ACT Reading : Determining Context-Dependent Meanings of Phrases and Clauses in Natural Science Passages

Study concepts, example questions & explanations for ACT Reading

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Example Questions

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Example Question #161 : Natural Sciences

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.

What does the author mean in using the underlined phrase “kept green”?

Possible Answers:

kept literally alive

kept obscure

kept fresh and current

kept feeling ill or worried

kept envious

Correct answer:

kept fresh and current

Explanation:

 The phrase “keep green” appears in the following sentence in the passage’s second paragraph:

“[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.” 

From this context, we can tell that “kept green” is not being used to refer to the dodo itself, as at this point, the passage is discussing the “memory” that remains of the dodo as an extinct species. This means that “kept literally alive” cannot be correct. Nothing in the sentence suggests that the phrase means “kept envious, “”kept feeling ill or worried,” or “kept obscure.” However, the drawings, descriptions, remains, and proverb all keep the dodo’s memory fresh and current, so “kept fresh and current” is the correct answer.

Example Question #161 : Natural Sciences

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 best restates the meaning of the underlined phrase “as the population increased in numbers, the quantity thus furnished was insufficient”?

Possible Answers:

As the number of citizens of New England increased, the desirability of eider down decreased

As the number of Icelandic citizens increased, the populations of Icelandic ducks decreased

As the population of New England settlers increased, the amount of eider down collected was no longer enough

As the population of Icelandic ducks increased, their food sources began to deplete

As the number of ducks increased, the number of eggs they laid became no longer satisfactory

Correct answer:

As the population of New England settlers increased, the amount of eider down collected was no longer enough

Explanation:

In order to answer this question correctly, you have to consider the context in which this phrase appears: “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.” It only makes sense for “population” to refer to a population of people, not of ducks, as the sentence concludes by saying “the people sought a larger supply in the vast colonies of ducks and geese along the Labrador coast.” They would not need to seek out a larger supply of ducks and geese if the population of ducks and geese was increasing. Knowing this, we can discard the answer choices “As the number of ducks increased, the number of eggs they laid became no longer satisfactory” and “As the population of Icelandic ducks increased, their food sources began to deplete.” The sentence is only discussing New England settlers; it does not mention Iceland. So, “As the number of Icelandic citizens increased, the populations of Icelandic ducks decreased” cannot be correct either. This leaves us with two answer choices: “As the number of citizens of New England increased, the desirability of eider down decreased,” and “As the population of North America increased, the amount of eider down collected was no longer enough.” The important distinction made between these two answer choices hinges on the meaning of the word “quantity.” “Quantity” means number of, so the correct answer is “As the population of New England increased, the amount of eider down collected was no longer enough.” If you read the sentence quickly and confused quantity with “quality,” which means how good something is, you may have picked the other answer choice. It’s important to read carefully, especially when answering questions that deal with paraphrasing!

Example Question #92 : Passage Meaning And Construction

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.

Which of the following best paraphrases the underlined sentence, “Every introduced species is doubtful gravel until panned out”?

Possible Answers:

One can’t tell whether an introduced species will be helpful or harmful until it is actually introduced.

One should never move a species from its natural environment into a new environment for fear of the consequences.

Species that live underground should be carefully examined before being moved into new environments.

An invasive species can cause beneficial effects to its new environment as well as harmful ones.

Species that live in gravel are usually harmful when placed in new environments.

Correct answer:

One can’t tell whether an introduced species will be helpful or harmful until it is actually introduced.

Explanation:

Here, the author is using figurative language to describe introduced species. He metaphorically calls them “doubtful gravel until [they are] panned out.” Because he’s not speaking literally, this sentence has nothing to do with the ground or gravel itself, so we can eliminate the answer choices “Species that live underground should be carefully examined before being moved into new environments” and “Species that live in gravel are usually harmful when placed in new environments.”

What is the author getting at with his metaphor? Panning rocks and dirt allows miners to separate out valuable minerals from other matter. Think of miners “panning for gold”—it’s the same principle, except here, the author is speaking of it as applying to gravel. By calling the gravel “doubtful,” the author is expressing that you don’t know what you’re going to get with it before you “pan it out” and see if there is anything valuable in it. Applying this thinking to invasive species, the author is therefore saying that “one can’t tell whether an introduced species will be helpful or harmful until it is actually introduced.” 

If you didn’t know what panning gravel was, you could still solve this question by narrowing down your answer choices. For instance, nowhere in the passage are the beneficial effects of introduced species discussed, though the author discusses this in a previous chapter of his book. Because they’re not mentioned in the passage, we can discard the answer choice “An invasive species can cause beneficial effects to its new environment as well as harmful ones.” This is definitely not what the indicated sentence is saying; if we replaced the sentence with this answer choice, the logic of the paragraph wouldn’t make any sense.

As for the remaining answer choice, “One should never move a species from its natural environment into a new environment for fear of the consequences,” it cannot be correct because in the sentence before the one on which this question focuses, the author writes, “The man who successfully transplants or ‘introduces' into a new habitat any persistent species of living thing assumes a very grave responsibility.” Note that he doesn’t say that this should never be done; he just implies that it could go very badly. It wouldn’t make much sense if in the next sentence, the author said this should never be done. It seems more logical that he would have led with that statement, it being the stronger of the two.

Example Question #1 : Specific Phrases And Sentences In Natural Science Passages

"The Place of Lesion Studies in Neuroscience" by Samantha Winter (2013)

It’s easy to forget that the study of neuroscience originated from non-normalized, non-statistically appraised methods like lesion studies. It’s equally easy, with the advent of sophisticated technology, to render such a method obsolete. A small group of neuroscientists today make a case for the reinstitution of lesion studies—the study of abnormal brains with damaged regions in order to better understand the brain—into the twenty-first-century cognitive neuroscience realm. Their suggestion is bold, but their argument is justified.

Cognitive neuroscientists advocate for the use of convergent methods. Many of them argue that with the limitations of our existing techniques, convergent evidence is imperative for sound research. If this is the case, why ignore a method that has potential for implying causality in a domain dominated by correlational research? Rather than advocating for a single method, neuroscientists should take their own advice and use convergent techniques. Sound research should combine a variety of techniques to examine both causal relationships and overcome the individual shortcomings of each method through the use of many.

Lesion studies are also significantly more beneficial now than they were in earlier times. Neuroimaging methods have enhanced our understanding of what contributes to the brain problems most often encountered, and more refined experiments have been developed to confirm the findings from the more unreliable lesion studies. This transformation allows lesion studies to be included alongside the other systems as a mechanism for understanding the human brain.

The underlined selection "to render such a method obsolete" most closely means __________.

Possible Answers:

to make lesion studies more important

to question the existence of lesion studies

to redesign lesion studies

to make neuroscience the most important field of science

to consider lesion studies outdated

Correct answer:

to consider lesion studies outdated

Explanation:

The answer is obsolete, because it means outdated or archaic, and the word “method” refers back to the prior sentence, “methods like lesion studies,” thus stating that the some consider these lesion studies outdated. Because of the meaning of the word obsolete, "to make lesion studies more important" is incorrect. This statement does not refer to the field of neuroscience, therefore "to make neuroscience the most important field of science" is incorrect, and there is no consideration in the paper (and certainly not in the first few sentences) that lesions do not exist, just how valuable they are to the field of study – therefore "to question the existence of lesion studies" is incorrect.

Example Question #1 : Language In Science Passages

Adapted from 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)

The examples of protective resemblance so far quoted are mostly permanent adaptations to one particular sort of surrounding. There are, however, numerous animals which possess the power of adjusting their color more or less rapidly so as to harmonize with a changing environment.

Some of the best known of these cases are found among those mammals and birds that inhabit countries more or less covered with snow during a part of the year. A good instance is afforded by the Irish or variable hare, which is chiefly found in Ireland and Scotland. In summer, this looks very much like an ordinary hare, though rather grayer in tint and smaller in size, but in winter it becomes white with the exception of the black tips to the ears. Investigations that have been made on the closely allied American hare seem to show that the phenomenon is due to the growth of new hairs of white hue. 

The common stoat is subject to similar color change in the northern parts of its range. In summer it is of a bright reddish brown color with the exception of the under parts, which are yellowish white, and the end of the tail, which is black. But in winter, the entire coat, save only the tip of the tail, becomes white, and in that condition the animal is known as an ermine. A similar example is afforded by the weasel. The seasonal change in the vegetarian Irish hare is purely of protective character, but in such an actively carnivorous creature as a stoat or weasel, it is aggressive as well, rendering the animal inconspicuous to its prey.

The phrase “harmonize with,” underlined in the first paragraph, most closely means __________.

Possible Answers:

conduct

parallel

systematize

match

sing in harmony with

Correct answer:

match

Explanation:

The phrase “harmonize with” appears in this sentence in the first paragraph: “There are, however, numerous animals which possess the power of adjusting their color more or less rapidly so as to harmonize with a changing environment.” While “harmonize with” can mean “sing in harmony with,” this meaning doesn’t make sense in the context of the passage’s sentence. “Parallel,” “systematize,” and “conduct” don’t make sense either—only “match” makes sense, so it is the correct answer.

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