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OFFICIAL ACT Form F07 · 12 2022

Science

30 questions ~9 min recommended
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=== Experiment 2 ===
Two experiments examined how pH and temperature affect the activity of Amoeba limax (a single-celled eukaryote).

Twenty more of the slides were equally divided into 5 groups (Groups 6−10). Each slide was prepared as in Experiment 1, except that for each group, the aqueous solution had a different pH (see Table 2).

Each of the Group 6 slides was incubated at a temperature of 10°C. During incubation, the movement of the A. limax on each slide was observed for 30 min, and the TDT by the A. limax over the 30 min was recorded. The average TDT for Group 6 was then determined. The procedure for Group 6 was repeated for each of Groups 7−10.

The results are shown in Table 2.

Table 2 adapted from C. F. A. Pantin, “On the Physiology of Amoeboid Movement III.—The Action of Calcium.” ©1926 by The Company of Biologists Ltd. The procedure for Group 1 was repeated for each of Groups 2−5, except that each group was kept at a different incubation temperature.

The results are shown in Table 1.

Table 1 adapted from C. F. A. Pantin, “On the Physiology of Amoeboid Movement II.—The Effect of Temperature.” ©1924 by The Company of Biologists Ltd.

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1. According to the results of Experiment 1, as the incubation temperature increased, the average TDT:

2. Consider the claim “On average, the activity of A.limax always increases with increasing pH.” Are the results of Experiment 2 from pH 6.6 through pH 9.3 consistent with this claim?

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

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

5. 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?

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

7. Was the solution placed on the Group 10 slides acidic or basic?

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

9. Which of the hypotheses suggest(s) that the reactions among the 4 substances that form amino acids occurred in an aqueous solution?

10. Which hypotheses, if any, claim that amino acid production occurred within thermal vents?

11. 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 of glycine?

12. Consider a landing point to be a point in the sandbox where a sphere landed. Based on the values of Δx in Trials 1−15, what was the greatest distance between 2 landing points in the sandbox?

13. Based on the results of Experiment 2, which of the following 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?

14. Was the solution placed on the Group 10 slides acidic or basic?

15. 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?

16. According to Figures 1−3, for mixtures containing 1.0 percent by mass of wires bent at an angle of 90°, as wire length increased, the compressive strength:

17. 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?

18. According to Figure 3, increasing the percent by mass of 3 cm wires resulted in the least variation in compressive strength for which wire angle?

19. Based on the information provided, the compressive strength of Soil X alone was most likely:

20. According to the results of Experiment 1, the maximum absorbance by each of the sunscreen solutions was obtained at a wavelength closest to which of the following?

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

22. In Experiment 1, which type of UV light was more effectively absorbed by each sunscreen solution?

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

24. 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?

25. 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?

26. 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 different wavelengths of UV light?

27. 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 P and alveolar P , respectively, change?

28. Based on Figure 1, for a healthy resting person at sea level, does O in the air that enters the lung alveoli diffuse into the lung capillaries?

29. Consider the values of P and P 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?

30. Consider the combinations of P CO values for tissue cells and tissue capillaries. For how many of the combinations would CO diffuse from the tissue cells into the tissue capillaries?

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