AAMC MCAT Practice Exam 1: Questions and Answers with Verified Solutions, Exams of Advanced Education

Download AAMC MCAT Practice Exam 1: Questions and Answers with Verified Solutions and more Exams Advanced Education in PDF only on Docsity!

AAMC MCAT Practice Exam 1 | Questions And Answers

With Verified Solutions

In the chromatography of the reaction mixture, water absorbed on cellulose functioned as the stationary phase. What was the principal factor determining the migration of individual components in the sample? A) Hydrogen bonding B) Solute concentration C) Stationary phase concentration D) Thickness of paper ✔✔A) Hydrogen bonding The answer to this question is A because the relative amount of hydrogen bonding to the stationary phase will determine the relative rate of migration of the various components in the sample. What assumption is being made if scientists conclude that aspartic acid was formed by the prebiological synthesis in the passage? A) Aspartic acid is unstable at temperatures below 150 degrees C. B) All of the malic acid underwent the dehydration reaction to form fumaric/maleic acid. C) Compound A and cyanide were available on primitive Earth. D) The reaction between ammonia and fumaric acid was catalyzed by the presence of water. ✔✔C) Compound A and cyanide were available on primitive Earth. he answer to this question is C since, in order for the experimental reaction sequence to be relevant to the primordial formation of aspartic acid, the starting materials used (Compound A and cyanide) are assumed to have been available. According to the developed chromatography plate shown below, what is the approximate Rf value of aspartic acid? aspartic acid = 2 solvent front = 10 A) 0. B) 0. C) 5 D) 10 ✔✔The answer to this question is A (0.20) because Rf is the ratio of the distance travelled by the analyte relative to the solvent front during a chromatographic separation. Aspartic acid travelled two units, while the solvent front travelled ten units, giving an Rf of 2/10 = 0.20 for aspartic acid. Which of the following statements does NOT correctly describe the dehydration of malic acid to fumaric acid and maleic acid?

A) The reaction occurs most readily with tertiary alcohols. B) The reaction involves the loss of a water molecule. C) The reaction has a carbocation intermediate. D) The reaction is stereospecific. ✔✔D) The reaction is stereospecific. The answer to this question is D because the fact that both fumaric and maleic acid are produced means that the dehydration of malic acid is NOT stereospecific. What type of functional group is formed when aspartic acid reacts with another amino acid to form a peptide bond? A) An amine group B) An aldehyde group C) An amide group D) A carboxyl group ✔✔C) An amide group The answer to this question is C because the functional group that forms during peptide bond formation is known as an amide group. If 2 - pentanol replaces 1-pentanol in the reaction shown in Figure 3 (SN2), the rate of substitution is less because: A) the C-O bond in 2-pentanol is stronger than the C-O bond in 1-pentanol. B) there is a competing elimination reaction that slows the rate of substitution. C) there is more steric hindrance at the oxygen atom in 2-pentanol than in 1-pentanol, making protonation less likely. D) there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of 1 - pentanol. ✔✔D) there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of 1-pentanol. The answer to this question is D because the rate of substitution of protonated alcohols is subject to steric hindrance. This inhibits the ability of nucleophiles to collide with the reacting electrophilic center and slows the rate of reaction. If a solution containing the compounds shown in Figure 4, is injected into a gas-liquid chromatograph, the first peak observed in the gc trace is attributable to which compound? A) Methyl- 2 - butanol B) Methyl- 2 - butene C) Chloro- 2 - methylbutane D) Bromo- 2 - mehtylbutane ✔✔B) Methyl- 2 - butene The answer to this question is B because 2-methyl- 2 - butene will exhibit the lowest molecular weight and also the weakest intermolecular forces of attraction. This substance will therefore migrate the fastest and be the first peak in the gas chromatograph (gc) trace.

A) Chlorinating the CH3 group B) Diluting the solution C) Adding concentrated HCl (aq) D) Adding a drop of basic indicator ✔✔C) Adding concentrated HCl (aq) The answer to this question is C because HCl is a strong acid that will increase the amount of H+ in solution and thus decrease the percentage of CH3CO2H that ionizes. When the current in the micro-robot's circuit increases and the resistance of the circuit remains constant, the voltage of the circuit: A) decreases B) increases C) is constant D) is zero ✔✔B) increases V = IR The answer to this question is B because according to Ohm's law, current is equal to voltage divided by resistance. If current increases and resistance is constant, then voltage increases as well. Knowing that the speed of light in the vitreous humor is 2.1 × 108 m/s, what is the index of refraction of the vitreous humor? (Note: The speed of light in a vacuum is 3.0 × 108 m/s.) A) 0. B) 1. C) 2. D) 3.0 ✔✔B) 1. n = c/v The answer to this question is B because the index of refraction of a medium is equal to the ratio of the speed of light in vacuum to the speed of light in the medium, thus it is equal to (3.0 x 108 m/s)/(2.1 x 108 m/s) = 1.4. The intensity of the radiation emitted by the oxygen sensor is directly proportional to the: A) propagation speed of the radiation B) wavelength of the radiation C) polarization of photons emitted D) number of photons emitted ✔✔D) number of photons emitted The answer to this question is D because the energy of electromagnetic radiation is directly proportional to the number of photons, and the intensity of electromagnetic

radiation is defined as energy emitted per unit time. Thus, intensity is directly proportional to the number of photons emitted. What is the energy of the photons emitted by the LED at a frequency of 610 THz? (Note: h = 6.6 × 10-34 J·s) A) 9.2 × 10-12 J B) 1.6 × 10-16 J C) 1.1 × 10-18 J D) 4.0 × 10-19 J ✔✔D) 4.0 × 10 - 19 J The answer to this question is D because the energy of a photon of frequency 610 THz is equal to 6.6 x 10-34 J•s x 610 x 1012 Hz = 4 x 10-19 J. What percentage of standard atmospheric pressure is the pulse pressure of a healthy adult? The maximum and minimum blood pressures of a healthy adult are about Ps = 120 mmHg and Pd = 75 mmHg. Pp = Ps-Pd A) 10% B) 6% C) 2% D) 1% ✔✔B) 6% The answer to this question is B because the pulse pressure in a healthy adult is (120 −

75. mmHg = 45 mmHg, and so the percentage is 45 mmHg/760 mmHg = 6%. What fraction of a O-15 sample decays in 10 min? "The location of internal organs where changes in the calcium content occur can be found by placing positron-emitting isotopes such as O-15 (with a half-life = 2 min) into the patient's bloodstream) A) 1/ B) 9/ C) 3/ D) 31/32 ✔✔D) 31/ The answer to this question is D because the half-life of 15O is 2 minutes; thus, 10 minutes = 5 half-lives. Therefore, only (1/2)5 = 1/32 of the sample will be left after 10 minutes, while 31/32 of the sample will decay.

The answer to this question is C because the molecule contains mainly acidic side chains that were deprotonated and negatively charged at high pH. This inhibited aggregation due to electrostatic principles. At low pH these groups are neutral and this allowed aggregation. Why is the velocity of blood flow slower in capillaries than in arteries? A) Capillary walls are more elastic than arterial walls. B) Capillaries have less resistance to blood flow than arteries. C) The total cross-sectional area of capillaries exceeds that of arteries. D) Blood pressure is higher in the capillaries than in arteries. ✔✔C) The total cross- sectional area of capillaries exceeds that of arteries. A1v1 = A2v The answer to this question is C because the high number of capillaries in the body means that the total cross-sectional area of these vessels is larger than any other vessel type in the circulatory system. This causes the velocity of the blood to decrease. Which of the following types of orbitals of the central atom is involved in bonding in octahedral compounds? A) sp B) sp C) p D) d2 sp3 ✔✔D) d2 sp The answer to this question is D because octahedral compounds have six σ bonds and no lone pairs. According to valence bond theory, the central atom requires the hybridization of six atomic orbitals, d2sp3. The term "ideal gas" refers to a gas for which certain assumptions have been made. Which of the following is such an assumption? A) The law PV = nRT^2 is strictly obeyed. B) Intermolecular forces are infinitely large. C) Individual molecular volume and intermolecular forces are negligible. D) One gram-mole occupies a volume of 22.4 L at 25 degrees C and one atmosphere pressure. ✔✔C) Individual molecular volume and intermolecular forces are negligible. The answer to this question is C since a property of an "ideal" gas is that it is composed of particles that have negligible volume and do not exert intermolecular forces. The production of a variety of opsins functions to: "Additional opsin based receptors are expressed in specialized cone cells"

A) increase sensitivity to low light B) enable the detection of different colors C) ensure fast recovery of 11-cis retinal after exposure D) increase refractive index of the eye lens ✔✔B) enable the detection of different colors The answer to this question is B. The wavelength of light absorbed by a molecule depends on its structure, and so the production of a variety of structurally related opsins functions to enable the detection of different colors. The environment of the retinal binding site is most likely: "Rhodopsin is composed of opsin, a family of seven helix transmembrane proteins, and a covalently attached coenzyme, retinal." A) hydrophilic B) positively charged C) negatively charged D) hydrophobic ✔✔D) hydrophobic The answer to this question is D because retinal is composed of mainly carbon and hydrogen, making it largely hydrophobic. The source of the phosphate groups that are added to rhodopsin is: "Wild-type or variant rhodopsin was reconstituted with 11-cis-retinal and phosphorylated by rhodopsin kinase in the presence of ATP before examining arrestin binding" A) arrestin B) rhodopsin kinase C) ATP D) all-trans-retinol ✔✔C) ATP The answer is C because the requirement of ATP for kinase activity implies the phosphate groups come from ATP. What are the hybridization states of the carbon atoms involved in the conversion of trans to cis retinal? A) sp B) sp C) sp D) sp3d ✔✔B) sp he answer to this question is B because the reacting carbon atoms are both central to AX3 systems with 3 bonded atoms and no lone pairs. The preferred geometry for such

Figure 1B - pH 4 A) 2 B) 10 C) 200 D) 1000 ✔✔D) 1000 The answer to this question is D because the pH scale is logarithmic (pH = −log([H+]). A difference of 3 pH units corresponds to a 103 = 1000-fold difference in proton concentrations. Which type of bond is formed by glycogen synthase upon release of UDP? A) α-1,4-Glycosidic bond B) α-1,6-Glycosidic bond C) β-1,4-Glycosidic bond D) β-1,6-Glycosidic bond ✔✔A) α-1,4-Glycosidic bond The answer is A because the bond that is formed by glycogen synthase is the main chain linkage of glycogen, which is an α-1,4-glycosidic bond. UDP release means that only glucose was added. In addition to glucose, what other monosaccharide is part of the UDP-glucose structure? A) Xylose B) Fructose C) Ribose D) Arabinose ✔✔C) Ribose The answer is C because UDP contains uridine, which is a nucleic acid used in RNA. The structure of RNA contains ribose. Addition of laforin to the reaction mixtures used to generate the data in Figure 2 will result in: "LBs contain a much larger amount of covalently-linked phosphate compared to normal glycogen." A) a decrease in the intensity of the band representing WT without glucosidase when visualized with 14C decay. B) an increase in the intensity of the band representing WT without glucosidase when visualized with 14C decay. C) a decrease in the intensity of the band representing WT without glucosidase when visualized with 32P decay.

D) an increase in the intensity of the band representing WT without glucosidase when visualized with 32P decay. ✔✔C) a decrease in the intensity of the band representing WT without glucosidase when visualized with 32P decay. The answer is C because laforin is an enzyme that removes phosphate from glycogen. Presumably, the removal of phosphate prior to gel electrophoresis will result in a smaller band corresponding to 32P incorporation. The radioactive decay described in the passage results in the formation of which two atoms? "The reaction products were separated by SDS-PAGE and visualized by autoradiography that detects the products of B- decay." C-14 and P- 32 A) N and S B) B and Si C) B and S D) N and Si ✔✔A) N and S The answer to this question is A because the type of radioactive decay is b-1 so a neutron is converted into a proton, which results in carbon becoming nitrogen and phosphorus becoming sulfur. Compared to normal glycogen, the amount of what type of bond is decreased in Lafora bodies? "Lafora disease is a fatal progressive epilepsy that is characterized by the formation of deposits of sparsely branched, insoluble glycogen-like polymers called Lafora bodies" A) Phosphomonoester B) Phosphodiester C) a-1,4-glycosidic bond D) a-1,6-glycosidic bond ✔✔D) a-1,6-glycosidic bond The answer D because it is stated in the passage that the lack of branching is a characteristic of Lafora bodies. Branching occurs through an α-1,6-glycosidic bond in glycogen. Each of the following equations shows the dissociation of an acid in water. Which of the reactions occurs to the LEAST extent? A) HCl + H2O → H3O+ + Cl− B) HPO42− + H2O → H3O+ + PO43− C) H2SO4 + H2O → H3O+ + HSO4−

Which of the following most likely will occur if a homogeneous catalyst CANNOT be separated from the products at the end of a reaction? A) The catalyst will become heterogeneous. B) The products will be contaminated. C) The reaction will not occur. D) The reaction rate will speed up. ✔✔B) The products will be contaminated. The answer to this question is B. If a homogeneous catalyst cannot be separated from the products at the end of a reaction then the products will be contaminated with the catalyst. How will the rate of a catalyzed reaction be affected if the solid catalyst is finely ground before it is added to the reaction mixture? A) The rate will be faster because a greater mass of catalyst will be present. B) The rate will be faster because a greater surface area of catalyst will be exposed. C) The rate will be slower because the fine catalyst particles will interfere with product formation. D) The rate will remain the same because the mass of catalyst will be the same. ✔✔B) The rate will be faster because a greater surface area of catalyst will be exposed. The answer to this question is B because grinding a heterogeneous catalyst increases the amount of catalyst available to the reaction and therefore increases its rate. A student can most effectively increase the current passing through the circuit in Figure 2 by doing which of the following? A) Using electrical wire with a smaller diameter B) Increasing the temperature of the electrical wire C) Decreasing the concentrations of Xn+(aq) and Ym+(aq) D) Replacing the lightbulb with one that has a resistance of 0.2 Ω ✔✔D) Replacing the lightbulb with one that has a resistance of 0.2 Ω The answer to this question is D because according to Ohm's law, current is equal to voltage divided by resistance. In order to increase the current when the voltage fixed, the resistance must be decreased, such as by replacing the light-bulb with one that has a resistance of 0.2 W instead of 0.5 W. When a strip of Zn is placed in a beaker containing 0.1 M HCl, H2(g) evolves. If a strip of Al is placed in a beaker containing 0.1 M HCl, does H2(g) evolve? A) Yes; Al is reduced and H+(aq) is oxidized. B) Yes; Al is oxidized and H+(aq) is reduced. C) No; Al is reduced and Cl-(aq) is oxidized

D) No; Al is oxidized and H2O(l) is produced. ✔✔B) Yes; Al is oxidized and H+(aq) is reduced. The answer to this question is B. Since a new solid forms when Al(s) is mixed with Zn2+(aq), it is reasonable to assume that Al(s) is more susceptible to oxidation than Zn(s). Assume that a circuit similar to that in Figure 2 is set up in which X = Al, Xn+ = Al3+, Y = Cu, and Ym+ = Cu2+. Which of the following reactions will occur?* A) 2Al3+(aq) + 3Cu(s) → 2Al(s) + 3Cu2+(aq) B) 3Al3+(aq) + 2Cu(s) → 3Al(s) + 2Cu2+(aq) C) 2Al(s) + 3Cu2+(aq) → 2Al3+(aq) + 3Cu(s) D) 3Al(s) + 2Cu2+(aq) → 3Al3+(aq) + 2Cu(s) ✔✔C) 2Al(s) + 3Cu2+(aq) → 2Al3+(aq) + 3Cu(s) The answer to this question is C because this response depicts the balanced chemical reaction that occurs when the four substances [Al(s), Al3+(aq), Cu(s), and Cu2+(aq)] are mixed. A circuit similar to that in Figure 2 is set up in which X = Pb, Xn+ = Pb2+, Y = Cu, and Ym+ = Cu2+. Will an oxidation-reduction reaction occur spontaneously?* Pb2+(aq) + 2e- → Pb(s) E°red = - 0.127 V Cu2+(aq) + 2e- → Cu(s) E°red = +0.339 V A) No; E°cell = - 0.212. B) No; E°cell = +0.212. C) Yes; E°cell = - 0.466. D) Yes; E°cell = +0.466. ✔✔D) Yes; E°cell = +0.466. The answer to this question is D. A spontaneous reaction occurs when E° is greater than zero, and this occurs if the oxidation of Pb(s) is combined with the reduction of Cu2+(aq), resulting in a net E° of +0.466 V. A circuit similar to that in Figure 2 is set up. It has a potential of 2.0 V. Assume that the resistance in the circuit is negligible compared to that of the lightbulb. Approximately how much current passes through the lightbulb? Resistance = 0.5 ohms A) 0.5 A B) 1.0 A C) 2.0 A D) 4.0 A ✔✔D) 4.0 A

D) reasonableness of small groups compared to large groups ✔✔D) reasonableness of small groups compared to large groups The answer is D, because the question describes a small group in which people "obey an authoritarian, charismatic leader." In the passage, however, the author claims that a "great multitude" is more likely to succumb to "unreflective enthusiasm... than is a small meeting" (paragraph 2). So if the cults that the question describes are small groups of fewer than 100 members, this would weaken passage claims about the more considered behavior of small groups when compared to larger ones. CARS: The passage assertion that a dead poet is "owned without opposition" (paragraph 3) probably means that: A) the poet is no longer able to challenge the public's response to the poet's life and work B) other writers will no longer oppose the poet's views C) readers will no longer intrude on the poet's private life. D) the poet's admirers will buy up all the poet's books and relics ✔✔A) the poet is no longer able to challenge the public's response to the poet's life and work The answer is A, because, before claiming that a dead poet is "owned without opposition," the author writes, "if you [have] the misfortune to be dead as well as famous, matters are less under your control... The dead poet has been ingested by his readers; from now on he will be read, admired, and loved in a different way." "Ingested by his readers" clearly implies that readers have taken over the subjectivity of the dead author. The dead author is unable to determine how he is perceived and represented by fans. CARS: Which of the following facts cited in the passage gives the strongest support for the claim that Portuguese liberals were in the minority politically? A) The queen and her son were opposed to them. B) Several important liberals were jailed by John. C) The Inquisition was still active in Portugal. D) The commoners were politically conservative. ✔✔D) The commoners were politically conservative. The correct answer is D, because paragraph 2 defines the components of the commoners as a highly inclusive segment of the populace: "peasants, craftspeople, tradespeople, soldiers." The aggregate number of their ranks would, therefore, vastly outnumber the relatively few groups of individuals (including scientists and poets) that comprise the liberal faction alluded to in the passage (paragraph 3). CARS: The author's analysis of image-making rests on the assumption that a capitalist society separates:

A) advertising from entertainment B) private perception from social order C) diseases that afflict society from their cures D) free political choice from free economic consumption ✔✔B) private perception from social order The answer is B. In paragraph 3, the author distinguishes the aesthetic approach from the instrumental approach to image-making. The first is matched up with private perception ("Cameras capture and 'fix' impressions from that mythical space known as private perception"); and the second linked to the social order ("cameras also arm vision in the service of power - of the state... ."). In the next paragraph, this dichotomy is described as a capacity to "subjectify" reality and to "objectify it." CARS: Recent technological developments like high-resolution satellite imagery and diagnostic positron emission tomography (PET scans) have refined and extended the camera's capacity to provide information. Which passage assertion does this information support most strongly? A) Cameras can illuminate the private, personal lives of individuals. B) Capitalist consumption requires the unlimited production of images. C) Cameras are means of appropriating reality and making it obsolete. D) Photography can be used to both control and benefit society. ✔✔D) Photography can be used to both control and benefit society. Satellite images of offenders such as speeding drivers could, for example, be used to both control (by penalizing offenders) and benefit society (by protecting them from offenders); PET scans could be used to benefit society by revealing information about the human anatomy. Option D is the correct answer. CARS: Which of the following findings would most weaken the author's explanation of the observed effects of class-size reductions? A) Class-size reductions in the early grades are effective regardless of whether the teachers use methods well suited to small classes. B) Raising teacher salaries produces much greater improvements in student performance than does reducing class sizes at all grade levels. C) When teachers emphasize personal interactions with students, academic achievement typically improves regardless of class size. D) Academic achievement levels are often low even when teachers use methods well suited to small classes. ✔✔A) Class-size reductions in the early grades are effective regardless of whether the teachers use methods well suited to small classes. The answer is A, because the author's explanation for improved performance in small classes rests on the fact that "some teachers, who already use methods well suited to smaller classes, do very well when they are actually given small classes." If, however, early grades showed improvements in student performance in smaller classes

author seeks to erase this boundary, the author must believe that such a boundary has been erected and enforced to begin with. CARS: Which of the following best describes the author's attitude toward the fact that the original paint of an architectural element has typically been painted over not just once but several times in the course of history? A) It makes much of architectural paint research guesswork. B) It is what makes architectural paint research such a robust source of information. C) It indicates a difference in status between easel/wall painters and house painters. D) It is something that education about architectural paint research might prevent in future. ✔✔B) It is what makes architectural paint research such a robust source of information The answer is B, because the author says that "the accumulation of successive paint layers on architectural elements is now regarded as an important archaeological resource" (paragraph 3). The author contends that the repeated application of paint finishes allows researchers to study a progressive history of the use of the "development and use of the building long after the last structural alteration has been completed" (first paragraph). CARS: Why does the author quote the letter which states "'Today my chambers painted a fine blue'" (paragraph 5)? A) To return to a point made earlier in the passage about blue paint B) To show that interior decoration has been as important to occupants as exterior decoration C) To illustrate the value of consulting documentary evidence as part of architectural paint research D) To suggest the danger of using one type of evidence without corroboration by another type of evidence ✔✔C) To illustrate the value of consulting documentary evidence as part of architectural paint research The answer is C, because the author quotes the letter as part of the argument that good research is holistic, drawing on all available sources. The author uses the example of the letter as an example of a situation in which a document may be more useful that "sophisticated pigment analysis" (when one wishes to date "a significant paint layer"). CARS: Which of the following approaches to research does the author most support? A) Experimental B) Theoretical C) Statistical D) Holistic ✔✔D) Holistic The answer is D, because the author argues for the incorporation of multiple sources of evidence in order to plan and execute good architectural paint research; the author

points to "the importance of collating and synthesizing all existing evidence" (paragraph 5). This supports the choice of D, "holistic." CARS: The single change to the observed ritual at Mariani that would most weaken the author's distinction between Mariani and Nansoucri voodoo would be a situation in which: A) all possessions were outwardly apparent B) rituals included elements of danger C) audience members were invited to dance with the hounsis D) one or more audience members became possessed ✔✔D) one or more audience members became possessed The answer is D, because the author's distinction between the two voodoo forms turns on the fact that the Mariani session is a "theatrical" session, in which the audience essentially watches the action from a "distance... that disallows real transformation (inadvertent possession)" (paragraph 3). Thus, if audience members at Mariani did indeed become possessed, the author's distinction between Mariani voodoo and the more participatory, ritual form of voodoo at Nansoucri would break down. The author uses the term "culture as commodity" to characterize which aspect of Haitian voodoo? I. The charging of admission at voodoo sessions II. The molding of voodoo to fit audience expectations III. The sale of voodoo trinkets and other artifacts A) I only B) III only C) I and II only D) II and III only ✔✔C) I and II only The answer is C, because both options I and II are correct, while option III is not. The author explains that the "outsider" to Haiti expects voodoo to be "almost synonymous" with the country itself. According to the author, this powerful "identification" of Haiti with voodoo leads to "culture as commodity"—or the outsiders essentially being able to get what they want from voodoo. In paragraph 3, the author describes a form of voodoo that is staged for outsiders and which the audience pays admission to watch; this supports option I. Also, in paragraph 3, the author contends that the form of voodoo witnessed at Mariani "confirms the popular expectation of 'scary voodoo'"; this supports option II. A man with a CRC mutation that results in the synthesis of HSP110ΔE9 and a woman that does not carry this mutation in any of her tissues have a child. What is the percent chance that the child will inherit the CRC mutation? A) 0% B) 25% C) 50%