ACT Past Papers with Answers

Paper 24 · ACT April 2019 · Form Z15 · Science Test

342 For a given road type, as vehicle mass increased, the (Iverage S: increased only. varied, but with no general trend.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Based on Table l and Fioure I, the color of the sample at 30°C w(IS'. red. O'ohobo o 100.0 £> ¥D 50.0 y 0.0

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Based on Figure I, as the sample was heated from O°C to IOO'C. the mass of the saJnple decreased by approximately". o&oNO 0 80.0

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Bat>ed on Figure I, the change that occurred in the .8ample as it was heated from 175°C to 300°C would be best Teprcsented by which of the tollowing chemical equation%. CuSO,.3H,O 4 CuSO,.H,O + 2H,O

Paper 24 · ACT April 2019 · Form Z15 · Science Test

A student claimed that 50 g of CuSO4 will dissolve in 300 g of H O di 20°C. Does Table 2 support this 0sobO> ICT-215 39 GO ON TO THE NEXT PAGE. 000000000 Passage 11 During a dcmonstr&tion, a teacher placed 20 ML of water l O ML of isoprop)l alc'ohol {IPA), dnd I drop of blue food coloring into a test tube, capped the te8t lube, and inverted it 6 times. Next. she addcd 7 g of ammonium sulfate (AS), an ioniL solid, to the tesl tube, capped the test tube, and vigorously shook it for 10 sec. Then, over the 15 sec period immediately following the sh&king, the mix- turt in the test lube completely scparated into 2 distinct liquid layers (see figure). Student 3 Over the 15 sec, the mixture separated into 2 laycrs because the AS dissolved in the IPA only. causing the den- gity of the IPA layer to increase. The watcr layer was on top, and the IPA layer was on the bottom. The AS disqolved in the IPA only becausc AS breaks apart into ions when dissolved in IPA. Blue food coloring is p()lar, so it dis- solved in the water only. st￿dent 4 Over the 15 sec. the mixture separated into 2 layers because the AS dissolved in the ￿'￿ter only, causing the density of the wateT layer 10 increasc. The IPA layer was on top, and the water layer was on the bottom. The AS dis- solved in the water only, because AS breaks apart into ions when dissolved in wateT. Blue food coloring is polar: so it dissolved in the IPA only. 5sec 15 sec Note: The darker liquid was blue, and the lighter liquid was colorless.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Which of Students l and 2. IF either, claimed that water is denser than IPA ?

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Suppose that 20 ML of water and 20 ML of IPA are poured into a beaker, mixed, and then allowed ro settle. Based on Student 2's explanation, the resulting con- tentg of the beaker would best be represented by which of the following diagrams? FiguTe adapted from Eric C. Person, Donnie R. Gold8n, and Brenda R, Royce, "Salting Elfects as an IllustTalion of the Relalive Strength of Intermolecular Forces.. k02010 by Division ol Ch9mical Educalion, Inc., AmeriGan Chemical Sociaty- The teacher &sked each of 4 students to provide an expliin&tion for what occuired in the test tube over the 15 sec period. Srudeni I Over the 15 sec: the mixture scparated into 2 layers because IPA is denser than watcr. The water layer was on top, and Lhe IPA layer Wcl8 on the bottom. The AS dissolved in the IPA only: because AS breaks apart into neutral mole- cules when dissolyed in IPA. Blue food coloring is polar, so it dibsolved in the watei only. water IPA dissolved in water IPA srudent 2 Over the 15 sec, the mixture separated into 2 layer% because water is denser than IPA. The IPA layer was on top, and the water layer was on the bottom. The AS dis- solved in the water only, because AS breaks apart into neu- tral molecules whcn dissolved in wateT. Blue food coloring is polar, so it dissolved in the IPA only. water IPA IPA watei water 40 GO ON TO THE NEXT PAGE. ACT-Z15 40000000004

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Consider the diagram below. I l. Based on the figure, 5 scc aftcr the shaking, would the contents of the test tube have been better classified as a heterogeneous mixture or a homogeneous mixture. tube varied in composition from one region to another. tube were unitorm in composition throughout. tube varied in composition from one region to another. lube were uniform in compo%ition throughout.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Which student5, if any. would be likely to agree that after the 2 layers completely separated, the blue tood Loloring and the AS were boih dis8olved in the same layer?

Paper 24 · ACT April 2019 · Form Z15 · Science Test

C 51. A 11. B 51. B 11. A 11. A

Paper 24 · ACT April 2019 · Form Z15 · Science Test

The qiatement 'When AS dissolves in a liquid. the density of the resulting solution 18 greater than the den- sity of the liquid alone" is consistent with The explana- tion(s) given by which of Students 3 aT]d 4, if either? IPA + dissolved blue food coloring water + dissolved AS The locations of the water, IPA, dissolved blue food coloring, and dissolved AS shown in the diagram are consistent with the explanation(s) given by which of the students,.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

The chemical formula of AS is (NH4)2SO . Based on Student 3's explanation, which of the following chemi- cal equations best represellts a process tha[ only occurred in the IPA ? ACT.Z15 41 GO ON TO THE NEXT PAGE. 4Joooocooo4 Passage 111 A consumer safely laboratory conducted 3 studies of vehicle braking perfortnance under various conditions. Stud) 2 Three hundred kilograms ot Largo was placed into each of the vehicles that were te%ted in Study I, and the procedures ot Study I were repeated. Table ? Shows the results. Table 2 Road type Average S (m) Average B (mlsec~) System dry wet Str4dy I Each of 3 ideThti¢al vehicles was equipped wilh a dif- ferent braking system (System X, System Y, or System Z). Each vehicle was subjected to 10 trials on a dry road and 10 trials on a wet road. In each trial. the tollowing sieps were performed.. l. The vehicle was acceleraled to 30 mlsec.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Which of the following statements about the design of the 3 studies is consistenr w'ith their descriptions. -3 vehicles weie involved. involved. I'ehiclcs v'ere teslcd on both road types. Studies 2 and .3 were the only 2 studies in which System Z was not tested.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Any braking system that resulted in an average S that was gJreater than 50.0 m was designated (Is "unsafe" by Ihe researchers ai the lab()ratory. Based on the results of Studies l and 2, which system(s} was(were) most likely desitrnated as 'unsafe" ullder at least I set of conditions?

Paper 24 · ACT April 2019 · Form Z15 · Science Test

The table below give% the rnasses of the vehicles tested in Study 3. Vehicle Mass (kg) Compact Sedan Minivan Truck

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Consider the set of l O trials in Study 2 in which the vehicle equipped with System Y was tested on the dry road. Which of the following statements about thc vehicle's 10 stopping disiances is most likely correct? some of the distances were greater than 60.7 m. IfA) mlsec), 2xS The average B for thls set of trials was J 0.0 m/seL Was the average S more likely less than 45.1 tn or greater than 45.1 m ? lower %peed requiTes less digtance 10 come lo a stop, a higher speed requires lesb distance to come to a stop. from a lower speed requires more distance to come to a sLop, from a higher speed require.g more di%tance 10 come to a stop, ACT-ZI 5 43 GO ON TO THE NEXT PAGE. 4000000000 Passage IV Scientist5 Studied the speed of the wind and Ihe size of sand grains at 4 sites on a sand dune {see diagra￿). At each site, 4 anemomgters (devices foi measuring wind speed) were atiached to a vertical pole at dilferent heights above the ground, and a sand trap was placed at the base of Ihe pole: Each trap could collect only windblown sand grains having dianieters from 0.0625 mrn to 0.5 tnm. The mass of the sand collected at eiich site was mea- sured. Then the sand from each site wa8 silted through a staLk of 12 screens to separate the grains into 13 portions according to diameter. (Each SLreen had uniform opening of a s￿aller diameter than the opellings in the screen above.) The perccnt of the %and's mass from grains making up each of ihe 13 Portions was determined (see Figure ?). dune crest lee slo 30 30 anemometer wind direction 20 20 dune crest slope intcrdune base trap 1 3 5 7 9 11 13 Portion 1 3 5 7 9 1113 Portion interdulle stoss base 30 Note: Diagram is not to sca]e. diagratn of siles 20 20 Stud) Over a particular 45 min period, wind speed was mea- suied muliiple times by each anemometer and sand was collected at all 4 sites. 1 3 5 7 9 11 13 Portion Note: The afverage diameter of the sand grain8 in a portion decre&ses to the right along the ,r-axis. 1 3 5 7 9 1113 Portion The average wind speed at each anemomeier for the 45 tnin period was calculated. Then each average wind spced was converted to a relative w'ind speed. (The relative wind speed at an anemometer equaled the average wind speed at the anemomeier dividcd by the avcragc wind speed 12.0 m above the ground at the dune crest site for the same period.) The results aTe shown in Figure l. Figure 2 Flgures adapted from lan Walker, "Secondary Airflow and Sedi- ment Transport in the Lee of a Reversing DuHe. @1999 by John Wiley and Sons, Ltd. dune crest slo inteidune base Figure I 44 GO ON TO THE NEXT PAGE. ACT-Z15 000000000

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Suppose that in S(udy 3, a fifth vehicle had been tested on the dry road, and its average B was determined to be 7.7 m/sec-, Based on the result5 of Study I, the average S for this vehicle on the dry road would most likely have been closest to the average S in Study 3 for which other type of N'ehicle on the dry Toad'l Truck

Paper 24 · ACT April 2019 · Form Z15 · Science Test

According to the results of Studies l and 2: colnpared with the trials performed on the dry road, the trials per- formed on the wet road resulted in: average braking decelerations. age braking decelerations. age braking decelerations. age braking decclcrations.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

In a new set of l O trials pcrformed on the dry road, the vehicle with Sygtem Z was accelerated to 60 rnlsec with cargo. To calculate B, the following equation was used., 1,732 3,039

Paper 24 · ACT April 2019 · Form Z15 · Science Test

According to Figure I, at the interdune site, as aneTnomeier height above the ground increased, rela- tive wind speed,, increased only. increased, thell decreased.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

According to Figur¢ 2, sand grains making up which 2 adjacent portions accounted for more than half of the total Inass of the collected sand from the dune crest site? Portions 8 and 9

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Ir in the study an anemometer hdd been attached to the pole at the dune crest site at a height of 4.1 m above thc ground, the relatiTr'e wind speed at that anemometcr would most likely have been closest to which of the following.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

What was the average wind speed 12.0 m above the ground at the dune crest site for the 45 min period? Acf.z1S 45 GO ON TO THE NEXT PAGE. 40000000004 Passage V Key As a person ages, Ihe levels of anliuxidunts-com- pounds that reduce the number of cell-damaging reactive oxvgen molecules (ROM)-may decrease in the body. Te¢i extracts are a dietary source of anlioxidants. Table I shows the percent by mass of each of the iajor antioxidants (Al-A4) present in 5 tea extracts 1,100 1,0 (Tl-T5). 81KI 700 600 500 400 % 300 Table I Antioxidant (perccnt by mass) Al A2 A3 A4 Tea extTact Tl T2 T3 T4 T5 14 initial anlioxidant concentration Cmg/L) 10 21 12 Figure I Researchers studied the ability of Al-A4 and of TI-T5 to reduce the number of ROM. Figure 1 adapted from T. Nakagawa and T. Yokozawa, "Direcl Scavenglng of Nilric Oxide and Superoxide by Green Tea., <92002 by E Isevier Inc. Stiid}' 2 Elderly male rats received the same daily dose of T I , T2, T3. T4, or T5. or water only, for 4 weeks. A I mg Sdmple of he&rt tissue was then collected from each rat. Each sample was placed in a 3eparatc tcst tube con- taining 10 ML of a solution of the compound TBA. Each tube was incubated at IOO°C for I hr to allow the TBA to react with all the malondialdehi'.de (a produLt of ROM cell damage) in the sa￿PIe to form a pink dye. The concentra- tion of pink dyc was mcasurcd to determine the malondi- aldehydc concentration and, thus, the extent of ROM cell damage in the sample. Solutions having the same concentration of ROM and various concentrations of Al, A2, A3, or A4 were ineu- baled, each in a separate test tube at 25°C for 30 tnin. The compound NBT was then added to each tube. where it reacted with all the remaining ROM to form the blue dye formazan. Figure I shows, for AL-A4, how the foT- mazan concelltration varied with the initial antioxidant concentration. ACT-Z15 46 GO ON TO THE NEXT PAGE. 40000000004 Figure 2 shows the average malondialdehyde concen- Iraiion of the ,£olutions resulting from each treatmenL. 650 600 550 500 450 E 4(Xl 350

Paper 24 · ACT April 2019 · Form Z15 · Science Test

The best-sorted sand in the study was the sand made up of grains having the .¥mallest rangc of diameters. Based on Figure 2, the collected sand from which Site was the best sorted?

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Suppose thal the coIlected sand from the stoss biise site had a IOLal mass of 200 g. Ba.sed on Figure 2, the salld grains making up Portion 9 would have had a mass closest to which of the following.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

The medium sand grains collected in the study were those that made up Portions 14, and the I'eryfine sand grains collected in the study were those that made up Portions l 0-13. According to Figure 2. from site to site downwind, how did the total percent by mass of the medium sand grains change. and how did ihe total perceni by ma%,s of the very fine sand grains change? medium gand grain very fine sand grains decreased increased increased decreased increased increased decreased decreascd

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Based on the results of Study I, at an initRal antioxi- dant concentration of 5.0 mglL, the solution containing which alltioxidant had the lokvest dye conLentration?

Paper 24 · ACT April 2019 · Form Z15 · Science Test

If a trial had been done in Study l at an initial A3 con- centration of 4.0 rnglL, Ihe formazan concentration would most likely have been closest to which of the following

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Based on the results of Study 2, which tea eKtract was Tnost effective at reducing the number of ROM in rat heart tissue?

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Consider the results of the triKils in Study I for the 4 antioxidants ai any given initial antioxidant concen- tration. For which of the following reasons could these results be validly compared? The solutions in ihe test lubes had,, the same initial concentration of malondialdehyde. 150 100 50 water only T2 T3 T4 T5

Paper 24 · ACT April 2019 · Form Z15 · Science Test

In which 8tudy was the incubation temperature of the sollltiolls higher, and in which ,£tudy was the incuba- tion timc for the solutions longer? temperature time Study I Study I Study I Study 2 Study 2 Study I Study 2 Study 2 treatment Figure 2 Figure 2 adapted from Vadivel S. Kumaran, Karpagavinayagam Arulmathi, and Periandavan Kalaiselvi. "Senescence Mediated Redox Imbalance in Cardlac Tissue.. Antioxidant Rejuvenating Potential ol Grgen Tea Extract. @2009 by Elsevier Inc_

Paper 24 · ACT April 2019 · Form Z15 · Science Test

suppo.se that in a new study the procedures of Study 2 are repeated exccpt that the rats receive only 5090 of the daily d05e of each ica extract that the rats received in Study 2. Would the malondialdehydc concentration measuied for Tl more likely be higher OT lower than the value for Tl trihown in Figure 2 9

Paper 24 · ACT April 2019 · Form Z15 · Science Test

In Study I, each test tube was incubated for 30 min to allow sufficient time for the ROM to react with the: antioxidant. tea extract. ACT-Z15 47 GO ON TO THE NEXT PAGE. 40000000004 Passage Vl In the yeast Saccharomjces ceyevisiae, the function of meiogis is to divide a diploid cell into 4 haploid cells called spores. During meiosis, the 2 copies of a chromosome, or hopnologs. undergo DNA replication (when each homolog becomes a linked pair of sister chromatids} Followed by 2 rounds of chromosome segregafion (separation into dif- ferent cells) called Meiosis I and M¢in8is II. The figure shows the homologs of a p£wticular chromosome during meiosis in a wild-type S. cerevi.¥iae strain and also in 2 mutant S. cerevisiae strains (Mutant A and Mutant B) each having a differcnt mutation that affects meiosis. homologs DNA replication 8lSter chromatids of a homolog Meiosis I Meiosis I Meiosis I Meinsis Il Meiosis Il M¢.iosis ll 00 wild-type strain Mutant A strain Muwii B str&'n Note,, Each cell shown after Meiosis II is an S. cerev'i5iae spore, although the genetic content of the cells may vary. Figure adapted Irorn Andrew Murray and Tim Hunt, The Cell Cycle. @1993 by W. H. Fregman and Company. ACT-Z15 48 GO ON TO THE NEXT PAGE. 40000000004

Paper 24 · ACT April 2019 · Form Z15 · Science Test

According to the figure, how many cells are direcily produced by Meiosis l in the Mutant A S. c'erevtsioe strain, and how many cells are directly produced by Mciosis I In the Mutant B S. cÉrevi.viae strain? Mutant A str¢iin Mutant B strain

Paper 24 · ACT April 2019 · Form Z15 · Science Test

According to the figure. does rnciosis in ihe Mut£int B LerevEsiae strain produce as many .spore8 as does meiosis in a wild-type S. cerevisiae strain? Yes- 4 Mutant B S. cerek'isiae sporeq are produced.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Suppose that 10 chrornosomes were found ill each of the SPOTes of another species of yeast. Species X. Assuming thaL there were no mutations that affected the formation of the spores, what is the diploid number of chromosomes of Spccies X ?

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Based on the figure, which of the 2 mlltant S. cere- Iiisiae strains, if either, ha8(have) a mutation that affects Meiosis l ? Neither Ihe Mutant A strain nor the Mutant B strain

Paper 24 · ACT April 2019 · Form Z15 · Science Test

The depiciion of meio%i8 in th¢ figure for which of the three S. cereipisiae slrains, if any, is consistent with the statement "DNA replication occurs between Meiosis I and Meiosis 11,: 9 Meiosis l.

Paper 24 · ACT April 2019 · Form Z15 · Science Test

Based on the figure: for a wild-type S. cerek'i,giae strain, the total mas5 of DNA per cell i.s greatest at a tiTne between the: end of interphase and the start of DNA replication. end of DNA Teplication and the start of Meiosis I. end of Meiosis I and the start of Meiosi% II. end of Meiosis II and the staTt of interphaqe. END OF TEST 4 STOP! DO NOT RETURN TO ANY OTHER TEST. ACT-Z15 49 April 2019 (EXT) Section 1 Section 2 Section 3 Section 4 ENGLISH MATH READING SCIENCE