarly, while the passage says that Mr. Trouvelot was a scientist (an entomologist), nothing says that Howell worked for a zoo, so “Howell worked for a zoo while Trouvelot was a scientist” can’t be correct. The author brings up Howell’s story as an example of someone who couldn’t be punished by law for what the author considers an egregiously bad act, so “Howell could be punished by law, while Mr. Trouvelot could not” can’t be correct either. Howell’s story has nothing to do with insects and Mr. Trouvelot released his gypsy moths on accident, so “Howell sought to capture insects while Trouvelot sought to release them” cannot be the correct answer. This leaves us with one answer choice, the correct one: “Howell acted purposely while Trouvelot introduced the moths by accident.”

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