AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255, Exams of Nursing

Download AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 and more Exams Nursing in PDF only on Docsity! AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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) 0.20 B) 0.50 C) 5 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) D) there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of 1-pentanol. - Correct Answer ✅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 - Correct Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) attraction. This substance will therefore migrate the fastest and be the first peak in the gas chromatograph (gc) trace. R vs. S stereochemistry* - Correct Answer ✅R = clockwise C = counter-clockwise Acetic acid and ethanol react to form an ester product as shown below. 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 Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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: AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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) 0.7 B) 1.4 C) 2.1 D) 3.0 - Correct Answer ✅B) 1.4 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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) C) polarization of photons emitted D) number of photons emitted - Correct Answer ✅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 - Correct Answer ✅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. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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% - Correct Answer ✅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? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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 Answer ✅C) The total cross-sectional area of capillaries exceeds that of arteries. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) A1v1 = A2v2 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) sp3 C) p D) d2 sp3 - Correct Answer ✅D) d2 sp3 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. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 - Correct Answer ✅C) ATP The answer is C because the requirement of ATP for kinase activity implies the phosphate groups come from ATP. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) What are the hybridization states of the carbon atoms involved in the conversion of trans to cis retinal? A) sp B) sp2 C) sp3 D) sp3d - Correct Answer ✅B) sp2 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 Answer ✅C) Hydrolysis of triacylglycerides AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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) +4 B) +3 C) -3 D) -4 - Correct Answer ✅D) -4 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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: AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) "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. - Correct Answer ✅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? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) "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 - Correct Answer ✅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? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) SO3, which subsequently reacts with moisture to form unwanted sulfuric acid." A) CH4 --> CO2 + H2O B) CO --> CO2 C) SO3 --> SO2 + H2O D) NO --> N2 - Correct Answer ✅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 Answer ✅B) The products will be contaminated. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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. - Correct Answer ✅D) Yes; E°cell = +0.466. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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. - Correct Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) D) free political choice from free economic consumption - Correct Answer ✅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. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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 Answer ✅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. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) 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. - Correct Answer ✅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). AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) D) one or more audience members became possessed - Correct Answer ✅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 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) C) I and II only D) II and III only - Correct Answer ✅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% AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) D) 100% - Correct Answer ✅A) 0% The answer to this question is A. According to the passage, HSP110ΔE9 transcripts are not present in noncancerous tissue of people with MSI CRC. This means that the deletion mutation in the HSP110 T17 microsatellite is a somatic, not germ line, mutation. Therefore, the mutation will not be inherited, and the percent chance that the child of a person with this mutation will inherit it is 0%. Which nucleotide pairing(s) would be recognized by the MMR system during DNA replication? I. dTMP and dCMP II. dGMP and dAMP III. dAMP and dTMP A) I only B) III only C) I and II only AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) The answer is A because phenylalanine is a neutral amino acid just like tryptophan and shares an aromatic structure. This means it is most likely to be recognized by the same transport machinery. Based on the information in the passage, a mature AT1 mRNA is most likely to contain a sequence coding for which genetic factor(s)? A) Signal sequence B) Introns C) Promoter D) Nuclear localization signal - Correct Answer ✅A) Signal sequence The answer to this question is A. The passage indicates that AT1 is a transmembrane protein. Transmembrane proteins enter the endomembrane system by docking at the rough ER. This is facilitated by using a signal sequence. Mature mRNAs are not likely to contain introns (B) or promoter sequences (C). A nuclear localization signal permits proteins to enter the nucleus. This is not likely for a transmembrane protein (D). AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) Pellagra also results from a deficiency of nicotinamide, which is synthesized from tryptophan. Nicotinamide nucleotides are neither oxidized nor reduced during which step of cellular respiration? A) Glycolysis B) Chemiosmosis C) Citric acid cycle D) Electron transport chain - Correct Answer ✅B) Chemiosmosis The answer is B because NAD+ is the oxidized form, and NADH is the reduced form of nicotinamide adenine dinucleotide. NAD+ is neither reduced to form NADH, nor is NADH oxidized to form NAD+ specifically during chemiosmosis. If a man with a mutant copy of Ace2 has a child with a woman that is heterozygous for the mutant Ace2 allele, what is the probability that the child will be a female and homozygous for the mutant Ace2 allele? "loss-of-function mutations in the X-linked Ace2 gene" AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) A) 0 B) 0.25 C) 0.75 D) 1 - Correct Answer ✅B) 0.25 The answer to this question is B because a cross between an affected male and an unaffected female carrier will produce an affected female approximately 25% of the time. During the initiation of muscle contraction, mysosin binds actin after troponin binds to which ion? A) H+ B) K+ C) Na+ D) Ca2+ - Correct Answer ✅D) Ca2+ The answer to this question is D because during the initiation of muscle contraction, free Ca2+ in the cytosol binds to troponin, which pulls AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) D) Medullary portion of the collecting duct - Correct Answer ✅D) Medullary portion of the collecting duct The answer is D because glomerular filtrate is most concentrated in the medullary portion of the collecting duct, compared to the other kidney structures listed. What aspect of Experiment 1 does NOT address whether membrane composition has an effect on Na+K+ ATPase activity? The activity of the Na+K+ ATPase: A) showed less temperature dependence in the 14:1 liposome than the 14:0 liposome B) was highest in the 14:0 liposomes at all temperatures C) increased with temperature in both the 14:1 liposome and the 14:0 liposome D) was greater at all temperatures when cholesterol was present - Correct Answer ✅C) increased with temperature in both the 14:1 liposome and the 14:0 liposome AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) The answer is C because the researchers were not trying to show that protein activity increases with temperature, which is an expected result of all kinetic studies assuming the protein does not thermally denature. Which approach does NOT measure the activity of the Na+K+ ATPase? A) Measuring the rate of ATP hydrolysis B) Measuring the free energy of the ion transport C) Measuring the rate of ADP production D) Measuring the change in ion concentration within the liposome - Correct Answer ✅B) Measuring the free energy of the ion transport The answer to this question is B because free energy is a thermodynamic quantity and is NOT a kinetic property. Activity is a kinetic property. What is the function of the Na+K+ ATPase during a neuronal action potential? A) Stimulation of the action potential B) Depolarization of the membrane AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) C) Hyperpolarization of the membrane D) Restoration of the resting potential - Correct Answer ✅D) Restoration of the resting potential The answer is D because the Na+K+ ATPase functions to restore the resting membrane potential by moving the ions against their concentration gradients. In which direction does the Na+K+ ATPase transport ions across the cell membrane upon ATP hydrolysis? A) Na+ is transported out of the cell; K+ is transported into the cell. B) Na+ is transported into the cell; K+ is transported out of the cell. C) Both Na+ and K+ are transported into the cell. D) Both Na+ and K+ are transported out of the cell. - Correct Answer ✅A) Na+ is transported out of the cell; K+ is transported into the cell. The answer is A because the Na+K+ ATPase transports 3 sodium ions out of the cell and 2 potassium ions into the cell with each ATP hydrolyzed. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) D) They bind to STN in the cytoplasm - Correct Answer ✅B) They contain a p65/cRel binding site in their promoter region The answer is B because the constantly active signaling pathway will result in the overexpression of genes that are under control of the p65/cRel transcription factors. Mitochondrial disruption would occur if the apoptotic machinery was stimulated, but these genes are antiapoptotic. Mutations occur to the NF-kB pathway, which cause the constant activation. The gene products of this signaling pathway do not necessarily have mutations, as their overexpression is sufficient for pathogenesis. Binding to STN is not discussed. Which mechanism best describes how P-gp facilitates drug resistance? "P-gp is a plasma membrane ABC transporter that has broad substrate specificity for hydrophobic compounds." A) P-gp binds to antitumor drugs in the presence of ATP and degrades the drugs. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) B) P-gp serves as a pump and uses active transport to move antitumor drugs outside the cell. C) P-gp prevents the entry of anti-tumor drugs into the cell. D) P-gp causes increased membrane permeability, which causes antitumor drugs to exit the cell. - Correct Answer ✅B) P-gp serves as a pump and uses active transport to move antitumor drugs outside the cell. The answer is B because P-gp is an ABC transporter protein, which uses ATP to actively transport antitumor drugs out of the cell. The formation of which reaction products is increased in MBCD-treated MDR cells after exposure to 100 µM cholesterol? "ATPase activity" A) AMP + ADP B) ADP + Pi C) ATP + Pi D) ADP + ATP - Correct Answer ✅B) ADP + Pi AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) The answer is B because at 100 µM cholesterol in the depleted MDR cells, ATPase activity, which is ATP hydrolysis activity, is completely restored. ATP hydrolysis produces ADP and inorganic phosphate. What is the most likely location of P-gp within the plasma membrane? "It has been shown that P-gp exhibits AtPase activity and is localized in cholesterol-rich domains within the membrane" A) Associated with lipids on the cytoplasmic side only B) Associated with lipids on the extracellular side only C) Peripheral to the plasma membrane D) Within a lipid raft - Correct Answer ✅D) Within a lipid raft The answer D because the passage states the P-gp is found in cholesterol rich domains, which would indicate lipid rafts. MBCD is composed of which type of molecule? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) The answer to this question is A because the initial filtration in the glomerulus occurs as blood pressure forces the fluid from the glomerulus into the lumen of Bowman's capsule. Enzymes alter the rate of chemical reactions by all of the following methods EXCEPT: A) co-localizing substrates B) altering local pH C) altering substrate shape D) altering substrate primary structure - Correct Answer ✅D) altering substrate primary structure The primary structure of a protein substrate is the amino acid sequence of the protein. Enzymes cannot alter primary structures of protein, but can colocalize substrates, alter local pH, and alter substrate shape. Which of the following statements gives the most fundamental reason why ornithine is unlikely to be found in proteins synthesized in vivo? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) "Ornithine is an amino acid that is found in cells, but not incorporated into proteins." A) There is no codon for it in the standard genetic code. B) It cannot form a peptide bond. C) It is not available in the diet. D) It has a net positive charge in aqueous solution. - Correct Answer ✅A) There is no codon for it in the standard genetic code. The answer to this question is A, because without a corresponding codon in the genetic code, an amino acid cannot take part in the process of protein translation from an mRNA transcript. Which of the following terms best describes the role of ornithine decarboxylase in the reaction shown in Equation 1? A) Catalyst B) Cofactor C) Substrate D) Activator - Correct Answer ✅A) Catalyst AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) The answer is A because ornithine decarboxylase is an enzyme and enzymes are catalysts. The ornithine decarboxylase reaction has been studied extensively by biomedical researchers. The most likely reason for the interest of these researchers is that the reaction is: "In mammals and many other organisms, it can be converted to diaminobutane via the ornithine decarboxylase reaction, an early event in cell division." A) a good source of ornithine B) an early event in cell division C) unique to mammals D) one in which a chiral reactant is converted to an achiral product - Correct Answer ✅B) an early event in cell division AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) B) glycolysis C) electron transport D) oxidative phosphorylation - Correct Answer ✅A) the Krebs (citric acid) cycle The answer to this question is A, because acetyl coenzyme A is the main input of the citric acid cycle. The lung cells of heavy smokers would be expected to have greatly increased concentrations of cP-450 and: A) DNA sequences that code for cP-450. B) mRNA sequences that code for cP-450. C) rRNA that process cP-450. D) tRNA that are specific for cysteine. - Correct Answer ✅B) mRNA sequences that code for cP-450. The answer to this question is B, because protein levels relate most directly to mRNA levels. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) No drowsiness was initially felt by the alcoholic because the previous abuse of alcohol had: "cP-450 is inducible. That is, when an organism is challenged by a new toxin or by increased concentrations of a toxin, the organism can increase its concentration of cP-450 and thus metabolize and excrete the toxin more effectively." A) denatured the cP-450. B) inhibited the cP-450. C) reduced the cP-450. D) induced the cP-450. - Correct Answer ✅D) induced the cP-450. The answer to this question is D, because the passage states that cP-450 is inducible and thus previous abuse of alcohol, a cellular toxin, results in an increased concentration of cP-450. This leads to rapid barbiturate metabolism by cP-450 and the absence of initial drowsiness. The pericytes used in these experiments were probably in which phase of the cell cycle? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) "Pericytes, smooth-muscle cells, and fibroblasts were growth-arrested—that is, treated so that they would not divide but other metabolic processes would function normally." A) Telophase B) Metaphase C) Anaphase D) Interphase - Correct Answer ✅D) Interphase The question asks the examinee to identify the phase of the cell cycle in which the growth of the pericytes was arrested. According to the passage, the pericytes were treated so that they would not divide but would, from a metabolic perspective, continue to function normally. Three of the listed options (A, B, and C) are phases of mitosis and thus, occur during cell division. Interphase (D) is the phase of the cell cycle between cell divisions and is the phase in which the cell obtains nutrients, grows, reads its DNA, and conducts other "normal" cell functions. Thus, D is the best answer. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) The question asks the examinee to use the information in the passage and in Figure 1 to determine what cells are most important in the exchange of oxygen between the blood and the surrounding tissues. An examination of Figure 1 shows that endothelial cells separate the blood from the surrounding tissue. Thus, B is the best answer. The process of culturing bacteria often involves inoculation of cells on a noncellular, agar-based medium. Such a methodology would NOT result in growth of animal viruses because animal viruses: A) are obligate parasites B) lack DNA C) assimilate carbon D) require essential vitamin supplements for growth - Correct Answer ✅A) are obligate parasites The answer is A because viruses can only reproduce in a host cell, and are therefore obligate intracellular parasites. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) In general, telomeres are NOT important to bacterial cells because most bacterial chromosomes: A) do not replicate B) are circular. C) replicate quickly and efficiently. D) are composed of single-stranded DNA - Correct Answer ✅B) are circular. The answer to this question is B because in most prokaryotes, DNA is circular and therefore does not have the repetitive, non-coding nucleotide sequences called telomeres that occur in eukaryotic DNA. Which of the following best describes the bond that would form between the following two nucleotides if they were located adjacent to each other as shown in a single strand of DNA? 5' thymine & 3' adenine A) A bond between the phosphate of the thymine and the phosphate of the adenine AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) B) A bond between an oxygen in the thymine base and a nitrogen in the adenine base C) A bond between the phosphate of the thymine and the sugar of the adenine D) A bond between the phosphate of the adenine and the sugar of the thymine - Correct Answer ✅D) A bond between the phosphate of the adenine and the sugar of the thymine The answer to this question is D because nucleotides are linked to one another by phosphodiester bonds between the sugar base of one nucleotide and the phosphate group of the adjacent nucleotide in a way that the 5' end bears a phosphate, and the 3' end a hydroxyl group. During an action potential, the movement of sodium ions into a neuron causes the neuronal membrane to do which of the following? A) Inactivate B) Hyperpolarize C) Repolarize D) Depolarize - Correct Answer ✅D) Depolarize AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) If a patient with Addison's disease is given too high a replacement dose of glucocorticoids, the effect over time will be an increase in: A) muscle mass B) muscle weakness C) red blood cell count D) heart rate - Correct Answer ✅B) muscle weakness The answer to this question is B because glucocorticoids act on skeletal muscle causing the breakdown of muscle proteins. Therefore, if a patient is given too high a replacement dose of glucocorticoids, this will result in muscle weakness. The most rapid rate of gluconeogenesis will most likely occur in the body when: A) blood glucose levels are high B) cortisol release is inhibited C) the body's stores of carbohydrates are low AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) D) the body's stores of proteins are low - Correct Answer ✅C) the body's stores of carbohydrates are low The answer to this question is C, because gluconeogenesis is the pathway for the synthesis of glucose from other metabolic compounds and thus it is activated when the body's stores of carbohydrates are low. Glucose transporter proteins in the liver do not require the presence of insulin to facilitate the uptake of glucose. However, insulin does stimulate the first step in the glycolytic pathway within the liver. Therefore, in liver cells, insulin most likely: A) hinders glucose uptake by increasing the cellular concentration of glucose. B) aids glucose uptake by decreasing the cellular concentration of glucose. C) hinders glucose uptake by using the ATP needed by the glucose transporter proteins. D) aids glucose uptake by providing the ATP needed by the glucose transporter proteins. - Correct Answer ✅B) aids glucose uptake by decreasing the cellular concentration of glucose. AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) The answer to this question is B because the stem states that insulin stimulates the first step in the glycolytic pathway in the liver, thus decreasing the cellular concentration of glucose. This results in increased uptake of glucose to maintain the cellular concentration of glucose. Exercise promotes the insulin-independent uptake of glucose in working skeletal muscles. Given this, regular exercise would most likely reduce blood glucose levels in patients with which type(s) of diabetes? "There are two main types of diabetes. Many cases of Type 1 diabetes, in which the body is unable to produce insulin, are caused by an autoimmune response directed against pancreatic β cells. While the body often produces normal-to-elevated amounts of insulin in Type 2 diabetes, its ability to respond to insulin is compromised." A) Type 1 only B) Type 2 only C) Both Type 1 and Type 2 D) Neither Type 1 nor Type 2 - Correct Answer ✅C) Both Type 1 and Type 2 AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) B) 5.4 fg and 5.45 fg C) 5.4 fg and 5.5 fg D) 5.45 fg only - Correct Answer ✅B) 5.4 fg and 5.45 f The answer to this question is B because DNA replication is semi- conservative. Therefore, after the first round of cell division the genome mass in each bacterium will be 5.45 fg (one DNA strand will contain 15N and the other strand 14N). Following the second round of cell division, half of the bacteria will have a genome mass of 5.4 fg (14N exclusively) and the other half a mass genome of 5.45 fg (14N in one DNA strand and 15N in the other). Correct Correct Answer Your answer A B C D✓ Time Spent: 2 mins 34 secs AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) Content & Skills CC1CFC1BIOSIRS2 Assume that K and M are two unlinked genes that affect hearing. The dominant K allele is necessary for hearing, and the dominant M allele causes deafness regardless of the other genes present. Given this, what fraction of the offspring of parents with the genotypes KkMm and Kkmm will most likely be deaf? A) 1/4 B) 3/8 C) 1/2 D) 5/8 - Correct Answer ✅D) 5/8 The answer to this question is D, because among the offspring of KkMm and Kkmm parents, the ones who lack a dominant K allele (necessary for hearing), or carry a dominant M allele (causes deafness) are deaf. Based on the Punnett square analysis, 10 out of 16 or 5/8 of all offspring are likely to be deaf. An RNA molecule has 1500 bases. What is the maximum number of amino acids it can encode? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) A) 500 B) 1000 C) 1500 D) 4500 - Correct Answer ✅A) 500 The answer to this question is A because each amino acid is encoded by three bases, so 1500/3 is 500, which is the maximum of amino acids the RNA molecule can encode. Compared to the simultaneous condition, the serial condition of the experiment would be more likely to cause: A) a primacy effect B) a state dependency effect C) a misinformation effect D) a dual-coding effect - Correct Answer ✅A) a primacy effect The answer to this question is A because, in the serial condition, the objects are presented to the participants one at a time, which might result in better memory for events at the beginning of the series (a primacy effect). AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) B) is influenced by categorical knowledge C) becomes more accurate with age D) relies solely on recall of distances - Correct Answer ✅B) is influenced by categorical knowledge The answer to this question is B because the nine-year-olds performed differently from adults, suggesting that spatial memory keeps undergoing changes after nine years of age. Because this categorical bias was present in adults, spatial memory does not necessarily become more accurate with age. Because world knowledge about categories affects people's judgments of distance, it is not accurate to say that spatial memory relies solely on the recall of distances. The children from the experiment in the passage participate in a separate study using Piaget's water conservation task. They are shown two identical beakers, containing equal amounts of water. The water from one of the containers is poured into a thinner and taller beaker. Which prediction is most likely to be confirmed? "7, 9, and 11-year old children and a group of adults were recruited to participate in a study of categorical bias" AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) A) All three age groups will state that the water in the taller beaker is greater in quantity B) The majority of the 11 year-olds will state that the amount of water in the taller beaker is the same as in the original beaker. C) The majority of the 9 and 11-year olds will state that the amount of water in the taller beaker is greater in quantity. D) The majority of the 7 year-olds will state that the amount of water in the taller beaker is the same as in the original beaker. - Correct Answer ✅B) The majority of the 11 year-olds will state that the amount of water in the taller beaker is the same as in the original beaker. The answer to this question is B because, according to Piaget's theory of cognitive development, conservation tasks are mastered during the concrete operations stage, which starts at approximately 7 years and ends around 11 to 12 years. The majority of the 11-year-olds will have completed this stage, which will allow them to judge that pouring water into a taller beaker does not change its quantity. Maintenance Factor 1 is most closely related to which approach to psychological disorders? AAMC MCAT Practice Exam 1 Questions and Answers (Latest Update 2023) Verified Answers (255 Questions) "Specifically, patients with high interoceptive awareness are likely to associate mild changes in bodily sensations (such as slightly heightened heartbeat) with the panic they experienced during panic attacks; this leads to conditioned fear in response to changes in bodily sensations (Maintenance Factor 1)" A) Psychodynamic B) Behaviorist C) Trait D) Humanistic - Correct Answer ✅B) Behaviorist The answer to this question is B because Maintenance Factor 1 focuses on the role of classical conditioning, which is most closely related to the behaviorist approach. psychodynamic approach - Correct Answer ✅includes all theories in psychology that see human functioning based upon the interaction of drives and forces within the person, particularly unconscious, and between the different structures of the personality