ACT Past Papers with Answers

Paper 68

ACT January 2008

Form 61B · Science Test · 40 questions

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Paper 68 · ACT January 2008 · Form 61B · Science Test

2 mm) was the cofactor in all trials, and the temperature was varied from trial to trial (see Table 2). 2+ Enzymes calalyze (speed up) the rate of a biological reaction without being consumed in the reaction. Pyrococ- cus furiosu.f, an organism that lives in ocean thermal vents where temperatures remain near IOO°C, produLes the enzyme prolidase. Prolidase catalyzes the breakdown of proteins to release the amino acid proline. An enzyme's activiry is a measure of its effectiveness for a given reac- tion expressed as a percent of its maximum measured effectiveness. Table 2 Temperature Activity (°c) (%) 40 50 60 70 80 90 100 22 42 60 94 100 Experiment I Many enzymes function only in the presence of a metal ion, called a cofacfor. One ML of a standard solution containing prolidase and 0.4 mm (millimolar. a unit of concentration) cobalt ion (Co ') was mixed with I ML of a solution of Proteill X (of which proline is a component) at a pH of 7.0 and l OO°C. After 10 min. a substance that react.% with free proline to produce a bright red color was added to the solution. The solution was diluted to l 00 ML. and the intensity of the red color was measured and used to calculate the activity. The procedure was repeated for dif- 2+ Experiment 3 Experiment 2 was repeated, but from trial to trial, temperature was held constant at l OO°C, and pH was varied (see Table 3). ferent concentrations of Co and then for manganese ion (Mn ') and zinc ion (Zn ") at all of the concentrations (see Table l). Table 3 Table I Actlvity (%) pH Ion concentration Activity (%) (mm) 2+ 41 59 92 100 94 24 16 62 86 100 92 84 35 49 68 66 57 ACT-61B-SAMPLE GO ON TO THE NEXT PAGE. 40000000004 l. If, in Experiment 2, a trial had been done at 85°C. tbe activity would most likely have been:

Aless than 42%.Bbetween 42% and 60%.Cbetween 60% and 94%.Dgreater than 94%.

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Paper 68 · ACT January 2008 · Form 61B · Science Test

In a lab, the masses of 2 mineral samples. one of olivine and one of spinel, of the same size and shape were determined. Which of the following statements about the samples is most consistent with the inforrna- tion in Scientist 2's viewpoint? The mass of the olivine sample would be: spinel is more dense than olivine. spinel is more dense than olivine. olivine is more dense than spinel. olivine is more dense than spinel. ACT.6IB4AMPLE 43 GO ON TO THE NEXT PAGE. 40000000004 Passage V Experimeni 2 Carts having different masses were placed on a track in the presence of air. Siarting from rest at Point A, each cart was allowed to roll, as shown in Figure 2. The results are given in Table 2. (Note: At Points B and D, a cart's PE-O.) Potential energy (PE) is stored energy. Kinetic energy (KE) is energy of motion. An object's iotal mechanical energy is the sum of PE and KE. Objects in motion lose total mechanical energy because of fric¢ion. Students conducted 3 experiments to study mechani- cal energy. Experiment J In a vacuum chamber, a sphere on a string was released from various heights (h) and allowed to swing. For spheres of different masses, PE and KE (in joules, J) were determined at h and at the lowest point of the swing. as shown in Figure l. The results are given in Table l. Figure 2 Table 2 *- roof of chamber PEat Point A KEat Point B string Trial (J) (J) sphere *- floor of chamber Experiment 3 A toy consisted of a spring affixed to the inside of a box. The spring had much less mass than the box. When the toy was dropped and hit the floor, the spring com- pressed and then extended, throwing the toy upward. as shown in Figure 3. Figure I -box Table I 4- spring PEat lowest point KEat lowest point Mass PEath KEath (J) Trial (kg) (m) (J) (J) Figure 3 ACT-61&SAMPLE GO ON TO THE NEXT PAGE. 40000000004 The students tested 3 toys having the same mass but springs with different stiffnesses. The students dropped each toy through the air from 1.0 rn above the floor and observed the maximum height reached by the toy on its first bounce. The results are given in Table 3.

Agreater than the mass of the spinel sample becauseBless than the mass of the spinel sample becauseCgreater than the mass of the spinel sample becauseDless than the mass of the spinel sample because 19.6 29.4 19.6 19.6 29.4 19.6

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Paper 68 · ACT January 2008 · Form 61B · Science Test

The pattern depicted in Table 3 does not work for chromium, which has 24 electrons. Compared to vana- dium, which has 23 electrons, chromium has I less 4s electron and 2 more 3d electrons. Based on this information, which of the following notations best rep- resents the electron distribution in chromium? Is 2s 2p'3s 3p'3d 4s' ACT-61&8AMPLE 47 GO ON TO THE NEXT PAGE. 40000000004 Passage Vll Key hay Some soil bacteria can remove sulfate (SO -) from acid mine drainage {AMD, polluted water drainage from mining areas). The bacteria use the soil's organic carbon for energy and remove SO - by reducing it to sulfide (S -). Oxygen-poor conditions are required for the reduction process. Researchers studied other organic materials containing bacteria populations to see if those mixtures could also reduce SO4 in AMD. straw leaf compost straw and manure hay and manure Study I Four organic materials that contained bacteria popula- tions were selected for testing: straw, hay, leaf compost, and manure. The materials, either individually or in mix- tures of 2 of the materials. were packed to a depth of 50 cm in l O cm diameter glass columns (see Figure l ). Duplicates of each column were prepared. The moist and dry densities and the Larbon content (in kglm ) of each column's con- tents were measured. The results are shown in Table l. SO4 solution into column (in Study 2) 80 70 20 10 column contents 10 20 30 depth in column (cm) Figure 2 40 50 50cm Table 2 Figure I concentration (ppm) in column water on Day: Table I Column contents 50 100 150 Moist density (kg/m ) 100 75 500 286 412 Dry density (kglm,) 92 68 294 Carbon content Hay Straw Leaf compost Straw and manure Hay and manure 23 60 17 120 50 32 70 25 170 53 25 Column contents (kglm,) 41 31 94 64 92 48 15 Hay Stiaw Leaf compost Straw and manure Hay and manure Tables and Figure 2 adapted from Martin Rabenhorst, Bruce James. and Joey Shaw, "Evaluation of Potenlial Wetland Sub- strat6s for Optimizing Sulfate Reduction. 992 by the American Society for Surface Mining and Reclamation. 248 *Straw or hay was mixed with manure in a 1.2 ratio by dry weight. Stud) 2 An aqueous solution with a concentration of l 00 ppm SO4 (simulated AMD) and a pH of 6.5 was put through each column at a flow rate of 80 mL/day. On Day 50. the concentration in the water in each column was mea- sured at various depths. The results are shown in Figure 2. Table 2 shows the average S concentration in a column's water on Days 50, 100, and 150.

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AIs 2s 2p 3s 3p, 3d,BIs 2s 2p'3s 3p 3d 4sCIs 2s 2p 3s 3p 3d 4sDChoice J — see source image

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Paper 68 · ACT January 2008 · Form 61B · Science Test

Which of the following assumptions about AMD was most likely made by the researchers when designing Study 2 ? is a concentration that is much lower than that found in AMD. of that found in AMD. 10 END OF TEST 4 STOP! DO NOT RETURN TO ANY OTHER TEST. ACT.61B4AMPLE 49 English Mathematics Readling Science 1 C 36 F 1 A 31 B 1 C 1 C 2 H 37 B 2 H 32 F 2 G 2 F 3 A 38 G 3 B 33 C 3 B 3 A 4 J 39 A 4 G 34 G 4 H 4 H 5 A 40 H 5 D 35 E 5 A 5 A 6 H 41 B 6 H 36 G 6 G 6 F 7 D 42 H 7 B 37 A 7 D 7 D 8 G 43 C 8 J 38 F 8 F 8 F 9 B 44 F 9 D 39 C 9 D 9 D 10 F 45 D 10 H 40 J 10 F 10 H 11 B 46 J 11 A 41 C 11 C 11 C 12 H 47 A 12 H 42 H 12 F 12 H 13 B 48 H 13 E 43 A 13 D 13 B 14 J 49 D 14 F 44 J 14 F 14 J 15 B 50 F 15 E 45 B 15 A 15 C 16 H 51 D 16 H 46 H 16 G 16 F 17 B 52 J 17 E 47 D 17 B 17 C 18 F 53 B 18 G 48 F 18 J 18 J 19 C 54 J 19 E 49 E 19 D 19 A 20 F 55 D 20 G 50 J 20 H 20 F 21 A 56 F 21 D 51 E 21 D 21 B 22 H 57 C 22 G 52 K 22 H 22 J 23 B 58 G 23 A 53 E 23 A 23 B 24 F 59 D 24 F 54 G 24 J 24 G 25 B 60 H 25 D 55 E 25 A 25 D 26 H 61 B 26 J 56 H 26 G 26 F 27 D 62 J 27 D 57 E 27 A 27 B 28 J 63 A 28 G 58 J 28 H 28 H 29 C 64 J 29 E 59 D 29 B 29 D 30 J 65 B 30 G 60 F 30 H 30 G 31 B 66 J 31 A 31 C 32 H 67 D 32 J 32 G 33 A 68 F 33 B 33 D 34 J 69 D 34 H 34 G 35 B 70 H 35 A 35 D 71 A 36 H 36 G 72 H 37 B 37 D 73 D 38 G 38 H 74 F 39 A 39 A 75 C 40 J 40 J TABLE 1 fiocedures Used l Obtain Scale Scores from Raw Scores On each ol the lour tests on which you marked ACT Test 0861 B any responses, Ihe total number of correct responses yields a raw score. Use Ihe table below to convert your raw sccres lo scale scores. For each tesl. locate and circle your raw score or the range ol raw kores that indudes it in lh9 table below. Then, read acioss to elther outside column of Ihe table and circle the scale score that corresponds to that raw score. Aè you delermine your scale scores, enter Ihem in Ihe blanks provideij on th8 righl. The highest possibl. score for each lest is 36. The lowest possible scale score for any lest on which you marked any responses is 1. Next. compule the Compos'.e score by averaging the four scale scores. To do t..is. add your four scale scores and divide Ihe sum by 4. If the wtssulting number . nds in a fractior4, round it off to the nearest. nutTbber. (Round Jown any fraclion less Ihan one-h<lf" round up &,./ fraction that Is one-half or More.) Enter this nun.Ler in the blank. This is your ComFo¢ite score. Th J highest possible Composite score is 36. The lowest possible Composile score is 1 . Raw Scores Your Scale Score English Mathematics Reading Scienca Sum of scores Composlte score (sum + 4) NOTE.. If you left a iesl completely blank and maTked no items, do not list a scale score for that test. If any test was complet81y blank. do not calculate.a Com- poslte score. Test 1 Engllsh Test 2 Mathematlcs Test 3 R•adlng 3940 38 Te8t 4 SclerKe Scale Scorn Score JG 75 74 72-73 71 70 69 59 57-58 . 56 55 39 Ji 36 35 37 32 31 32 31 30 32-33 31 30 27 26 25 24 22-23 21 20 18-19 17 16 15 14 12-13 1e-11 51-52 49-50 28 27 26 25 24 23 62-63 44-415 4243 41>41 37-3y 30-31 29 27-28 5&S7 54-55 51-53 49-50 46-48- 43-45 41-42 33-40 J6-37 24 34-35 29-30 26-28 12-14 )-11

AAMD kills most 8011 bacteria on contact.BAMD contains high concentrations of SCOne hundred ppm SODOne hundred ppm SO4 is a concentration typical 28.29E&C 7 31.33 23.25 19.22 15.48

Form 61B · Science Test · 40 questions

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