ACT Past Papers with Answers

Paper 10 · ACT December 2022 · Form F07 · Science Test

Consider the claim “On average, the activity of results of Experiment 2 from pH 6.6 through pH 9.3 consistent with this claim? average TDT increased only. average TDT decreased only. average TDT initially increased and then decreased. average TDT initially decreased and then increased.

Paper 10 · ACT December 2022 · Form F07 · Science Test

In Experiments 1 and 2 combined, the incubation tem- perature was either at or below the freezing point of water for how many of the groups tested, if any?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Which, if either, of the paraffin and the cover slip likely functioned to slow the rate of evaporation from each slide?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Assume that for A.limax, the greater the activity level, the greater the frequency of cell division. Under the conditions of Experiment 1, an A.limax would most likely undergo the fewest cell divisions at which of the incubation temperatures tested?

Paper 10 · ACT December 2022 · Form F07 · Science Test

In Experiments 1 and 2 combined, for how many of Groups 1−10 was the average TDT less than 1 centimeter ?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Was the solution placed on the Group 10 slides acidic or basic? 39 GO ON TO THE NEXT PAGE. ACT-F07 4 4 Passage II The amino acid molecules necessary for life are thought to have been produced on Earth before organisms were present. Amino acids can be produced through chemi- cal reactions among ammonia (NH3), methane (CH4), hydrogen (H2), and water (H2O). Four hypotheses have been proposed to describe the conditions that were respon- sible for the production of amino acids on Earth. Hypothesis 1 Amino acids were introduced to Earth by meteors containing NH3, CH4, H2, and H2O. If the reactions among these 4 substances are provided enough energy, amino acids can be produced. As meteors containing these sub- stances entered Earth’s atmosphere, the substances were rapidly heated by friction, and this heat resulted in immedi- ate amino acid production on the surface of the meteors. Hypothesis 2 Hypothesis 1 is correct that meteors brought NH3, CH4, H2, and H2O to Earth; however, amino acid produc- tion did not occur on the meteors. Once a meteor contain- ing these substances entered Earth’s atmosphere, the substances were released into the atmosphere. Meteors continued to enter the atmosphere over hundreds of mil- lions of years. The concentration of these substances in the atmosphere eventually became high enough for the reac- tions that produce amino acids to occur. The energy pro- vided to these reactions was UV light energy from the sun. Hypothesis 3 Meteors had nothing to do with the production of amino acids. Thermalvents (cracks in the floors of Earth’s oceans) allowed magma from Earth’s crust to seep into the ocean. The magma caused some of the ocean water to boil. Since ocean water contains dissolved NH3, CH4, and H2, these substances were released into the atmosphere (along with H2O) upon boiling. Then, UV light from the sun pro- vided the energy for these substances to react to produce amino acids. Hypothesis 4 Magma from thermal vents did not provide enough energy to cause ocean water to boil; however, the magma did provide enough energy to cause the NH3, CH4, and H2 dissolved in ocean water to react with the ocean water, pro- ducing amino acids. These reactions occurred near the ther- mal vents.

Paper 10 · ACT December 2022 · Form F07 · Science Test

Suppose that a scientist determined that UV light does not provide enough energy to cause any chemical reac- tions to occur. This finding would weaken which hypotheses?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Hypothesis 3 and Hypothesis 4 agree on which of the aspects of amino acid production listed below? I. The source of the substances needed for amino acid production II. The location of amino acid production III. The source of the energy needed for amino acid production

Paper 10 · ACT December 2022 · Form F07 · Science Test

Which of Hypotheses 1 and 2, if either, state(s) or sug- gest(s) that amino acid production occurred on the sur- face of a meteor?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Which hypothesis suggests that the reactions among the 4 substances that form amino acids occurred in an aqueous solution?

Paper 10 · ACT December 2022 · Form F07 · Science Test

The chemical formula for the amino acid glycine is C2H5O2N. Based on the information in the passage, how many molecules of methane would be needed to provide the correct number of carbon atoms in 1 mole- cule of glycine? 40 GO ON TO THE NEXT PAGE. ACT-F07 4 4

Paper 10 · ACT December 2022 · Form F07 · Science Test

The diagram below best illustrates which hypothesis?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Which hypotheses, if any, claim that amino acid pro- duction occurred within thermal vents? ocean magma thermal vent released substances sun UV light 41 GO ON TO THE NEXT PAGE. ACT-F07 4 4 Passage III A class of physics students performed 3 experiments on the topic of motion using the apparatus shown in Figure 1. Figure 1 In each trial, the following occurred: First, the stu- dents placed a platform with a ramp at a height Δy above a sandbox. Then, they released either a 10 g solid sphere or a 10 g hollow sphere from a height h above the platform. The sphere rolled down the ramp and through a photogate (a device that emitted 2 beams of light, spaced 1.5 cm apart, and calculated the speed, v, of a sphere passing through both beams). Next, the students started a timer when the sphere rolled off the platform, and they stopped the timer when the sphere landed in the sandbox. They recorded this time interval as the sphere’s timeofflight, Δt. Last, they measured the horizontal distance traveled by the sphere while it was in flight, Δx. Experiment 1 In Trials 1−5, the students set Δy to 95 cm and released the solid sphere from various h (measured in cm). They recorded v in centimeters per second (cm/sec), Δt in sec, and Δx in cm (see Table 1). Experiment 2 In Trials 6−10, the students set Δy to 95 cm and released the hollow sphere from various h (see Table 2). Experiment 3 In Trials 11−15, the students set Δy to various values and released the solid sphere from h = 25 cm (see Table 3).

Paper 10 · ACT December 2022 · Form F07 · Science Test

Based on the results of Experiment 1, as h increased, did v decrease or increase? ramp, the slower the sphere will be moving at the bottom of the ramp. ramp, the faster the sphere will be moving at the bottom of the ramp. ramp, the slower the sphere will be moving at the bottom of the ramp. ramp, the faster the sphere will be moving at the bottom of the ramp. Table 2 Trial h (cm) v (cm/sec) Δt (sec) Δx (cm) 06 05 077 0.44 034 07 15 133 0.44 059 08 25 171 0.44 076 09 35 203 0.44 089 10 45 230 0.44 101 Table 3 Trial Δy (cm) v (cm/sec) Δt (sec) Δx (cm) 11 095 187 0.44 082 12 145 187 0.54 102 13 195 187 0.63 118 14 245 187 0.71 132 15 295 187 0.78 145 Δx h sandbox sphere platform photogate Δy Note: The figure is not drawn to scale. Table 1 Trial h (cm) v (cm/sec) Δt (sec) Δx (cm) 1 05 084 0.44 037 2 15 145 0.44 064 3 25 187 0.44 082 4 35 221 0.44 098 5 45 251 0.44 111 42 GO ON TO THE NEXT PAGE. ACT-F07 4 4

Paper 10 · ACT December 2022 · Form F07 · Science Test

Based on Figure 1, in any trial, Δy was: sphere. ramp and the top of the sandbox. form and the top of the sandbox.

Paper 10 · ACT December 2022 · Form F07 · Science Test

A controlledvariable is a variable that is held at a con- stant value throughout an experiment. In which of the experiments, if any, was Δy a controlled variable?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Based on the results of Experiment 2, which of the fol- lowing values of v and Δx, respectively, would most likely have been measured for the hollow sphere if it had been released from h = 10 cm ? v (cm/sec) Δx (cm)

Paper 10 · ACT December 2022 · Form F07 · Science Test

Consider a landingpoint to be a point in the sandbox where a sphere landed. Based on the values of Δx in Trials 1−15, at the conclusion of the experiments, what was the greatest distance between 2 landing points in the sandbox? (Note: The sandbox was not moved throughout the experiments.)

Paper 10 · ACT December 2022 · Form F07 · Science Test

Consider the value of v for the hollow sphere in Trial 9. An object moving in a straight horizontal line with this speed would travel approximately what dis- tance during a 2 sec period?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Suppose that in Trial 13 the speed v had been 171 cm/sec. Based on the results of Experiments 2 and 3, which of the following errors could have accounted for this result? of the solid sphere. the hollow sphere. instead of 25 cm. instead of 195 cm. 43 GO ON TO THE NEXT PAGE. ACT-F07 4 4 Passage IV The soil beneath a heavy structure can fail (crack or flow). Adding wires to a soil produces a mixture with a greater compressivestrength than that of the soil alone. (Compressive strength is the minimum downward pressure that will cause a material to fail.) Mixtures of Soil X and 1 mm diameter steel wires were tested for compressive strength. All the wires in a mixture had the same length (1 cm, 2 cm, or 3 cm) and the same angle (90°, 120°, 150°, or 180°, as shown below). Figures 1, 2, and 3 show how the compressive strength of the mixtures with 1 cm, 2 cm, and 3 cm wires, respec- tively, varied with wire angle and with the percent by mass of the wires. Figure 1 Figure 2 Figure 3 Diagram and figures adapted from Amir Kalhor, “Effect of Metal Fibers on Clayey Soils.” ©2008 by Electronic Journal of Geotechni- cal Engineering. 120 130 160 170 140 150 wire angle (°) 120 150 180 compressive strength (kPa) 90

Paper 10 · ACT December 2022 · Form F07 · Science Test

In Figures 1−3, consider the compressive strengths of the mixtures containing 0.75 percent by mass of wires. For which of the wire lengths was the compressive strength greater for a wire angle of 120° than it was for a wire angle of 90° ?

Paper 10 · ACT December 2022 · Form F07 · Science Test

According to Figures 1−3, for mixtures containing

Paper 10 · ACT December 2022 · Form F07 · Science Test

According to Figures 1−3, the greatest compressive strength was recorded for the mixture with which wire length, wire angle, and percent by mass of wires? length angle percent by mass

Paper 10 · ACT December 2022 · Form F07 · Science Test

In Figure 1, consider the compressive strength of the mixture containing 0.75 percent by mass of 1 cm wires with an angle of 180°. Would a downward pressure of 160 kPa cause this mixture to fail? sive strength of the mixture. pressive strength of the mixture. sive strength of the mixture. pressive strength of the mixture.

Paper 10 · ACT December 2022 · Form F07 · Science Test

According to Figure 3, increasing the percent by mass of 3 cm wires resulted in the least variation in com- pressive strength for which wire angle?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Based on the information provided, the compressive strength of Soil X alone was most likely: 45 GO ON TO THE NEXT PAGE. ACT-F07 4 4 Passage V Ultraviolet (UV) light is harmful to skin. A sunscreen applied to the skin lessens the skin’s exposure to the harm- ful light, such as through absorption of the light. A sun- screen’s sunprotectionfactor (SPF) is a measure of its ability to lessen exposure. Students did 2 experiments to measure the absorbance of UV light by various solutions at 25°C, each solution containing a single sunscreen. To make their measure- ments, the students used a spectrophotometer (see diagram). diagram of spectrophotometer In each trial of the experiments, Steps 1−4 were performed:

Paper 10 · ACT December 2022 · Form F07 · Science Test

According to the results of Experiment 1, the maxi- mum absorbance by each of the sunscreen solutions was obtained at a wavelength closest to which of the following?

Paper 10 · ACT December 2022 · Form F07 · Science Test

In Experiment 2, at a given sunscreen concentration, as SPF increased, the maximum absorbance:

Paper 10 · ACT December 2022 · Form F07 · Science Test

In Experiment 1, which type of UV light was more effectively absorbed by each sunscreen solution? 320 nm was greater than the absorbance of light between 320 nm and 400 nm. 400 nm was greater than the absorbance of light between 290 nm and 320 nm. 320 nm was greater than the absorbance of light between 320 nm and 400 nm. 400 nm was greater than the absorbance of light between 290 nm and 320 nm.

Paper 10 · ACT December 2022 · Form F07 · Science Test

Which of the following conditions differed between Experiments 1 and 2 ?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Suppose that a sunscreen with an SPF of 20 had been tested in Experiment 1. The maximum absorbance by the solution of this sunscreen would most likely have been closest to which of the following?

Paper 10 · ACT December 2022 · Form F07 · Science Test

PABA is a common sunscreen ingredient that has its maximum absorbance in the UVB light range. Which of the following wavelengths is a possible wavelength at which PABA has its maximum absorbance?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Assume that in Step 4, absorbance measurements were made in 5 nm increments. Based on this information, each sunscreen solution was exposed to how many dif- ferent wavelengths of UV light? 47 GO ON TO THE NEXT PAGE. ACT-F07 4 4 4 4 Passage VI In the human body, O2 and CO2 are exchanged between the lungs and the blood and between the blood and the tissues as indicated in Figure 1. These exchanges occur by the diffusion of each gas from a region where its partial pressure (the pressure contributed by a single gas) is higher to a region where its partial pressure is lower. The figure gives the partial pressures PO2 and PCO2 in the lung alveoli (sacs), in the tissue cells, and in the blood of a healthy rest- ing person at sea level. 48 GO ON TO THE NEXT PAGE. ACT-F07 Figure 1 lung capillaries right side of heart left side of heart tissue capillaries atmosphere: PO2 = 152 mm Hg PCO2 = 000.3 mm Hg lung alveoli: PO2C = 104 mm Hg PCO2 = 040 mm Hg PO2C = 40 mm Hg PCO2 = 46 mm Hg PO2C = 100 mm Hg PCO2 = 040 mm Hg PO2C = 100 mm Hg PCO2 = 040 mm Hg PO2C = 40 mm Hg PCO2 = 46 mm Hg tissue cells: PO2C ≤ 40 mm Hg PCO2 ≥ 46 mm Hg Note: Dashed arrows indicate exchange of O2 and CO2. Solid arrows indicate direction of blood flow. Partial pressures are given in millimeters of mercury (mm Hg). 49 ACT-F07 4 4 Figure 2 shows how alveolar PO2 and PCO2 vary with alveolarventilation (volume of air per unit time available to the alveoli for gas exchange). Figure 2 Figures adapted from Arthur J. Vander, James H. Sherman, and Dorothy S. Luciano, Human Physiology: The Mechanisms of Body Function. ©1985 by McGraw-Hill, Inc.

Paper 10 · ACT December 2022 · Form F07 · Science Test

According to Figure 1, for a healthy resting person at sea level, as blood passes through the left side of the heart, which is greater, the PO2 or the PCO2 ? ; its value is 100 mm Hg through the left side of the heart. ; its value is 40 mm Hg through the left side of the heart. ; its value is 100 mm Hg through the left side of the heart. ; its value is 46 mm Hg through the left side of the heart.

Paper 10 · ACT December 2022 · Form F07 · Science Test

The PCO2 in the lung capillaries that enter the lung alve- oli differs from the PCO2 in the lung capillaries that leave the lung alveoli. Based on Figure 1, for a healthy resting person at sea level, what is the range of the PCO2 in the lung capillaries?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Based on Figure 2, if a person’s alveolar ventilation decreases from a value of 6.3 L/min, how do the person’s alveolar PO2 and alveolar PCO2 , respectively, change? alveolar PO2 alveolar PCO2

Paper 10 · ACT December 2022 · Form F07 · Science Test

Based on Figure 1, for a healthy resting person at sea level, does O2 in the air that enters the lung alveoli dif- fuse into the lung capillaries? in the lung alveoli is greater than the PO2 in the lung capillaries. in the lung capillaries is greater than the PO2 in the lung alveoli. in the lung alveoli is greater than the PO2 in the lung capillaries. in the lung capillaries is greater than the PO2 in the lung alveoli.

Paper 10 · ACT December 2022 · Form F07 · Science Test

Consider the values of PO2 and PCO2 that are given in Figure 1 for the lung alveoli. According to Figure 2, to maintain those values, alveolar ventilation must be closest to which of the following?

Paper 10 · ACT December 2022 · Form F07 · Science Test

Consider the combinations of PCO2 values for tissue cells and tissue capillaries listed in the table below. For how many of the combinations would CO2 diffuse from the tissue cells into the tissue capillaries? PCO2 in tissue cells PCO2 in tissue capillaries 52 mm Hg 50 mm Hg 52 mm Hg 60 mm Hg 46 mm Hg 50 mm Hg 46 mm Hg 60 mm Hg 0 alveolar ventilation (L/min)