McGraw-Hill Education ACT 2017 (2016)



35 Minutes – 40 Questions

DIRECTIONS: This test includes seven passages, each followed by several questions. Read the passage and choose the best answer to each question. After you have selected your answer, fill in the corresponding bubble on your answer sheet. You should refer to the passages as often as necessary when answering the questions. You may NOT use a calculator on this test.


Certain types of insects are abundant in each region of the United States. These insects have a profound impact on the indigenous (native) plant life that grows in each region. If foreign insects are introduced into a region, the plant life can be devastated. Two experiments were performed to study the effect that foreign insects can have on indigenous plants of a certain region.

Experiment 1

A botanist placed 3 indigenous plant species in a local greenhouse. For 3 weeks no insects were allowed to enter. The amount of plant growth was recorded at the end of 3 weeks. For the next 3-week period, only indigenous insects were allowed near the plants. The plants’ growth was recorded again after 6 weeks. In the last 3-week period the native insects were removed, and foreign insects were introduced. The growth of the plants was recorded at the end of the 9-week period. The results are shown in Table 1.


Experiment 2

A botanist placed 3 indigenous plant species in a greenhouse as in Experiment 1. This time, foreign insects were introduced from the start of the experiment. The plants’ growth was recorded over the same 9-week period. The results are shown in Table 2.


Information on the insect types used is given in Table 3.


1.   The results of Experiment 2 indicate that all of the plants experienced a decline in growth rate during what time frame?

A.  0–3 weeks

B.  3–6 weeks

C.  6–9 weeks

D.  No decline in growth rate was recorded.

2.   Which plant type was NOT studied in Experiment 1?

F.  Fragrant sumac

G.  Aphid

H.  Big blue stem

 J.  Yaupon

3.   According to Experiments 1 and 2, which plant type experienced the most total growth during weeks 6–9?

A.  Big blue stem

B.  Fragrant sumac

C.  Yaupon

D.  Each plant type experienced the same total growth.

4.   Based on the experiments, which of the following pairs of insects most likely had the greatest effect on limiting plant growth?

F.  Mantid, Dragonfly

G.  Mosquito, Grasshopper

H.  Grasshopper, Aphid

 J.  Aphid, Mosquito

5.   Based on the results of Experiments 1 and 2, which of the following statements is most accurate?

A.  Foreign insects have little to no impact on indigenous plant growth.

B.  Native insects can help to increase growth in some plants.

C.  Indigenous plant life is most affected by native insects.

D.  Foreign insects cannot survive in local greenhouses.


Two scientists discuss the possibility of predicting hurricanes and the paths that the hurricanes will take.

Scientist 1

Hurricane prediction can be made in real time based on certain events. For example, winds shift inland and increase in speed up to 2 days before a hurricane makes landfall. The tidal volume can increase by 30% one day before a hurricane makes landfall. Animals are sometimes seen exhibiting strange behavior as far ahead as weeks before a hurricane makes landfall. Certain instruments such as seismographs can detect the ground vibrations that occur while a hurricane is making its way across the ocean. The direction of the vibrations’ origin allows the scientific community to predict the path that the hurricane will take. Historical evidence is also a valuable predictive tool.

Scientist 2

Hurricane prediction cannot be made in real time. Shifts in wind speed and direction on shore have not been proven to have any effect on the direction or time of landfall. Only when a hurricane makes landfall can the seismograph be used to determine direction of the hurricane’s path. Tidal volume is constantly changing for many different reasons and, therefore, cannot be used as a predictive tool. Previous records of hurricane patterns are a much more accurate way to predict when and where a hurricane will occur. Once enough information has been derived from past hurricanes, predictive measures can be developed.

6.   Which of the following ideas about hurricane prediction is implied by Scientist 2?

F.  Present-day predictive tools are not based upon enough past data to be accurate.

G.  Hurricane prediction will never be possible.

H.  Animal behavior is proving itself to be the best possible hurricane predictor available.

 J.  Scientific tools are the only things that can predict a hurricane’s location and path.

7.   A scientific article is published that states that the study of animal behavior is useful in predicting hurricanes. Which of the scientists’ viewpoints, if any, is (are) supported by this statement?

A.  Scientist 1

B.  Scientist 2

C.  Both Scientist 1 and Scientist 2

D.  Neither Scientist 1 nor Scientist 2

8.   Increased seismic activity has been recorded along the coastline of Florida. With which of the following statements about the finding would Scientist 1 agree?

F.  Tidal volume is likely to decrease by 30%.

G.  A seismograph is only useful for predicting earthquake activity.

H.  Seismic activity has little to do with when or where the hurricane will travel.

 J.  A hurricane could be moving across the ocean.

9.   Which statement, if true, would support both scientists’ viewpoints?

A.  Historical hurricane data has recently been used to predict the path a hurricane will take.

B.  Seismic activity is predictive of both when and where the hurricane will make landfall.

C.  Tidal volume cannot be used as a predictive tool because it is constantly changing.

D.  Tidal volume and wind direction are not accurate or useful predictors of hurricanes.

10.   What would be the best way to test the claims made by Scientist 2?

F.  Compare current hurricane data with the past data in the same area.

G.  Monitor seismic activity along the coastline.

H.  Keep a record of the tidal volume before a hurricane makes landfall.

 J.  Track animal behavior before the arrival of the hurricane.

11.   As they approach land, tropical storms would bring increased winds before the storms attain hurricane status. If early identification of tropical storms could help to predict hurricanes, such information would most likely:

A.  strengthen Scientist 1’s viewpoint.

B.  weaken Scientist 1’s viewpoint.

C.  weaken the viewpoints of both Scientist 1 and Scientist 2.

D.  have no effect on either scientist’s viewpoint.

12.   According to Scientist 2, which of the following is a major flaw in Scientist 1’s theory on hurricane prediction?

F.  Information gathered from past hurricanes could be useful.

G.  Seismographs are used to monitor the path that a hurricane takes.

H.  Historical data is accurate.

 J.  Tidal volume increases can be used to predict hurricanes.


One of the primary physical properties of matter is volume. Solids, liquids, and gases, which make up three of the observed states of matter, can easily be recognized by certain physical characteristics, such as volume. The effect of compression (the ability of pressure to alter the volume of matter) is called compressibility.

Gases are highly compressible because the volume of gas is very responsive to changes in pressure. A very small change in pressure can considerably alter the volume of a gas. On the other hand, most liquids and solids have a higher density and, therefore, a very low compressibility. Changes in pressure are measured in atmospheres (atm).

Figure 1 shows quantities of pressure and volume along an isotherm. An isotherm is a line of constant temperature. One can determine the compressibility by noting the relationship between the change in pressure and the change in volume. Portions of the line where large changes in pressure result in only minimal changes in volume signify low compressibility. Portions of the line where small changes in pressure result in a significant change in volume suggest high compressibility.


Figure 1

Divers must be careful to rise slowly in the water, or else nitrogen absorbed into the diver’s cells may expand, creating painful and dangerous bubbles. This is called decompression sickness, but is more commonly known as “the bends.”

Figure 2 shows the air pressure (in atm) at different depths of water in meters (m).


Figure 2

Underwater, pressure can be felt in certain air spaces in the body, such as the lungs, sinuses, and ear canals. Air is a gas with a low density and high compressibility. Therefore, the volume of air inside the body is dependent on the space that contains it. The volume of air in flexible spaces, such as the lungs or sinuses, is reduced or expanded proportionate to the pressure. For example, a diver moving from 10 meters underwater to the surface will have the volume of air in his or her lungs double.

13.   According to Figure 2, what is the air pressure at 65 meters below the surface?

A.  4.5 atm

B.  5.5 atm

C.  6.0 atm

D.  7.0 atm

14.   According to the data provided, one could generalize that the volume of air in the lungs:

F.  increases as one moves closer to the surface.

G.  increases as temperature decreases.

H.  increases as the air pressure increases.

 J.  increases as one moves deeper underwater.

15.   According to the passage, as compared to gases, which of the following statements is true?

A.  Solids have lower compressibility because of their higher density.

B.  Liquids have lower compressibility because of their lower density.

C.  Both liquids and solids have higher compressibility because of their lower density.

D.  Both liquids and solids have lower compressibility because of their lower density.

16.   The information provided indicates that compressibility can be a problem when diving. Which of the following statements would best explain why this is true?

F.  Atmospheric pressure is nonexistent below the water’s surface.

G.  As you descend underwater, the gas in the body expands quickly.

H.  Moving to the surface causes the gas in the body to expand very quickly.

 J.  Moving to the surface causes the gas in the body to compress very quickly.

17.   According to Figure 1, compressibility is lowest where:

A.  temperature is lowest and pressure is the lowest.

B.  temperature is highest and pressure is the lowest.

C.  the change in pressure is less than the change in volume.

D.  the change in pressure is greater than the change in volume.


Studies have shown that acid rains damage the skin pigmentation in certain species of salamanders. This results in an inability to change color and be protected from predators. Increased predation accounts for a decrease in the percentage of salamanders that survive to adulthood. Certain species of salamander have developed weather-protective behavior that has an effect on their relative ability to avoid skin damage (Table 1).


Figure 1 shows the percentage of each species that generally survive to adulthood.


Figure 1

18.   Based on the information in Figure 1, salamanders from which species are most likely to survive to adulthood despite the presence of acid rain?

F.  Species A

G.  Species D

H.  Species E

 J.  Species G

19.   According to the data in Figure 1, which of the following species showed the greatest difference between survival with no exposure to acid rain and survival with exposure to acid rain?

A.  Species B

B.  Species C

C.  Species E

D.  Species G

20.   Researchers have recently discovered a new species of salamander that exhibits the weather-protective behavior of burrowing deep underground. Based on the information in Table 1, the salamander’s relative ability to avoid skin damage is most likely which of the following?

F.  <0.1

G.  0.1

H.  0.5

 J.  >1.5

21.   According to the information in Table 1, for all of the species shown, as the relative ability to avoid skin damage due to acid rain increases, exposure to acid rain generally:

A.  increases only.

B.  decreases only.

C.  increases then decreases.

D.  decreases then increases.

22.   Based on the information in Table 1 and Figure 1, the species of salamander with the lowest percentage surviving to adulthood:

F.  seeks protection inside trees.

G.  seeks protection inside buildings.

H.  seeks protection under plants.

 J.  does not seek protection.


Some mountains have been shown to lose rock or sediment due to seasonal snow melting. Figure 1 shows mountain composition, mountain peak section heights in meters (m), and the net change in snowcap lower levels (SCLL) in meters from 1880–1980 along a section of the Rocky Mountains. A net negative change in the SCLL indicates a loss of rock or sediment, and a net positive change indicates a gain of sediment.

Table 1 shows the percentage of the year that a vertical section of the mountain range is exposed to snow melt erosion.



Figure 1

23.   According to Figure 1, at 13 km along the mountain range, the peak section is composed of:

A.  igneous rock and limestone.

B.  igneous rock and sandstone.

C.  limestone and sandstone.

D.  limestone only.

24.   At a peak section height of 20 meters, the net change in SCLL is mostly:

F.  greater than 20.

G.  between –10 and –30.

H.  less than –50.

 J.  between –40 and –50.

25.   Based on the information in Table 1, a peak section with a height between 40–45 meters would be exposed to snow melt erosion at approximately what percentage of the year?

A.  28%

B.  56%

C.  78%

D.  92%

26.   According to Figure 1, a net change in SCLL is most related to:

F.  exposure to rock and sediment.

G.  peak section composition.

H.  distance along the mountain range.

 J.  peak section height.

27.   According to the information in Table 1, which of the following figures best represents the relationship between the mountain’s height and the percentage of the year the mountain is exposed to snow melt erosion?






Microbial flora such as bacteria play an important role in maintaining the digestive tract of animals, where they are called gut flora. Bacteria exist in the stomach, duodenum, jejunum, ileum, and colon in different amounts and at different pH levels. Defecation output is a good indicator of digestive tract health. The higher the defecation output, the healthier the digestive tract. A student investigated the effects of creating a bacteria-free environment in a rat’s digestive tract.

Experiment 1

The student collected 10 rats to include in the experiment. Five of the rats were given antibiotics to kill all gut flora within their digestive tracts. The remaining 5 rats were not treated with antibiotics. All of the rats were allowed to eat a normal diet. The animals’ defecation amounts, measured in feces pellets, and pH levels of the defecation were measured after 5 hours. The results are shown in Table 1.


Experiment 2

Each of 5 different rats was given an antibiotic to kill all gut flora in the digestive tract. The rats were then given a dose of gut flora 1 hour later. The rats were allowed to eat a normal diet. Each rat’s defecation is measured in terms of pH level at 1 hour and again at 5 hours. The pH levels are compared in Table 2.


28.   Based on Experiment 1, what is the relationship between defecation output and pH level?

F.  As pH level increases, defecation output decreases.

G.  As pH level increases, defecation output increases.

H.  As defecation output increases, pH level decreases.

 J.  Both defecation output and pH levels remain the same.

29.   In which of the following ways are the designs of Experiments 1 and 2 different?

A.  A dose of gut flora was given to the rats in Experiment 2 and not in Experiment 1.

B.  A normal diet was followed in Experiment 2 and not in Experiment 1.

C.  A control group was established in Experiment 2 and not in Experiment 1.

D.  A smaller population was used in Experiment 1 than in Experiment 2.

30.   Which of the following hypotheses about the effects of a bacteria-free digestive tract in a rat is best supported by the results of Experiment 2? If the gut flora is eliminated and then reintroduced, the pH level will:

F.  remain the same.

G.  increase over time.

H.  decrease over time.

 J.  increase, and then decrease rapidly.

31.   Suppose that Rat 5 was given the gut flora 1 hour after being given the antibiotics. Based on the results in Experiment 2, one would predict that the pH level after 5 hours would be approximately:

A.  6.3

B.  6.7

C.  7.1

D.  8.0

32.   According to the passage, which of the following rats had the highest defecation output?

F.  Rat 3

G.  Rat 6

H.  Rat 8

 J.  Rat 10

33.   According to the results of both experiments, one can conclude that:

A.  antibiotics kill only microbes that are harmful to the digestive tract.

B.  pH levels in the digestive tract cannot be tested effectively.

C.  gut flora is necessary for the normal functioning of a healthy digestive tract.

D.  the presence of microbes in the digestive tract leads to unhealthy pH levels.


Students performed 3 studies to determine the effect that an object’s mass and wind resistance has on the rate that it travels to the ground from a height.

In each study, the students stood on top of a 20-foot bleacher inside the school gymnasium and used an adjustable fan to create wind resistance at a constant rate. The fan was either positioned on the floor, pointing upward, or on the 20-foot bleacher, pointing downward. The objects included a tennis ball, a golf ball, a feather, and a piece of paper.

Study 1

When no wind was blowing, the students dropped a tennis ball and a golf ball at the same time. The times it took for each object to hit the ground were recorded. The same process was followed for the tennis ball and feather, and the golf ball and piece of paper. The students performed the tests 3 times for each group of objects. The results are shown in Table 1.


Study 2

With the fan blowing upward, the experiment was repeated. The fan was turned off when the objects reached the ground. The results are shown in Table 2.


Study 3

With the fan blowing downward, the students performed the experiment in the same manner. The fan was turned off when the objects reached the ground. The results are recorded in Table 3.


34.   According to Study 3, which objects differed most in fall time?

F.  Trial 1, Tennis ball/golf ball

G.  Trial 2, Tennis ball/feather

H.  Trial 2, Golf ball/paper

 J.  Trial 3, Tennis ball/feather

35.   The fall time of the objects was different in Studies 2 and 3. This difference is most likely due to:

A.  wind direction.

B.  settle time.

C.  wind speed.

D.  drop height.

36.   Which of the following changes to all three studies would most likely have produced shorter fall times for all of the objects?

F.  Dropping the items from a height of 10 feet

G.  Increasing the speed of the fan

H.  Dropping the items at different times rather than all together

 J.  Measuring the times from an adjacent bleacher

37.   According to Study 2, which object consistently experienced the most wind resistance?

A.  Golf ball

B.  Paper

C.  Feather

D.  Tennis ball

38.   In Study 2 it took the paper longer than the feather to fall. Which of the following is the most likely explanation?

F.  The larger surface area of the paper causes greater wind resistance resulting in longer fall times.

G.  The heavier weight of the paper causes it to fall more quickly than the feather.

H.  The lighter weight of the feather causes it to fall more slowly than the paper.

 J.  The smaller surface area of the feather causes greater wind resistance, resulting in longer fall times.

39.   Based on the results of all three studies, which object generally had the longest fall time?

A.  Tennis ball

B.  Golf ball

C.  Feather

D.  Paper

40.   The students conducted a fourth experiment to test the rate at which each object falls in a partial vacuum. In the partial vacuum, there is no measurable resistance of any kind acting on the objects. What are the most likely results of this experiment?

F.  Each object falls much more slowly in a partial vacuum.

G.  Each object will fall at a nearly identical rate.

H.  The rate of fall will not be affected.

 J.  The objects will not fall in a partial vacuum.