ACT Reading : Comparing and Contrasting Ideas in Natural Science Passages

Study concepts, example questions & explanations for ACT Reading

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Example Questions

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Example Question #46 : 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 does the passage directly compare?

Possible Answers:

The relative warmth of feathers and down as insulating materials

The use of eider down in bedding in North America and in Iceland

The price of down in Iceland and North America

Ducks that nest on the Labrador coast and ducks that nest in Iceland

The nesting habits of hunted and protected ducks

Correct answer:

The nesting habits of hunted and protected ducks

Explanation:

Of the given answer choices, the passage only compares “the nesting habits of hunted and protected ducks.” It does this when the author says, “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.” The price of down is never mentioned in the passage, and while feathers and down are both mentioned, they are not compared. Similarly, the use of eider down in bedding is mentioned, but its use in North America and in Iceland isn’t compared. Finally, while ducks that nest on the Labrador coast and ducks that nest in Iceland are each described, they are not directly compared.

Example Question #1 : Textual Relationships In Science Passages

"Interpreting the Copernican Revolution" by Matthew Minerd (2014)

The expressions of one discipline can often alter the way that other subjects understand themselves. Among such cases are numbered the investigations of Nicolaus Copernicus. Copernicus is best known for his views concerning heliocentrism, a view which eventually obliterated many aspects of the ancient/medieval worldview, at least from the standpoint of physical science. It had always been the natural view of mankind that the earth stood at the center of the universe, a fixed point in reference to the rest of the visible bodies. The sun, stars, and planets all rotated around the earth.

With time, this viewpoint became one of the major reference points for modern life. It provided a provocative image that was used—and often abused—by many people for various purposes. For those who wished to weaken the control of religion on mankind, it was said that the heliocentric outlook proved man’s insignificance. In contrast with earlier geocentrism, heliocentrism was said to show that man is not the center of the universe. He is merely one small being in the midst of a large cosmos. However, others wished to use the “Copernican Revolution” in a very different manner. These thinkers wanted to show that there was another “recentering” that had to happen. Once upon a time, we talked about the world. Now, however, it was necessary to talk of man as the central reference point. Just as the solar system was “centered” on the sun, so too should the sciences be centered on the human person.

However, both of these approaches are fraught with problems. Those who wished to undermine the religious mindset rather misunderstood the former outlook on the solar system. The earlier geocentric mindset did not believe that the earth was the most important body in the heavens. Instead, many ancient and medieval thinkers believed that the highest “sphere” above the earth was the most important being in the physical universe. Likewise, the so-called “Copernican Revolution” in physics was different from the one applied to the human person. Copernicus’ revolution showed that the human point of view was not the center, whereas the later forms of “Copernican revolution” wished to show just the opposite.

Of course, there are many complexities in the history of such important changes in scientific outlook. Nevertheless, it is fascinating to see the wide-reaching effects of such discoveries, even when they have numerous, ambiguous effects.

How are two uses of the image of heliocentrism contrasted in this passage?

Possible Answers:

One calls for detached peace while the other is likely to breed wars.

One implies the insignificance of the human person while the other implies humanity's greatness.

One calls for scientific detachment while the other calls for engagement in the world of culture.

None of the other answers

One is primarily scientific while the other is religious at its core.

Correct answer:

One implies the insignificance of the human person while the other implies humanity's greatness.

Explanation:

The general contrast is between "man, the speck on a rock" and "man, the center of all things." The idea for one view is that the human person is insignificant in comparison to the rest of the universe, which dwarfs his little life on Earth. The other view makes the human person so significant that the study of human life is central.

Example Question #1 : Main Idea, Details, Opinions, And Arguments 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 alone while Trouvelot worked with a group

Howell worked for a zoo while Trouvelot was a scientist

Howell sought to capture insects while Trouvelot sought to release them

Howell could be punished by law, while Trouvelot could not

Howell acted purposely while Trouvelot introduced the moths by accident

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.”

Example Question #2 : Passage Based Questions

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.

For what reason does the author describe the Irish hare as “vegetarian” in the underlined sentence?

Possible Answers:

To encourage the reader to switch to a vegetarian diet

To provide information about the hare's diet that the reader may not know

To help readers empathize with the hare

To contrast the hare with the stoat and the weasel

To provide insight about what food is available in arctic environments

Correct answer:

To contrast the hare with the stoat and the weasel

Explanation:

The underlined sentence is the last sentence of the third paragraph, “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. One could reasonably infer that a hare would be vegetarian, so “To provide information about the hare’s diet that the reader may not know” cannot be the correct answer. The section doesn’t aim to help readers empathize with the hare any more than the stoat and weasel, so “To help readers empathize with the hare” cannot be correct either. The sentence doesn’t specifically encourage the reader to do anything; it is merely providing information about certain animals; so, “To encourage the reader to switch to a vegetarian diet” cannot be correct. “To provide insight about what food is available in arctic environments” doesn’t make sense either, because we are not told about the food specifically available in arctic environments; we can’t even assume that there are only plants available, as the stoat and weasel eat meat. That brings us to the correct answer: “To contrast the hare with the stoat and the weasel.” The word “vegetarian” specifically contrasts with the word “carnivorous” used later in the sentence to describe the stoat and weasel. This contrast mirrors the contrast of defensive and aggressive/defensive color-changing adaptations which the author is discussing in the sentence.

Example Question #683 : Ssat Upper Level Reading Comprehension

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 do Azara, Bullock, and Waterton have in common?

Possible Answers:

They are all types of hummingbirds.

They are all types of birds that eat insects.

They are all scientists who think hummingbirds eat flower nectar.

They are all critics of the writer and disagree with his theory.

They are all scientists who think hummingbirds eat insects.

Correct answer:

They are all scientists who think hummingbirds eat insects.

Explanation:

Azara, Bullock, and Waterton are all mentioned near the beginning of the passage. The author writes, “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.” He then mentioned the following:

(1) "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."

(2) "Bullock, in Mexico, declares that he saw them catch small butterflies, and that he found many kinds of insects in their stomachs."

(3) "Waterton made a similar statement."

The author is suggesting that Azara, Bullock, and Waterton fall into the group of “every close observer of their habits.” The three also make statements about hummingbirds. From this, we can narrow down our answers to three choices: that Azara, Bullock, and Waterton are critics of the author, scientists who think hummingbirds eat insects, or scientists who think hummingbirds eat flower nectar. Nowhere in the passage do the statements made by these writers appear to contradict the author’s opinion, so we can discard the idea that Azara, Bullock, and Waterton are critics of the author. So, are they saying that hummingbirds eat flower nectar or insects? They author says that early observers of hummingbirds thought that they eat flower nectar, but that more recent scientists—like the three quoted—think that they eat insects. The statements made by each also relate to hummingbirds eating insects, so the correct answer is “They are all scientists who think hummingbirds eat insects.”

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