2024 AAMC MCAT PRACTICE EXAM 1 WITH CORRECT ANSWERS, Exams of Advanced Education

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2024 AAMC MCAT PRACTICE EXAM

1 WITH CORRECT ANSWERS

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 - CORRECT ANSWERS-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 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 - CORRECT ANSWERS-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. Which research methodology involves the extended, systematic observation of a complete social environment? A) Comparative methods B) Ethnographic methods C) Experimental methods D) Survey methods - CORRECT ANSWERS-B) Ethnographic methods Ethnographic methods are accurately described in the question as involving systematic observation of a complete social environment. comparative methods - CORRECT ANSWERS-researcher collects data about different social groups (eg working-class; middle-class and upper-class) and then compares one group with another to identify what is evident in one group but not another

Which term refers to closed status positions that hinder social mobility? A) Class systems B) Caste systems C) Economic systems D) Financial systems - CORRECT ANSWERS-B) Caste systems The correct answer is B. Caste systems describe closed stratification systems that do not allow for social mobility. 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. - CORRECT ANSWERS-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 - CORRECT ANSWERS-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.

In determining which reactant loses the -OH group, which of the following isotopic substitutions would be most useful? A) Replace the acidic H of acetic acid with D B) Replace the alcoholic H of ethanol with D. C) Replace the carbonyl oxygen of acetic acid with O-18. D) Replace the hydroxyl oxygen of ethanol with O-18. - CORRECT ANSWERS- D) Replace the hydroxyl oxygen of ethanol with O-18. The answer to this question is D because this experiment involves labeling a group which does not exchange with other groups present prior to reaction and will therefore give information about the true identity of the groups, which are exchanged during the reaction. A person whose eye has a lens-to-retina distance of 2.0 cm, can only clearly see objects that are closer than 1.0 m away. What is the strength S of the person's eye lens? (Note: Use the thin lens formula 1/O + 1/I = S) A) -50 D B) -10 D C) 51 D D) 55 D - CORRECT ANSWERS-C) 51 D The answer to this question is C because the strength of the eye lens is equal to the inverse of the focal length of the eye lens. Its numerical value is given by (1 m)-1+(0.02 m)-1=1 D+50 D=51 D. Which statement correctly describes how enzymes affect chemical reactions? Stabilization of: A) the substrate changes the free energy of the reaction. B) the transition state changes the free energy of the reaction. C) the substrate changes the activation energy of the reaction. D) the transition state changes the activation energy of the reaction. - CORRECT ANSWERS-D) the transition state changes the activation energy of the reaction. The answer is D because the stabilization of the transition state, not the substrate, provides binding energy that is used to lower the activation energy. Which of the following will decrease the percentage ionization of 1.0 M acetic acid, CH3CO2H(aq)?* A) Chlorinating the CH3 group B) Diluting the solution

C) Adding concentrated HCl (aq) D) Adding a drop of basic indicator - CORRECT ANSWERS-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 - CORRECT ANSWERS-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 - CORRECT ANSWERS-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 - CORRECT ANSWERS-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

Compared to micellular Compound 1, Compound 2 is structurally more rigid as a result of what type of interaction? A) Intermolecular hydrogen bonding B) Intermolecular covalent bonding C) Intramolecular hydrogen bonding D) Intramolecular covalent bonding - CORRECT ANSWERS-B) Intermolecular covalent bonding The answer to this question is B. It can be reasoned that the interaction described is intermolecular in nature, since multiple molecules of micellular Compound 1 come together to form Compound 2, which is a solid. Multiple pieces of information point to the fact that the interaction is disulfide bond formation, including the fact that an oxidant causes the formation of Compound 2, which can be reversed by the addition of a reducing agent. Which amino acid residues were incorporated into Compound 1 to promote the adhesion of cells on the scaffold surfaces? A) Arg and Gly B) Cys and Gly C) Cys and Asp D) Asp and Arg - CORRECT ANSWERS-D) Asp and Arg The answer to this question is D. The residues that were engineered into the peptide for cell adhesion are arginine and aspartate as can be reasoned based on the structure of the peptide provided, and the description of the roles of the various residues provided in the passage. Which amino acid was incorporated into Compound 1 as a future site of covalent attachment to HA prior to mineralization? A) Ser B) Ala C) Tyr D) Thr - CORRECT ANSWERS-A) Ser The answer to this question is A because serine is the residue that was phosphorylated, and phosphorylation enabled the protein to be subsequently attached to hydroxyapatite (HA). Compound 1 was designed to exhibit pH-dependent self-assembly. What feature(s) of the molecule is(are) responsible for the pH dependence of aggregation (Equation 1)? A) Thiol side chains that can hydrogen bond B) Long alkyl chains that exhibit predominantly London forces C) Side chains whose net charge responds to pH

D) Covalent linkages that reversibly hydrolyze - CORRECT ANSWERS-C) Side chains whose net charge responds to pH 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. - CORRECT ANSWERS-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 - CORRECT ANSWERS-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. - CORRECT ANSWERS-C) Individual molecular volume and intermolecular forces are negligible.

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 - CORRECT ANSWERS-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 a system is trigonal planar and the hybridization scheme that facilitates this geometry is sp2. Which reaction is catalyzed by LipA? A) ATP hydrolysis B) Peptide bond cleavage C) Hydrolysis of triacylglycerides D) Transfer of carboxyl groups - CORRECT ANSWERS-C) Hydrolysis of triacylglycerides The answer is C because the fact that LipA is a lipase, which means it must hydrolyze fatty acids. Compared to the wild-type LipA, what is the change in net charge in variant XI at pH 7? R33G K112D M134D Y139C I157M A) + B) + C) - D) -4 - CORRECT ANSWERS-D) - The answer is D because the amino acid substitutions replace amino acids with charges of +1, +1, 0, 0, and 0 with ones that have charges of 0, −1, −1, 0, and 0 so the net charge goes from +2 to −2. The data in Figure 1 show that: A) the unfolding of LipA proteins is a non-reversible process. B) exposure to high temperature eliminates any variant protein activity. C) variation in the flexible regions of LipA decreases the temperature sensitivity of activity.

D) wild-type LipA loses all activity when first heated to 50°C. - CORRECT ANSWERS-C) variation in the flexible regions of LipA decreases the temperature sensitivity of activity. The answer is C because the data show that variation of the flexible regions results in less temperature sensitivity of activity. Activity returns even when variants are exposed to high temperature. By what factor is the proton concentration increased in the experiments shown in Figure 1B from those shown in Figure 1A? Figure 1A - pH 7 Figure 1B - pH 4 A) 2 B) 10 C) 200 D) 1000 - CORRECT ANSWERS-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 - CORRECT ANSWERS-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 - CORRECT ANSWERS-C) Ribose The answer is C because UDP contains uridine, which is a nucleic acid used in RNA. The structure of RNA contains ribose.

B) Phosphodiester C) a-1,4-glycosidic bond D) a-1,6-glycosidic bond - CORRECT ANSWERS-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− D) H3PO4 + H2O → H3O+ + H2PO4− - CORRECT ANSWERS-B) HPO42− + H2O → H3O+ + PO43− The answer to this question is B. HPO42− has a high negative charge and so dissociation of it will occur to the least extent. Gamma decay occurs when a nucleus emits: A) a photon B) a proton C) a neutron D) an electron - CORRECT ANSWERS-A) a photon The answer to this question is A because, by definition, gamma decay means the emission of photons by the nucleus. When a 0.1 M H2SO4 solution is added to pulverized blackboard chalk, the following reaction takes place. CaCO3(s) + H2SO4(aq) --> CaSO4(s) + CO2(g) + H2O(l) At 25°C, the reaction is spontaneous and has: A) negative ΔG° and positive ΔS°. B) negative ΔG° and negative ΔS°. C) positive ΔG° and negative ΔS°. D) positive ΔG° and positive ΔS°. - CORRECT ANSWERS-A) negative ΔG° and positive ΔS°. The answer to this question is A because spontaneous reactions must have a negative ΔG°, and reaction that create gaseous products from solids and liquids must have a positive ΔS°.

Which of the following diagrams does NOT illustrate a function of an automobile catalyst converter? "The catalyst aids in the conversions of carbon monoxide to carbon dioxide, hydrocarbons to carbon dioxide and water, and nitric oxide to nitrogen gas. Unfortunately, catalytic converters also can catalyze the oxidation of SO2 to SO3, which subsequently reacts with moisture to form unwanted sulfuric acid." A) CH4 --> CO2 + H2O B) CO --> CO C) SO3 --> SO2 + H2O D) NO --> N2 - CORRECT ANSWERS-C) SO3 --> SO2 + H2O The answer to this question is C because this response depicts a chemical transformation that is NOT catalyzed by an automobile's catalytic converter. 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. - CORRECT ANSWERS-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. - CORRECT ANSWERS-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.

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. - CORRECT ANSWERS-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 - CORRECT ANSWERS-D) 4.0 A The answer to this question is D because according to Ohm's law, current is equal to voltage divided by resistance, hence 2.0 V/0.5 Ω = 4.0 A. The equilibrium BaCrO4(s) --> Ba2+(aq) + CrO42-(aq) exists in a saturated aqueous solution of BaCrO4. Dissolution of Na2CrO4 in a saturated aqueous BaCrO4 solution would: A) have no effect on the position of this equilibrium B) shift this equilibrium left C) shift this equilibrium right D) shift this equilibrium first right and then left - CORRECT ANSWERS-B) shift this equilibrium left The answer to this question is B because dissolution of Na2CrO4 would introduce the common ion, CrO42-, which would reduce the solubility of BaCrO4 due to the common ion effect. What volume of a 0.120 M CaI2 solution would contain 0.078 mol of the solute? A) 35.0 mL

B) 65.0 mL C) 350 mL D) 650 mL - CORRECT ANSWERS-D) 650 mL The answer to this question is D. In order to obtain the volume of solution necessary to provide a given amount of solute in moles, one needs to take the number of moles and divide by the solution concentration in molarity. Which measurement unit CANNOT be used to express power? A) kg x m^2 x s^ B) J x s^- C) ft x lb x s^- D) W - CORRECT ANSWERS-A) kg x m^2 x s^ The answer to this question is A because the measurement unit of power is watt, defined as J/s = ft•lb/s = kg•m2/s3. CARS: Consider that some groups are defined as "cults"; members of these extremist sects generally live communally and obey an authoritarian, charismatic leader. Assume that all cults have fewer than 100 members. This information would tend to weaken the passage's assertions about the: A) ability of great orators to sway large groups B) loss of personality and sense of responsibility C) difficulties involved in convening large assemblies D) reasonableness of small groups compared to large groups - CORRECT ANSWERS-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 - CORRECT ANSWERS-A) the poet is no longer able to challenge the public's response to the poet's life and work

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. - CORRECT ANSWERS-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. - CORRECT ANSWERS-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 regardless of teaching techniques, then this would clearly weaken the author's explanation for the effects of class-size reductions. CARS: Which of the following underlying assumptions about professors is implied by the passage argument? A) Most of them are generalists, not specialists B) Most of them lack a preference for particular geographic areas. C) Most of them care more about ideas than they do about actual places. D) Most of them in the US attended college or graduate school outside their home states. - CORRECT ANSWERS-C) Most of them care more about ideas than they do about actual places. he author says that rootless professors (deemed to be most professors) "are ignorant of the values of connectedness to place" (paragraph 2), that they

should include local content rather than "abstract theories about distant peoples" in their courses (paragraph 4), and that "what is needed is... educators willing to take root and cultivate a sense of place" (paragraph 6). All of these suggest that professors care more about ideas than they do about actual places. C is correct. CARS: The author would most likely favor a college course that: A) emphasized hands-on experience in a laboratory over textbook learning B) crossed disciplines and combined creative arts with science C) applied classroom concepts to a community garden project D) required a semester of studying and living in another country - CORRECT ANSWERS-C) applied classroom concepts to a community garden project The answer is C, because the passage is an argument for grounding university education in a more "particular," place-based ethos. The author contends that professors "should include local content in their courses." Option C emphasizes participation in a local setting, exemplifies the environmental awareness the author advocates in the last paragraph, and fulfills the author's prescription of "transforming the world immediately outside the classroom into a laboratory" (paragraph 4). CARS: The passage discussion of local content (paragraph 5) assumes which of the following? A) Students lack the ability to criticize "concrete realizations about observable communities". B) Materials that deal with social sciences should not be part of a rooted education. C) There is an "artificial boundary between the roles of student and citizen". D) Professors have traveled to distant communities more often than have the students they teach. - CORRECT ANSWERS-The answer is C. In paragraph 5, the author advocates a locally-based curriculum that is meant to allow students to do more than study "abstract theories [and]... airy generalizations. The author writes that this "rooted education... will tend to erase the artificial boundary between the roles of student and citizen." Because the 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.