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Practice Test 11 - ACT Science

20 questions. Answer them in any order, then submit to see your score and every explanation.

  1. A student measured the speed of a cyclist at different times during a ride. Figure 1 shows speed versus time. During which interval did the cyclist's speed decrease?
  2. In a lab study, the effect of exercise on memory retention was tested. Participants performed different exercise routines, and their ability to recall information was assessed. The difficulty of the information and the study time were kept constant. Which factor is the dependent variable?
  3. Four instruments are used to measure the same time interval. Which measurement shows the greatest precision (smallest increment implied by the recorded value)?
  4. Based on Table 1, each increase of 1.0 in magnitude corresponds to an increase in energy released of approximately what factor?
  5. Which result would be inconsistent with Scientist 1's proposal?
  6. In an experiment, researchers wanted to determine the effect of sunlight on plant growth. They placed 20 plants in a greenhouse, with 10 plants receiving 6 hours of sunlight per day and the other 10 receiving no sunlight. At the end of four weeks, they measured the height of each plant. What is the independent variable in this experiment?
  7. Based on Figure 1, which bin serves as the control group?
  8. Which of the following best explains the readings in Figure 1?
  9. Biologists observed bacterial population growth in a nutrient broth over several hours. Figure 1 shows population size versus time. If the trend from 4 to 8 hours continues to 10 hours, what population size would be the best estimate at 10 hours? Points are (0, 1), (2, 2), (4, 4), (6, 8), and (8, 16), connected by straight segments. Caption: The population approximately doubles every 2 hours over the interval shown; extrapolation beyond 8 hours assumes the same doubling pattern continues.
  10. A field study assessed whether a pesticide (PX) reduces aphid counts on soybean plants. Two adjacent plots were used: Plot 1 was sprayed with PX; Plot 2 was not sprayed. Aphids per plant were counted weekly for 4 weeks. During Week 3, a heavy rainstorm occurred that washed insects from leaves. The authors concluded: "PX caused the decline in aphid numbers." Which statement best evaluates the validity of the author's conclusion?
  11. A student compared the average time it took 4 runners to complete a 5 km race. Figure 1 shows the times. According to Figure 1, which runner was fastest?
  12. A biologist traces airflow through a simplified human respiratory system diagram (Figure 1). Arrows indicate the direction of airflow during inhalation. Based on Figure 1, air flows from the trachea directly into the:
  13. Scientist 1 claims that the main benefit of a vegetarian diet is reducing heart disease risk. Scientist 2 argues it's more about environmental sustainability. Both scientists would agree that:
  14. According to Figure 1, at which wavelength do the two paints reflect the same percentage of light?
  15. At which step in Figure 1 is the independent variable set?
  16. To measure the concentration of a dye, an experimenter made a calibration curve with a spectrophotometer. Steps: (1) Prepare standards of 0.00, 0.20, 0.40, 0.60, 0.80 mM dye in identical cuvettes. (2) Wipe cuvette sides with a tissue and insert into the instrument in the same orientation. (3) Zero the spectrophotometer using a blank cuvette containing water. (4) Measure absorbance of each standard and plot absorbance vs. concentration. The blank cuvette accidentally contained a very dilute dye solution (not pure water). Expected pattern: absorbance increases linearly with concentration. If the blank contained dye, the measured absorbances of standards would most likely:
  17. Based on Figure 1, the difference between the activity of Enzyme A and the activity of Enzyme B is greatest at which pH?
  18. Scientist 1 suggests that the primary reason for animal migration is seasonal food availability. Scientist 2 argues it's for breeding purposes. Which statement is consistent with Scientist 2's viewpoint but not Scientist 1's?
  19. Researchers tested the effect of sunlight on plant growth by placing 20 plants under direct sunlight and 20 plants in shaded areas for 4 weeks. Height was measured weekly. Which of the following is the best criticism of this experiment?
  20. Scientist 1 hypothesizes that the main driver of species extinction is habitat destruction. Scientist 2 suggests climate change is more significant. Both scientists would agree that:

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