ACT Past Papers with Answers

Based on Table 2, a P. sativum plallt with I dotnillaDt allele for each of the 4 genes will have which of the following phenotypes? stems stems stems PuLple flowers, green pods, round seeds, tall stems

In l of the crosses listed in Table 3, for each trait, the offspring were split evenly bctween the 2 possible phenotypes. In this cross, the genotypes of the female parellt and the male parent were, respectively: aaBbDdee alld aaBbDdee. aaBbDdee and AabbddEe.

Based on the informatiou presented, all of the off- spring of Cross 4 had yellow pods because each received.. its male parent. Lts male parent. its male parellt. Allele E from its female parent and Allele e frotn its male parent.

In Cross 3, what percent of the offspring had Geno- type BB ? Olo AGT-68A 39 GO ON TO THE NEXT PAGE. 40000000004 Passage 11 jLTure I showg the life cycle of the Etialaria parasite. Ga7netocytes and sporozoites ale 2 forms of the parasite. human host chamber pipe mosquito trap tent Note: Dotted lin2s indicate mosquito netting.. Figure 2 mosquito host In the first trial 100 uninfecled mosquitoes were releaged into the chamber. Thirty minutes later the number of mos- qllltoes attractcd to each subject was"determined. This PTO- cedllre was repe&ted in 11 more trials until all subjects had been tested. Then, for each group, the average numbeT of mosquitoes attracted to a subject was calculated (see Figure 3). All infected subjects were then treated to cure their sporoEOlte OI gametocyte infections. Figure I For the parasite to survive, mosquitoes must bite hufflans infected with gametocytes. Therefore, 2 studies were conducted to deterniine whether mosqllltoes are most attracted to humans infected wÈth gametocytes. 12 10 Study I Three groups (Groups X, Y, and Z). each wit 12 human subjects (Subjects 1-12), were.identified (see Table l). Table I GTOUP Malaria infection . status of subjects Fioure 3 Group Uninfected Sporozoites present Gairietocytes present Study 2 The piocedllre from Study I was repeated with Group X subjects and the cured subjects from nJroups Y and Z. Figure 4 Silows the proportion of responsive mos- quitnes (tb.ose cau(rht in a trap) that wtre ?ttractPi to thi Group Z subjects before treat￿eTht and after being cured of their gametocyte infections. Three subj ects-one from each J(T oup-rested in sepa- rate, but identical, tents of mosquito netting attached to the satne cet]tral chamber. A moÈquito trap was inserted between the chamber and each ter]t to capture any mosqui- toes trying to enter the tent (see Figure 2). ACT.68A 40 GO ON TO THE NEXT PAGE.

OxlO HI 14 14 AGf-68A 47 GO ON TO THE NEXT PAGE. 40000000004 Passage Vl ' The same procedure was used with various initial volumes of NO and 02 (see Table l ). At constant temperature and pressure, the ratio in which the volumes of gases react and form products is indicated by the balanced chemical equation for the reac- tion. For exarnple, considei the balanced chemical equation for hypothetical Gases A. B, and C: Table I A+2B4C Volume ofNO (ML) Volume ofo, (ML) Final volume Syringe I contsnts (ML) At constant tempeiature and PEessure, l L of Gas A will react with 2 L of Gas B to form l L of Gas C. Trial (ML) 20 40 20 30 20 20 40 10 30 40 50 30 10 20 40 20 20 Students did experiments at constant room tempeTa- tllre and pressure to determine ihe ratio in which nitric oxide (NO) and O (either pure, 01 from air) react to forni nitrogen, dioxide (NOJ. 30 10 Experiment I Two glass syringes (SyTinges I and II) were lubricated so their plungers Wollld move freely. Then, 20 ML of NO was introduced into empty Syiillge I through its tip and the tip was closed. Next, ?0 of 02 was introduced into empty Syringe II through its tip and the tip was closed. The syringes were then attached to each other and the tips were opened. The plunger of Syringe II was pushed to the bottom (emptying its content into Syringe D and its tip was closed. After the reaction was complete, the final voluine of gas in Syrintre I was recorded and its contents were ana- lyzed (see Figure l). Syringe I Syiillge tt NO NO and O, NO2 plus any UllTeacted NO or O Figure I FigLJre 1 adapted from Donald D. DuPré, "A Simple Demonstration of the Law of Corttbining Volumes.. ¢m 993 by Division of Chemical Educa- tion. Inc. American Chemical Sociely. ACT-68A 48 GO ON TO THE NEXT PAGE. 40000000004 Experiment 2 The procedure from Experiment I was used to test 20 ML of air (instead of 02) mixed with vaTiOUS amounts of NO (see Table 2). Table 2 Volll]ne ofNO (ML) Volume of air Fin¥AI volurne SyriDge I contents (ML) Tiial (ML) (nL) '0 NO, Other gases 16 16 16 16 20 20 20 20 22 24 32 48 16 32 24

In Studies J and ? which group-GEoup X OL" Group Y-tnore likely served as the standard of com- parison allowing the researchers to compare Llie resulis fil," liioiip Z from Study I to the results for Group Z from Study 2 ? r. Group X, because the infection status of the Group X subjects was different in Study l and Study 2. Group X subjects was the sanie in Study l and Study 2. Group Y subjects was different in Study l and Study 2. Group Y subjccts was the same in Study l and Study 2.

Which of the following procedures was most likeLy employed to ensure that the mosquitoes were attracted to a specific subject rather than to a specific tent? each tent in each trial Releasing a dRfferent number of Mosquitoes into each tent in each trial in each trial in each trial 41 GO ON TO THE NEXT PAGE. ACT-68A 40000000004 Passage 111

Based on Scientist I's discussion, petroleurn deposits would most likely be found at oi near locations where: an ocean recently formed where none had existed in tbe past. an ocean had existed at some time in the past. Petroleufrn (crude oil) is brought to Earth's surface from large underground. deposits that aIe mogtly

Which of the followincF diagiams is most consistent with Scientist 2's description of the formation and mitsraiion of petrolcum? (Note: Diagrams are not to scale.)

Based on the scientists, discllssions. which of the fol- lowing statements describes the 2 physical properties of petroleum that are most irnportant in facilitating its movetllellt from the location at which it forms to the location at which it accumulates in a I￿ge deposit? Petroleum is a: moves through. moves through. solid that is more dense than the'material that it moves through. solid that is less dense thau the material that it moves thTough.

Based on Scientist 2's discussion, which of the follow- ing compounds is involved in the formation of petroleum?

According to Figure 2, during Reactloll 2 without a agnetic field, the fo PM at 10 min was approximately: witiiollt field 40 30 20 10 magnetic

According to Figure 3, in Reaction 3, how did the addition of a magnetic field affect the yield of pure Fe metal? At 20 min, the yield obtained with a matsnetic field was about:

Suppose that Figure I had instead been plotted as per- cent of Trzetal oxide (Yo MO) versus time: mass of metal oxide ]nass of metal oxide + amss of metal %MO= xlOO the yield obtailled withollt a ma(wne.tic field. Which of the following graphs best shows how Figure J wouId have appeared? the yield obtained without a magnetic field. field. field. Key with magnetic field without magnetic field

For a photon to fiee an electron from Ca, the photon's frequency must be at least.. 14 . 1.15 x 10 Hz. 14 14 14

Based on Figure I, for electrons ejected fro￿ Pt by 14 photons havingf - 28.0 x 10 Hz, K Based on Figure l and Table I, the fT of Metal X is ost likely closest to which of the following. 14

Photons having f = 11.8 x 10 Hz and photons having 14

In Experiment 2, from trial to trial. as the volume of NO was increased, the volume of NO2 prodllced: increased only. increased, then remained constallt.

In which of the trials of Experiments l and 2 were all of the gases in the syriuges completely. converted to . Triall

The reactant that is used up first in a reaction is called the limiting reagent, What was the limiting reagent in Trial l ?

Based on Experiment l. the balanced chemical equa- tion for the reaction of NO and 02 to form NO2 IS: 2N0 + 02 -> 2N0 ACT-68A 49 GO ON TO THE NEXT PAGE. Passage.Vll SIudy 2 A physiGal pendulum is an object that is suspended vertically from a ricTid support (see example kn Fi(rure l). rod Tiials 6-10, each pendlllum was a 1.0 kg thin, flat circular plate with D = 0.20 m (sce Figure 3). rod rod •CM CM CM pl&te plate front view side view front view side view Figure I Figure 3 L is the distance between the rod (the rigid support) and the penduluin's center of mass (CM). When the pendulutll is displaced from its eqllilibrium position and then released, it oscillates (swintrs back and forth) about the rod, which acts as the axis of rotatiOII. Each pendulum had a different L (see Table 2). Table 2 Students tested several types of physical pendulllll]s. In each trial, first, they computed the ￿0￿ent of inertia, I, in kilogram meters (kg m ), of a pendulum. (l is a measure of the mass of a pendulum and how the mass is distrib- uted.) Next, they displaced the pendulum slightly fToD] its equilibrillm position, rcleascd it, and measured the time, in seconds, it took the pendulum to oscillate through 20 cycles (I cycle is I round-trip back and forth). Finally, they computed the pendulum's average period, P (the aver- age time it took to complete I cycle). Tiial (m) (10-, kg m,) (sec) 10 Study I In Trials 1-5, each pendulum was a 1.0 kg solid sphere with a diaineter, D, of 0.20 m (see Figure 2). rod Srudy 3 In Trials 11-15, each pendulum was a 1.0 kg thin, spherical shell with D = 0.20 m (see Figure 4). rod rod CM soIid sphere solid sphere spherical shell spherical shell front view side view front view side view Figure 2 Figure 4 Each pendulum, however, had a different L. The results are showll ill Table l. Each pelldulum had a different L (see Table 3). Table I Table 3 Trial (m) (10-, kg m,) (sec) Trial (m) (10-, kg m,) (sec) 12 13 14 .15 ACT-68A 50 GO ON TO THE NEXT PAGE. 000000000

In each study, ag the distance between the CM and the horizontal rod increased, the moment of inertia: increased only. varied, but with no geneIal trelld. remained the same.

Object A and Object B each con8lSts of a pair of spheres connected by a rigid wire of insignificant mass. The 4 spheres are identical to each other. Each object is suspended vertically fro￿ a support at a dis- tance L above the object's CM, as shown in the figure below.

In Trial 4. approxitnately how long did it take the pen- dulum to complete 20 cycles?