Drawing Generalizations About Natural Science Passages | Reading for ACT PDF Download

Example 1:
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.
Q.  In which of the following would you most expect to find this passage reprinted?
(a) A physics textbook
(b) A how-to manual
(c) A cookbook
(d) An article in a biology magazine
(e) A scholarly report about weasels

Correct Answer is Option (d)
Where would one most likely find this article reprinted? Well, we wouldn’t be likely to find it in “a how-to manual” as it doesn’t explain how to do anything; it conveys information about certain types of animals. Similarly, since it doesn’t discuss physics or have anything to do with cooking, we can ignore the answers “A physics textbook” and “A cookbook.” This leaves us with “A scholarly report about weasels” and “An article in a biology magazine.” At this point we have to consider how the weasel is discussed in the passage—it is discussed very little, only in the context of being compared to the stoat or providing an example of carnivorous animals that change their fur color, along with the stoat. Given that the weasel isn’t the main subject of the passage, “An article in a biology magazine” is the best answer choice.

Example 2:
"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.
Q. This essay is an example of __________.
(a) a narrative
(b) a biography
(c) a persuasive essay
(d) a summary of a book
(e) a research paper

Correct Answer is Option (c)
The answer is "a persuasive essay" because although this paper is about research, it does not cite or include any information coming directly from literature, but rather advocates for the use of a method and supports the assertion with some examples. It is neither a biography nor a narrative because it neither an account on someone’s life nor a fictional story.

Example 3:
"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.
Q. Which of the following could classify the type of people described in the underlined sentence?
(a) Hubristic
(b) Humanitarian
(c) Academic
(d) Scientific
(e) Humanistic

Correct Answer is Option (e)
The people mentioned in this sentence took a very different view from those who thought that the new science showed the "smallness" of the human person. They wanted to say, instead, that it was necessary to have another "recentering," placing the human person at the center of the sciences. Humanism is such a task—though, humanitarianism is not. The latter represents providing aid to help human beings (as in humanitarian action after a major natural disaster).

Example 4:
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.
Q. The kiwi is a bird that lives in New Zealand. New Zealand has no native ground-dwelling predatory animals. The stoat, a ground-dwelling carnivorous mammal, was introduced to New Zealand. Based on the passage, what can you predict happened?
(a) the kiwi population drastically decreased
(b) the kiwis quickly learned to defend themselves against stoats
(c) the kiwi population rose
(d) the stoats could not support themselves in the new environment and died off
(e) None of the other answers

Correct Answer is Option (a)
The situation presented in this question lines up precisely with the dodo’s story in the passage. The kiwi, like the dodo, would thus be unable to defend itself from introduced predators, since like on Mauritius, New Zealand has no native ground-dwelling predators. We can therefore predict that in this situation, the kiwi population would decrease drastically, if not go extinct, so “the kiwi population drastically decreased” is the correct answer. (In fact, the kiwi and stoat situation actually happened in New Zealand. While the kiwi remains a living species, New Zealand has had to work very hard to protect it from stoats.)

Example 5:
"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.
Q. Which of the following provides an example of the main idea asserted in the first paragraph?
(a) Religion constantly wanes with the rise of science.
(b) The interest in science only arises once agriculture reaches a certain point of fixity.
(c) The Pythagorean theorem is based upon the constant relationship of the sides of a right triangle to its hypotenuse.
(d) The fluctuation of coloration within a species is rather minimal.
(e) None of the other answers

Correct Answer is Option (c)
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 6:
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.
Q. 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?
(a) More evidence as to why Grisebach’s theory is the correct one
(b) A summary of a paper the author wishes to publish on the topic being discussed
(c) Further consideration of the theory of the writer quoted in the first paragraph
(d) Praise of the useful nature of Hooker’s research
(e) A discussion of the historical uses of alpine plants

Correct Answer is Option (a)
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 7:
Adapted from Common Diseases of Farm Animals by R. A. Craig (1916, 2nd ed.)
The common bot-fly of the horse (G. equi) has a heavy, hairy body. Its color is brown, with dark and yellowish spots. The female fly can be seen during the warm weather, hovering around the horse, and darting toward the animal for the purpose of depositing the egg. The color of the egg is yellow, and it adheres firmly to the hair. It hatches in from two to four weeks, and the larva reaches the mouth through the animal licking the part. From the mouth, it passes to the stomach, where it attaches itself to the gastric mucous membrane. Here it remains until fully developed, when it becomes detached and is passed out with the feces. The third stage is passed in the ground. This takes place in the spring and early summer and lasts for several weeks, when it finally emerges a mature fly.
The bot-fly of the ox (H. lineata) is dark in color and about the size of a honey-bee. On warm days, the female may be seen depositing eggs on the body of the animal, especially in the region of the heels. This seems to greatly annoy the animal, and it is not uncommon for cattle to become stampeded. The egg reaches the mouth through the animal licking the part. The saliva dissolves the shell of the egg and the larva is freed. It then migrates from the gullet, wanders about in the tissue until finally it may reach a point beneath the skin of the back. Here the larva matures and forms the well-known swelling or warble. In the spring of the year it works out through the skin. The next stage is spent in the ground. The pupa state lasts several weeks, when the mature fly issues forth.
The bot-fly of sheep (O. ovis) resembles an overgrown house-fly. Its general color is brown, and it is apparently lazy, flying about very little. This bot-fly makes its appearance when the warm weather begins, and deposits live larvae in the nostrils of sheep. This act is greatly feared by the animals, as shown by their crowding together and holding the head down. The larva works up the nasal cavities and reaches the sinuses of the head, where it becomes attached to the lining mucous membrane. In the spring, when fully developed, it passes out through the nasal cavities and nostrils, drops to the ground, buries itself, and in from four to six weeks develops into the mature fly.
SYMPTOMS OF BOT-FLY DISEASES.—The larvae of the bot-fly of the horse do not cause characteristic symptoms of disease. Work horses that are groomed daily are not hosts for a large number of "bots," but young and old horses that are kept in a pasture or lot and seldom groomed may become unthrifty and "pot bellied," or show symptoms of indigestion.
Cattle suffer much pain from the development of the larva of the H. lineata. During the spring of the year, the pain resulting from the presence of the larvae beneath the skin and the penetration of the skin is manifested by excitement and running about. Besides the loss in milk and beef production, there is a heavy yearly loss from the damage to hides.
The life of the bot-fly of sheep results in a severe catarrhal inflammation of the mucous membrane lining the sinuses of the head, and a discharge of a heavy, pus-like material from the nostrils. The irritation produced by the larvae may be so serious at times as to result in nervous symptoms and death. 

Q. Which of the following sentences best summarizes the fourth paragraph?
(a) Young and old horses are not consistently attacked by the bot-fly, but adult horses are continuously attacked by the bot-fly.
(b) A horse must be groomed twice a year to avoid the symptoms of bot-fly larvae.
(c) If a horse shows symptoms of bot-fly larvae, then it should be groomed, although this does not apply to very young or very old animals.
(d) Horses show few symptoms and are more protected if they are groomed, unlike those left in pastures.
(e) Horses with matted hair are less susceptible to an infestation as they lick themselves less frequently.

Correct Answer is Option (d)
The paragraph states three things: firstly, bot-fly larvae “do not cause characteristic symptoms of disease”; secondly, “horses that are groomed daily are not hosts for a large number of 'bots'”; and thirdly, “young and old horses that are kept in a pasture or lot and seldom groomed may become unthrifty and 'pot bellied,' or show symptoms of indigestion.” From this, we can conclude that the correct answer is "Horses show few symptoms and are more protected if they are groomed, unlike those left in pastures."