HSPT Reading : Comparing and Contrasting in Natural Science Passages

Study concepts, example questions & explanations for HSPT Reading

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Example Questions

Example Question #1 : Comparing And Contrasting In Natural Science Passages

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

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

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

One of the main differences between an ostrich and a rail, according to the passage, is __________.

Possible Answers:

ostriches are smaller than rails

ostriches live in grassy areas whereas rails live in the desert

ostriches run over open terrain, and rails run through thick grass 

ostriches are living things whereas rails are inanimate objects

ostriches use their running abilities to catch prey, whereas rails use their running abilities to avoid predators

Correct answer:

ostriches run over open terrain, and rails run through thick grass 

Explanation:

Ostriches and rails are discussed in the first paragraph. The author says that “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.” The passage then goes on to detail how rails have thin bodies that allow them to dart through the grass. This means that the correct answer is “ostriches run over open terrain whereas rails run through thick grass.” 

The passage is describing the rail, a type of bird, and not using the word “rail” to describe part of a train track or a barrier on an elevated area, so “ostriches are living things whereas rails are inanimate objects” cannot be correct. Ostriches are never said to be smaller than rails or predators, so neither “ostriches are smaller than rails” nor “ostriches use their running abilities to catch prey, whereas rails use their running abilities to avoid predators” can be correct. Finally, rails are said to live in areas containing and have adapted to “thickly-growing vegetation” and ostriches are said to have developed a different adaptation suited to “open country,” so “ostriches live in grassy areas whereas rails live in the desert” cannot be correct either.

Example Question #7 : Comparing And Contrasting Ideas In Natural Science Passages

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

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

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

How does the second paragraph relate to the first paragraph?

Possible Answers:

The first paragraph describes flightless birds that learned to defend themselves from predators by fleeing them; the second paragraph describes a flightless bird that did not adapt in this way.

The first paragraph describes birds people eat; the second describes birds people do not eat.

The first paragraph describes a type of flightless birds that has gone extinct; the second describes species of flightless birds that are still living.

The first paragraph provides a personal anecdote while the second paragraph provides historical information.

The first paragraph discusses predators of flightless birds, the second describes prey of flightless birds.

Correct answer:

The first paragraph describes flightless birds that learned to defend themselves from predators by fleeing them; the second paragraph describes a flightless bird that did not adapt in this way.

Explanation:

Examining the two paragraphs, one can find that the first one talks about ostriches and rails, two types of flightless birds that adapted in specific ways to be good at fleeing predators. The second paragraph tells the story of the dodo, a flightless bird that did not have time to develop such adaptations. From here, we can pick out the correct answer: “The first paragraph describes flightless birds that learned to defend themselves from predators by fleeing them; the second paragraph describes a flightless bird that did not adapt in this way.”

As for the other answer choices, nothing in the passage discusses people eating birds, so we can ignore the answer choice “The first paragraph describes birds people eat; the second describes birds people do not eat.” The answer choice “The first paragraph describes a type of flightless birds that has gone extinct; the second describes species of flightless birds that are still living” would be correct if it flipped around the paragraphs to which it refers, but as it is written, it is incorrect. The passage doesn’t say anything about the predators of flightless birds in the first paragraph or the prey of flightless birds in either paragraph, so “The first paragraph discusses predators of flightless birds, the second describes prey of flightless birds” cannot be correct, and since the first paragraph does not provide a personal anecdote, “The first paragraph provides a personal anecdote while the second paragraph provides historical information” cannot be correct either.

Example Question #1 : Compare / Contrast

Adapted from "Errors in Our Food Economy" in Scientific American Supplement No. 1082 Vol. XLII (September 26th, 1896)

Scientific research, interpreting the observations of practical life, implies that several errors are common in the use of food.

First, many people purchase needlessly expensive kinds of food, doing this under the false impression that there is some peculiar virtue in the costlier materials, and that economy in our diet is somehow detrimental to our dignity or our welfare. And, unfortunately, those who are most extravagant in this respect are often the ones who can least afford it.

Secondly, the food which we eat does not always contain the proper proportions of the different kinds of nutritive ingredients. We consume relatively too much of the fuel ingredients of food, such as the fats of meat and butter, and the starch which makes up the larger part of the nutritive material of flour, potatoes, sugar, and sweetmeats. Conversely, we have relatively too little of the protein of flesh-forming substances, like the lean of meat and fish and the gluten of wheat, which make muscle and sinew and which are the basis of blood, bone and brain.

Thirdly, many people, not only the well-to-do, but those in moderate circumstances, use needless quantities of food. Part of the excess, however, is simply thrown away with the wastes of the table and the kitchen; so that the injury to health, great as it may be, is doubtless much less than if all were eaten. Probably the worst sufferers from this evil are well-to-do people of sedentary occupations.

Finally, we are guilty of serious errors in our cooking. We waste a great deal of fuel in the preparation of our food, and even then a great deal of the food is very badly cooked. A reform in these methods of cooking is one of the economic demands of our time.

It is the author's opinion that we should consume less/fewer __________ and more __________.

Possible Answers:

lean meat . . . fish

fish . . . butter

wheat gluten . . . potatoes

sugar . . . fat

sweetmeats . . . lean meat

Correct answer:

sweetmeats . . . lean meat

Explanation:

In the third paragraph, the author states, "We consume relatively too much of the fuel ingredients of food, such as the fats of meat and butter, and the starch which makes up the larger part of the nutritive material of flour, potatoes, sugar, and sweetmeats. Conversely, we have relatively too little of the protein of flesh-forming substances, like the lean of meat and fish and the gluten of wheat, which make muscle and sinew and which are the basis of blood, bone and brain." So, he or she thinks we should consume less fatty meat, butter, and starch in the form of flour, potatoes, sugar, and sweetmeats. This allows us to narrow down our answer choices to "sweetmeats . . . lean meat" and "sugar . . . fat." So, does the author think we should eat more lean meat, or more fat? The author says in the second sentence that we should eat more lean meat, fish, and wheat gluten, so "sweetmeats . . . lean meat" is the correct answer. The author mentions fat when discussing things of which we consume too much in the first sentence.

Example Question #1 : Comparing And Contrasting In Natural Science Passages

"Cacti" by Ami Dave (2013)

Cacti are plants suited to the desert, and we must always keep this factor in mind when growing ornamental cacti in our gardens, for it helps us provide cacti with conditions that allow them to survive and thrive. For example, a cactus should never be watered over its body, as it will start to rot. This is because it is covered with a waxy coating which prevents water loss through evaporation. When one waters the cactus over its body, the waxy coating is washed away and the plant begins to rot. The amount of water that one must supply to the cactus is very much dependent upon the season and upon the climate of the place. During the summer season one should water cacti every four days, whereas in the rainy season, once every fifteen days is quite enough.

Cacti need a minimum of two and a half hours of sunlight per day; however, they should not be kept in the sun all day because they may wrinkle when exposed to too much bright sunlight. Unlike other plants, cacti produce carbon dioxide during the day and oxygen during the night, so they are ideal plants to be kept in bedrooms to freshen up the air at night.

If a cactus is to thrive and prosper, the size of the pot in which it is grown needs to be monitored carefully. The pot should always be a little smaller than the plant itself because it is only when the plant has to struggle to survive that it will thrive. If the pot is too spacious and the plant does not need to struggle, chances are that the cactus will die. Similarly, if a cactus shows no signs of growth, stop watering it. Watering should be resumed only when the plant begins to grow again.

The substrata of a cactus pot is ideally composed of pieces of broken bricks at the bottom, followed by a layer of charcoal above the bricks, and then coarse sand and pebbles above the charcoal. Leaf mould is the best manure.

Grafting cacti is very simple. A very small piece of the cactus plant should be stuck with tape to the plant that needs grafting. The smaller the piece, the easier it is to graft. To reproduce cacti, one has to simply cut off a piece of the cactus, allow it to dry for a few days, and then place it over the cacti substrate. It will automatically develop roots.

It is very easy to differentiate between cacti and other plants that look like cacti. All cacti have fine hair at the base of each thorn. The so-called “thorns” are in fact highly modified leaves which prevent loss of water through transpiration. If one ever gets pricked by cacti thorns, one should take tape, place it over the area where the thorns have penetrated the skin, and then peel it off. All of the thorns will get stuck to the tape and will be removed.

The development of a new cactus from a graft is similar to what other biological phenomenon?

Possible Answers:

The birth of a genetically unique organism from an egg

A nematode worm that develops into two separate organisms when cut in half

A lizard that regrows its tail

An unsuccessful kidney transplant

A cut that successfully heals

Correct answer:

A nematode worm that develops into two separate organisms when cut in half

Explanation:

The passage discusses how grafting is a relatively simple procedure, and all that one must do is cut off a piece of the cactus and place it in an environment that supports its growth: the new cactus will develop roots. This is most similar to when a worm develops into a new organism when part of it is cut off. A lizard regrowing its tail is not similar to a graft, since the original organism simply regains the part that it lost. In the same vein, a cut that heals also involves an organism healing itself, not splitting apart to form a new organism. Birth from an egg or a failed organ transplant are not similar to the effects of a cactus graft.

Example Question #1 : Comparing And Contrasting In Natural Science Passages

Adapted from An Introduction to Astronomy by Forest Ray Moulton (1916 ed.)

The ancient Greeks, at a period four or five hundred years preceding the common era, definitely undertook to find from systematic observation how celestial phenomena follow one another. They determined very accurately the number of days in the year, the period of the moon's revolution, and the paths of the sun and the moon among the stars; they correctly explained the cause of eclipses and learned how to predict them with a considerable degree of accuracy; they undertook to measure the distances to the heavenly bodies, and to work out a complete system that would represent their motions. The idea was current among the Greek philosophers that the earth was spherical, that it turned on its axis, and, among some of them, that it revolved around the sun. They had true science in the modern acceptance of the term, but it was largely confined to the relations among celestial phenomena.

The conception that the heavens are orderly, which they definitely formulated and acted on with remarkable success, has been extended, especially in the last two centuries, so as to include the whole universe. The extension was first made to the inanimate world and then to the more complicated phenomena associated with living beings. Every increase in carefully recorded experience has confirmed and strengthened the belief that nature is perfectly orderly, until now every one who has had an opportunity of becoming familiar with any science is firmly convinced of the truth of this principle, which is the basis of all science.

Which best describes the contrast between modern and ancient science?

Possible Answers:

While ancient science focused mainly on the heavens, contemporary science is much more biological.

While modern science has many branches, ancient science had a more limited number of subjects that it studied.

While ancient science investigated visible bodies, contemporary science is concerned with many realities that would have been invisible in past ages.

None of the other answers

The two have very little in common at all.

Correct answer:

While modern science has many branches, ancient science had a more limited number of subjects that it studied.

Explanation:

This selection does not do much to contrast the two sciences, as it is focusing on the character of Greek science in general, particularly its concern with celestial bodies and their motions. However, at the end of the first paragraph, there is a helpful sentence: "They had true science in the modern acceptance of the term, but it was largely confined to the relations among celestial phenomena." This implies that they had only one "real" branch of science, namely that which was "confined to the relations among celestial phenomena." The implication is that in contrast with this single science, modernity has a number of different sciences.

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.

They differ both in capabilities as well as overall speed.

None of the other answers

Newer calculators are blazingly faster than older calculating machines.

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 : Comparing And Contrasting In Natural Science Passages

Adapted from “Some Strange Nurseries” by Grant Allen in A Book of Natural History (1902, ed. David Starr Jordan)

Among the larger lizards, a distinct difference may be observed between the American alligator and its near ally, the African crocodile. On the banks of the Mississippi, the alligator lays a hundred eggs or thereabouts, which she deposits in a nest near the water’s edge, and then covers them up with leaves and other decaying vegetable matter. The fermentation of these leaves produces heat and so does for the alligator’s eggs what sitting does for those of hens and other birds: the mother deputes her maternal functions, so to speak, to a festering heap of decomposing plant-refuse. Nevertheless, she loiters about all the time to see what happens, and when the eggs hatch out, she leads her little ones down to the river, and there makes alligators of them. This is a simple nursery arrangement of the big lizards.

The African crocodile, on the other hand, does something different, and takes greater care for the safety of its young. It lays only about thirty eggs, but these it buries in warm sand, and then lies on top of them at night, both to protect them from attack and to keep them warm during the cooler hours. In short, it sits upon them. When the young crocodiles within the eggs are ready to hatch, they utter an acute cry. The mother then digs down to the eggs, and lays them freely on the surface, so that the little reptiles may have space to work their way out unimpeded. This they do by biting at the shell with a specially developed tooth; at the end of two hours’ nibbling they are free, and are led down to the water by their affectionate parent. In these two cases we see the beginnings of the instinct of hatching, which in birds has become almost universal.

How does the author of this passage compares the American alligator and the African crocodile in terms of __________.

Possible Answers:

how closely-related each type of animal is to birds

how caring and protective the mothers are of their offspring

how much food is needed to keep the young of the animal alive

None of these answers is accurate.

how uncaring and protective the mothers are of their offspring

Correct answer:

how uncaring and protective the mothers are of their offspring

Explanation:

From the context of the whole of this passage, which is discussing the differences between how alligators and crocodiles care for their young, it is clear that the author believes that the American alligator is far less protective of its young than the African crocodile is, so the two animals are being compared in terms of "how caring and protective the mothers are of their young."

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