MCAT AAMC Practice Exam 3

Which two classes of enzymes are needed in the two-step conversion of cytosine to 5hmC? A. Transferase and oxidoreductase B. Hydrolase and ligase C. Oxidoreductase and hydrolase D. Transferase and ligase

A. This is a Biochemistry question that falls under the content category "Principles of chemical thermodynamics and kinetics." The answer to this question is A because the first step involves transfer of a methyl group to cytosine, and the next step involves the hydroxylation of that methyl group. Therefore, the two classes of enzymes needed are a transferase and an oxidoreductase. It is a Knowledge of Scientific Concepts and Principles question because its solution requires recalling the definitions and names of enzyme classifications.

Within the intestines, unabsorbed fats are broken down into fatty acids by intestinal bacteria. Given this, excess unabsorbed fats most likely have which of the following effects within the intestines? A. They increase the osmotic pressure within the intestines, leading to diarrhea. B. They decrease the osmotic pressure within the intestines, leading to diarrhea. C. They increase the osmotic pressure within the intestines, leading to constipation. D. They decrease the osmotic pressure within the intestines, leading to constipation.

A. This is a Biology question that falls under the content category "Structure and integrative functions of the main organ systems." The answer to this question is A because an excess of unabsorbed fats in the intestines inhibits normal water and electrolyte absorption, resulting in increased osmotic pressure and diarrhea. It is a Reasoning about the Design and Execution of Research question because it requires establishing causal relationships between variables.

Certain viruses contain RNA as their genetic material. One of the ways these RNA viruses replicate themselves is to: A. code for or carry a transcriptase that copies viral RNA. B. infect microorganisms possessing RNA as their genetic material. C. alter the host cell's polymerase in order to synthesize progeny viral RNA from the viral RNA template. D. stimulate the transcription of specific sequences of the host's DNA, which, in turn, direct the assembly of viral particles.

A. This is a Biology question that falls under the content category "The structure, growth, physiology, and genetics of prokaryotes and viruses." The answer to this question is A because RNA viruses require a type of transcriptase (reverse transcriptase) to replicate themselves. It is a Scientific Reasoning and Problem Solving question because it requires determining which mechanism is most reasonable for the replication of RNA viruses.

Which statement best accounts for the hereditary transmission of SDH-linked paraganglioma in a parent specific manner? SDH is: A. an imprinted gene. B. a Y-linked gene. C. an X-linked gene. D. a tumor suppressor gene.

A. This is a Biology question that falls under the content category "Transmission of genetic information from the gene to the protein." The answer to this question is A because imprinted genes are expressed in a parent-specific manner. B is incorrect because based on the passage both sexes may carry the mutated allele. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of regulation of gene expression.

Which of the following animal pairs best illustrates the outcome of convergent evolution? A. The dolphin and the shark B. The domestic sheep and the mountain goat C. The polar bear and the panda bear D. The light-colored and the dark-colored forms of the peppered moth

A. This is a Biology question that falls under the content category "Transmission of heritable information from generation to generation and the processes that increase genetic diversity." The answer to this question is A because convergent evolution is defined as a process whereby distantly related organisms independently evolve similar traits to adapt to similar needs. It is a Scientific Reasoning and Problem Solving question because it requires scientific evaluation of various animal traits in relation to convergent evolution.

The average osmotic pressure of ocean water is 28 atm corresponding to a concentration of 0.50 M solutes (approximated as NaCl). What is the approximate concentration of solutes (also approximated as NaCl) present in blood with an osmotic pressure of 7 atm? A. 0.12 M B. 0.25 M C. 2.0 M D. 3.5 M

A. This is a General Chemistry question that falls under the content category "Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms." The answer to this question is A because osmotic pressure is directly proportional to solute concentration. Since the osmotic pressure of blood is one-fourth that of ocean water, the solute concentration is also one-fourth that of ocean water, or 0.25 × 0.50 M = 0.12 M. It is a Scientific Reasoning and Problem Solving question because it requires working with scientific models to solve a problem.

In its lowest-energy electron configuration, zinc has a: A. filled 3d energy level and a filled 4s energy level. B. half-filled 3d energy level and a filled 4s energy level. C. filled 3d energy level and a half-filled 4s energy level. D. half-filled 3d energy level and a half-filled 4s energy level.

A. This is a General Chemistry question that falls under the content category "Atoms, nuclear decay, electronic structure, and atomic chemical behavior." The answer to this question is A, based on subshell filling rules, the 12 valence electrons occupy 4s and 3d subshells, which are completely filled. Zn is element number 30 and in Group 12 of the Periodic Table. It is a Scientific Reasoning and Problem Solving question because you reason using scientific principles and models to draw a conclusion.

Which of the following molecules has an octahedral geometry? A. SF6 B. CBr4 C. XeF4 D. BrF3

A. This is a General Chemistry question that falls under the content category "Nature of molecules and intermolecular interactions." The answer to this question is A because SF6 is an AX6 system with no lone pairs As a result, SF6 will adopt an octahedral bonding arrangement to minimize the repulsive interactions of the bonding domain electrons. It is a Knowledge of Scientific Concepts and Principles question because you must recognize a correct scientific principle.

If the reaction shown in Equation 1 is spontaneous, the value of K must be: A. greater than 1. B. equal to ΔG. C. less than 1. D. equal to zero.

A. This is a General Chemistry question that falls under the content category "Principles of chemical thermodynamics and kinetics." The answer to this question is A, because a spontaneous reaction is one that exhibits ΔG < 0. Since ΔG = -RTln(Keq), this means that Keq must be > 1. It is a Knowledge of Scientific Concepts and Principles question because you must identify the relationship between the closely related concepts of free energy and equilibrium constant for a reaction.

Which of the following properties of a 2.3 MHz ultrasound wave remains unchanged as it passes into human tissues? A. Frequency B. Wave speed C. Amplitude D. Wavelength

A. This is a Physics question that falls under the content category "How light and sound interact with matter." The answer to this question is A because the frequency of a wave is not affected by the medium through which it propagates. It is a Knowledge of Scientific Concepts and Principles question because it asks you to use data to recognize correct scientific principles.

Based on the information presented in the passage, which correlation coefficient provides the best estimate of the association between SES and level of exposure to stress? A. -0.20 B. -0.05 C. +0.15 D. +0.50

A. This is a Psychology question that falls under the content category "Responding to the world." The answer to this question is A because the passage (last paragraph) implies a negative correlation between socioeconomic position and exposure to stress. The other negative correlation (B) can be ruled out, because it is very weak (and thus not likely to have the kind of disproportionate effect that is discussed in the passage). It is a Data-based and Statistical Reasoning question because the question involves understanding the relationship between the data described in the passage and the way those data may be described using a correlation coefficient. "Regardless of the relative effect of race, research has established that people in lower socioeconomic positions face disproportionate exposure to certain stressors. Such disproportionate exposure, especially when combined with weak stress mediators, can explain persistent mental and physical health disparities."

Radioactive tritium (3H) labeled guanine has been used to measure the rate of biochemical processes that involve its binding or incorporation. Given that water is the solvent for this type of experiment, what is the best site for tritium labeling? A. I B. II C. III D. IV

A. This is an Organic Chemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is A, because the best site for tritium labeling would not exchange the tritium ions for protons in water. All of the N−H sites (II−IV) would readily exchange tritium protons due to their lone pair-facilitating protonation and subsequent tritium exchange with water, but the C−H site (I), lacking a lone pair, would retain its tritium label. It is a Reasoning about the Design and Execution of Research question because the selection of the tritium-labeling site under aqueous conditions is essential to the experimental design.

What additional substance is necessary for Reaction 2 to take place? A. FAD B. NADH C. H2O D. Acetyl-CoA

A. This is a Biochemistry question that falls under the content category "Principles of chemical thermodynamics and kinetics." The answer to this question is A because an oxidizing agent is required for Reaction 2 to proceed. Of the choices listed, only FAD is a cofactor oxidant. It is a Knowledge of Scientific Concepts and Principles question because knowing the cofactors and their biochemical roles are fundamental biochemical concepts.

Based on the information in the passage, what is the most likely mechanism of inheritance for HPRCC? A. Autosomal dominant B. Autosomal recessive C. X-linked recessive D. Y linked

A. This is a Biology question that falls under the content category "Transmission of heritable information from generation to generation and the processes that increase genetic diversity." The answer to this question is A because the allele must be inherited in a autosomal dominant pattern in order for individuals II-1 and II-2 to produce both affected and unaffected offspring. The inheritance pattern for the offspring of these individuals is consistent with autosomal dominant if the parents are heterozygous. The rest of the pedigree is consistent with this mode of inheritance as well. In addition, the offspring of individuals II-1 and II-2 rule out autosomal recessive, X-linked recessive, and Y-linked. It is a Scientific Reasoning and Problem Solving question because in addition to interpreting the pedigree shown in the figure, it requires forming a hypothesis regarding the genetic transmission pattern of HPRCC. ----Does not skip generation. (recessive skip generations).

If certain stressors lead to an emotional response of anger and hostility, which consequence is more likely for individuals from lower socioeconomic positions? A. Increased incidence of heart disease B. Stronger reliance upon coping mechanisms C. Reduced external locus of control D. Fewer depressive symptoms

A. This is a Psychology question that falls under the content category "Responding to the world." The answer to this question is A because the stem states that certain stressors are related to anger and hostility, which have been found to be associated with increased risk of heart disease. It is a Scientific Reasoning and Problem Solving question because the question involves understanding a potential ramification of a study's findings.

If the NDU gene is amplified inside cells leading to overexpression of the protein, what event is likely to occur under hypoxic conditions? A. Oxygen consumption within the mitochondria will increase further. B. Oxygen consumption within the mitochondria will decrease further. C. Complex IV will further increase its activity. D. Complex IV will further decrease its activity.

B. This is a Biochemistry question that falls under the content category "Principles of bioenergetics and fuel molecule metabolism." The answer to this question is B because the data presented in Figure 3A indicate that compared to NDU-KO cells, in WT cells which possess NDU, oxygen consumption is reduced under hypoxia. Therefore, the overexpression of NDU is likely to further decrease oxygen consumption. It is a Scientific Reasoning and Problem Solving question because it requires reaching a conclusion based on the information presented in the passage.

Which of the following is LEAST likely to occur in a muscle fiber that is metabolizing anaerobically? A. Fermentation of glucose to lactic acid B. Phosphorylation of ADP within the electron transport chain C. Depletion of stores of glycogen D. Acidification of the cytoplasm

B. This is a Biochemistry question that falls under the content category "Principles of bioenergetics and fuel molecule metabolism." The answer to this question is B because the electron transport chain only provides ATP aerobically. Lack of oxygen effectively shuts down the Krebs cycle and the electron transport chain. It is a Knowledge of Scientific Concepts and Principles question because it requires recall of the basic scientific concept of anaerobic metabolism.

What are the effects of hypoxia on energy metabolism? In hypoxia: A. the citric acid cycle is induced to produce more NADH. B. lactic fermentation is induced to regenerate NAD+. C. the electron transport chain is induced to consume more NADH. D. glycogenesis is induced to regenerate NAD+.

B. This is a Biochemistry question that falls under the content category "Principles of bioenergetics and fuel molecule metabolism." The answer to this question is B because the passage states that in hypoxia, glycolysis is activated while mitochondrial functions (oxidative phosphorylation) are attenuated. This metabolic reprogramming leads to increased concentration of NADH inside the cell. For glycolysis to proceed, NADH must be converted back to NAD+ through lactic fermentation. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of the net molecular and energetic results of respiration processes.

Which component of the electron transport chain is defective in cells from an SDH-linked paraganglioma tumor? A. Complex I B. Complex II C. Complex III D. Complex IV

B. This is a Biochemistry question that falls under the content category "Principles of bioenergetics and fuel molecule metabolism." The answer to this question is B because the passage states that the paraganglioma tumor is associated with loss of function of succinate dehydrogenase, which is also known as Complex II, in the electron transport chain. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of enzymes involved in metabolic pathways.

The isoelectric focusing points pI for four proteins are shown in the following table. At which buffer pH would two out of four of the proteins adhere to a cation-exchange column? A. 3.0 B. 7.0 C. 9.5 D. 11

B. This is a Biochemistry question that falls under the content category "Separation and purification methods." The answer to this question is B because a cation-exchange column only binds to positively charged proteins, which only occurs when the pH is less than the pI. At pH 7.0, both proteins A and B would be positively charged. With distractors A, C, and D, there would be four, one, and zero positively charged proteins, respectively. It is a Reasoning about the Design and Execution of Research question because it inquires about the experimental conditions needed to achieve a desired result.

Which of the following is the most likely reason that 7 of the 9 clinically depressed patients with the R441H hTPH2 allele failed to respond to even the highest doses of SSRIs? These seven patients: A. also have a mutation in the postsynaptic serotonin receptor. B. do not release enough serotonin into the synapse for the SSRIs to make a difference. C. produce an enzyme that degrades the SSRIs before the SSRIs can have an effect. D. have a form of depression in which the postsynaptic serotonin receptors are constitutively activated.

B. This is a Biology question that falls under the content category "Structure and functions of the nervous and endocrine systems and ways in which these systems coordinate the organ systems." The answer to this question is B because based on the data shown in Figure 2, the R441H mutation results in drastically lower serotonin synthesis compared to a wild-type control. It is a Scientific Reasoning and Problem Solving question because it requires determining which mechanism blocks the effects of SSRI therapy.

The complement to the WT sequence does NOT contain which nucleoside? A. Deoxyadenosine B. Deoxycytidine C. Deoxyguanosine D. Deoxythymidine

B. This is a Biology question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is B because the WT sequence does not contain deoxyguanosine. The complementary sequence will therefore not include deoxycytidine. It is a Knowledge of Scientific Concepts and Principles question because you must recognize a correct scientific principle of nucleoside base-pairing. "The wild-type (WT) sequence was 5′-TTCCCTACCCTCCCCACCCTAA-3′, and the modified sequences had either a 5mC (5mC-WT) or a 5hmC (5hmC-WT) at position five."

HDACs change chromatin by: A. decreasing its coiling and promoting DNA replication. B. increasing its condensation and inhibiting transcription. C. decreasing charge repulsion between acetyl groups, which increases transcription. D. loosening the attachment of DNA to nucleosome core particles.

B. This is a Biology question that falls under the content category "Transmission of genetic information from the gene to the protein." The answer to this question is B because the passage states that HDACs counter the effects of histone acetyltransferases (HATs). As histone acetylation typically promotes transcription by modifying chromatin structure, HDACs would inhibit transcription by condensing chromatin structure. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of how transcription can be altered by histone and chromatin modification.

Consider the following data. Based on these data, HCO3- is best categorized as: A. a base since Ka > Kb for this ion. B. a base since Kb > Ka for this ion. C. an acid since Ka > Kb for this ion. D. an acid since Kb > Ka for this ion.

B. This is a General Chemistry question that falls under the content category "Unique nature of water and its solutions." The answer to this question is B because Kb for HCO3- is larger than Ka for this ion. The value of Kb is given as Kw/Ka for H2CO3. By comparing Ka to Kb, it is clear that amphoteric HCO3- is more basic than acidic in water. It is a Data-based and Statistical Reasoning question because you interpret data presented in a table to draw a conclusion.

What is the total mass of D-glucose dissolved in a 2-μL aliquot of the solution used for this experiment? A. 3.6 × 10-7 g B. 1.4 × 10-4 g C. 3.6 × 10-4 g D. 1.4 × 10-1 g

B. This is a General Chemistry question that falls under the content category "Unique nature of water and its solutions." The answer to this question is B. The stock solution consisted of 72 g of glucose in 1.0 L of solution (72 μg/μL). Therefore, 2 μL contains 144 μg, or 1.4 × 10-4 g of the solute. It is a Scientific Reasoning and Problem Solving question because you must determine and use a scientific formula to solve a problem. (I used Molarity equation .. Molarity=m/L and put 72 for M and 2 x 10^-6 for L)

Assume that in the study with the rat tissues, fluid flows at a speed of 0.30 mm/s through a typical capillary opening caused by a burst microbubble. Given this, which of the following is closest to the volume flow rate of fluid passing through the opening? A. 4.5 × 106 μm3/s B. 7.5 × 106 μm3/s C. 1.2 × 107 μm3/s D. 4.5 × 107 μm3/s

B. This is a Physics question that falls under the content category "Importance of fluids for the circulation of blood, gas movement, and gas exchange." The answer to this question is B because the volume flow rate is given by 2.5 × 104 µm2 × 0.30 mm/s = 7.5 × 106 µm3/s. It is a Scientific Reasoning and Problem Solving question because it asks you to determine and use scientific formulas to solve problems.

Every time a volunteer in a sleep study begins to exhibit rapid eye movements (REM), the experimenter wakes the person up. On the following night, when his or her sleep is uninterrupted, the person will most likely: A. have difficulty falling asleep. B. have more REM sleep than usual. C. have less REM sleep than usual. D. have the same sleep pattern as before the study.

B. This is a Psychology question that falls under the content category "Making sense of the environment." The answer to this question is B because after being REM-deprived the night before, the volunteer is going to exhibit "REM rebound." It is a Scientific Reasoning and Problem Solving question because the question involves making a prediction based on your understanding of phenomena related to sleep and the information provided in the question.

Which term is used to refer to the type of memory phenomenon examined in studies 1 and 2? A. Reproductive memory B. Flashbulb memory C. Prospective memory D. Eidetic memory

B. This is a Psychology question that falls under the content category "Making sense of the environment." The answer to this question is B because the subjectively vivid, compelling memories of details associated with reception of news about emotionally arousing events were referred to as flashbulb memories (Brown & Kulik, 1977). It is a Knowledge of Scientific Concepts and Principles question because the question involves the identification of a memory phenomenon that is illustrated by the example(s) provided. "Many participants' reports included details about where they were, what they were doing, who brought the news, how they and others felt, and what happened afterward."

Which hypothetical finding would pose the greatest challenge to the theory that race/ethnicity is socially constructed? A. During data collection for a large national survey, participants' self-chosen racial/ethnic category often differed from the racial/ethnic designation made by in-person interviewers. B. People who identified with one racial/ethnic group were found to have a significantly different genome than people who identified with another racial/ethnic group. C. During data collection for an experiment on facial recognition, participants failed to consistently identify the racial/ethnic category of people from other parts of the world. D. The medically evaluated health status of a representative sample of individuals from two different racial/ethnic groups was found to differ significantly between the groups.

B. This is a Sociology question that falls under the content category "Demographic characteristics and processes." The answer to this question is B because the social construction of race refers to the idea that there is little biological basis for race (or ethnicity). Instead, racial/ethnic categories mostly result from history, culture, and society. If a significant biological basis (specifically for this question, a genetic basis) to racial categories were discovered, however unlikely that might be, it would challenge the idea that race is socially constructed. The remaining options would not contest the social construction of race to the same degree. It is a Scientific Reasoning and Problem Solving question because the question involves evaluating which hypothetical evidence would provide the greatest challenge to a major theoretical principle.

Overexpression of which enzyme is likely to result in increased levels of HIF? A. Succinyl decarboxylase B. Succinyl-CoA synthetase C. Succinate dehydrogenase D. Succinate carboxylase

B. This is a Biochemistry question that falls under the content category "Principles of bioenergetics and fuel molecule metabolism." The answer to this question is B because the passage states that succinate modulates the level of HIF by inhibiting HIF hydroxylase, an enzyme that induces HIF degradation. Thus, overexpression of succinyl-CoA synthetase, which results in the increased production of succinate, will enhance HIF levels. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of enzymes and their products in metabolic pathways.

The pH of a 1 L phosphate buffer solution was measured as 7.6, but the experimental procedure calls for a pH 7.2 buffer. Which method will adjust the solution to the proper pH? (Note: The pKa values for phosphoric acid are 2.2, 7.2, and 12.3.) A. Add enough 1 M Na2HPO3 to increase the phosphate anion concentration ten-fold. B. Add 1 M NaOH to neutralize a portion of the hydronium ions found in the solution. C. Alter the ratio of monosodium/disodium phosphate added to favor the monosodium species. D. Add 100 mL distilled, deionized water to dilute the basicity of the buffer.

C. The pH of a 1 L phosphate buffer solution was measured as 7.6, but the experimental procedure calls for a pH 7.2 buffer. Which method will adjust the solution to the proper pH? (Note: The pKa values for phosphoric acid are 2.2, 7.2, and 12.3.)

Which statement is best supported by the data using the anti-AcTubK40 antibody? A. HDACs acetylate many types of target protein besides histones. B. βOHB is not a general deacetylase inhibitor. C. βOHB is present in the nucleus but not the cytoplasm. D. βOHB inhibits different deacetylases compared to butyrate.

B. This is a Biochemistry question that falls under the content category "Structure and function of proteins and their constituent amino acids." The answer to this question is B because according to Figure 1, βOHB has no significant effect upon tubulin deacetylase. A is incorrect because the data does not address this issue, since only one potential non-histone target is shown (tubulin). C is incorrect because βOHB was administered outside the cells, which means it must diffuse through both the plasma membrane and the cytoplasm to get into the nucleus and affect HDACs; therefore it is unlikely that βOHB is only in the nucleus. D is incorrect because there are no data presented indicating which HDACs butyrate acts on. Even though the activity of HDAC6 is not affected by βOHB, there are no data to confirm that butyrate regulates the activity of HDAC6. It is a Data-based and Statistical Reasoning question because it involves using the data presented in the figure to make a scientific conclusion.

If no braking occurs, a total of how much power would be required to keep the railcar moving at 40 m/s? A. 16 kW B. 40 kW C. 600 kW D. 800 kW

B. This is a Physics question that falls under the content category "Translational motion, forces, work, energy, and equilibrium in living systems." The answer to this question is B because the power required must match the work done by the friction force that tends to slow down the railcar, which is equal to the decelerating force multiplied by the constant speed, so 1000 N × 40 m/s = 40 kW. It is a Scientific Reasoning and Problem Solving question because it asks you to determine and use scientific formulas to solve problems. "The rolling friction of the wheels and the internal friction between the wheels and axles contribute a continuous 1000 N decelerating force any time that the railcar is in motion."

The researchers' decision to use individual (NOT group) therapy in each of the treatment sessions reduced the potential influence of: A. classical conditioning. B. observational learning. C. operant conditioning. D. elaboration likelihood.

B. This is a Psychology question that falls under the content category "Attitude and behavior change." The answer to this question is B because the design decision to conduct individual therapy sessions helped control for the extraneous influences of other patients, and observational learning is the only form of learning among the options that requires the presence of others. It is a Knowledge of Scientific Concepts and Principles question because the question involves the identification of a basic psychological phenomenon (observational learning).

The predictive models described in the final paragraph of the passage are most likely based on which assumption? A. Some psychosocial stressors will be perceived as out-group socialization. B. Exposure to some psychosocial stressors will be attributed to social identity. C. The health consequences of some behaviors will affect identity formation. D. The socioeconomic gradient in health will affect some minority groups.

B. This is a Sociology question that falls under the content category "Self-identity." The answer to this question is B because the passage describes the predictions of minority stress theoretical models, which suggest that the stressors of prejudice and discrimination will contribute to elevated levels of alcohol consumption among racial/ethnic minority group members. The question asks for an assumption that underlies this prediction. The link between prejudice, discrimination, and health rests, at least partly, on the assumption that individuals will attribute stressful experiences to their status as members of a racial/ethnic group (in other words, stressors will be linked to their social identity). It is a Scientific Reasoning and Problem Solving question because the question involves determining an assumption that underlies a prediction. "One area of research involves assessing the contribution of psychosocial stressors to AUDs. Some theoretical models predict that exposure to prejudice and discrimination will contribute to elevated levels of alcohol consumption among some racial and ethnic minority groups. However, patterns of use generally fail to support this prediction. For example, African Americans and Hispanic Americans have lower rates of alcohol consumption and AUDs than white Americans"

When two amino acids are joined via a peptide bond, what is the mass of the byproduct of this reaction? (Note: Assume that the amino acids were not modified by protecting groups.) A. 17 amu B. 18 amu C. 32 amu D. 44 amu

B. This is an Organic Chemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is B because the formation of a peptide bond is accompanied by the formation of water as a by-product, and the mass of water is 18 amu. It is a Scientific Reasoning and Problem Solving question because one must understand (1) that water is released as a by-product of peptide bond formation from the OH of the carboxyl group and the NH of the amino group, and (2) that the mass of H2O is the sum of its atomic masses.

Which type of membrane transport is directly affected by cardiac glycosides? A. Simple diffusion B. Facilitated diffusion C. Primary active transport D. Secondary active transport

C. This is a Biochemistry question that falls under the content category "Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms." The answer to this question is C because The Na+K+ ATPase is an example of primary active transport. It is a Knowledge of Scientific Concepts and Principles question because it requires recall of the basic scientific concept of membrane transport.

The enzyme used in the blood glucose meter described in the passage is classified as: A. a transferase. B. an isomerase. C. an oxidoreductase. D. a hydrolase.

C. This is a Biochemistry question that falls under the content category "Principles of chemical thermodynamics and kinetics." The answer to this question is C because Reaction 2 is an oxidation of glucose, and thus the enzyme that catalyzes this reaction is classified as an oxidoreductase. It is a Knowledge of Scientific Concepts and Principles question because the enzyme classification system is a fundamental biochemical concept.

Based on the information in the passage and in Figure 1, what effect does epigenetic modification have on iM pH-dependent denaturation? A. Both methylation and hydroxymethylation result in significantly decreased stability because cytosine is more readily deprotonated. B. Both methylation and hydroxymethylation result in significantly decreased stability because cytosine is more readily protonated. C. Only hydroxymethylation results in significantly decreased stability because cytosine is more readily deprotonated. D. Only hydroxymethylation results in significantly decreased stability because cytosine is more readily protonated.

C. This is a Biochemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is C because the drop in pK of the transition denotes a decrease in stability. Because DNA unfolding occurs as the pH increases, it can be inferred that this is due to cytosine deprotonation. Since 5hmC-WT has the lowest pK, hydroxymethylation decreases the stability by increasing the acidity of cytosine. It is a Data-based and Statistical Reasoning question because it requires interpreting graphical data in order to draw scientific conclusions.

One consequence of advanced malnutrition is reduced amounts of plasma proteins in the blood. This condition would most likely cause the osmotic pressure of the blood to: A. decrease, resulting in a decrease of fluid in the body tissues. B. increase, resulting in a decrease of fluid in the body tissues. C. decrease, resulting in an increase of fluid in the body tissues. D. increase, resulting in an increase of fluid in the body tissues.

C. This is a Biology question that falls under the content category "Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms." The answer to this question is C because large plasma proteins, such as albumin, in the blood increase the osmotic pressure of the blood, which in turn, increases the return of fluid to the circulatory system from the body tissues. Therefore, with malnutrition, the osmotic pressure of the blood would decrease resulting in an increase of fluid in the body tissues. It is a Scientific Reasoning and Problem Solving question because it involves prediction of the outcome of a scientific scenario.

Which of the following best describes the chemical energy that is derived from the Krebs cycle? Energy is produced in the forms of: A. ATP, which directly supplies energy for many cellular processes, and NAD+, which supplies energy for the electron transport chain. B. NAD+, which directly supplies energy for many cellular processes, and ATP, which supplies energy for the electron transport chain. C. ATP, which directly supplies energy for many cellular processes, and NADH, which supplies energy for the electron transport chain. D. NADH, which directly supplies energy for many cellular processes, and ATP, which supplies energy for the electron transport chain.

C. This is a Biology question that falls under the content category "Principles of bioenergetics and fuel molecule metabolism." The answer to this question is C because the Krebs cycle produces both ATP and NADH but not NAD+. ATP directly supplies energy for many cellular processes, such as muscle contraction, and NADH, which is used in the electron transport chain. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of the net molecular and energetic results of respiration processes.

Monkeys were raised on a diet of either high- or low-quality protein and then were given free access to high- and low-quality protein diets. The diet preference for both groups of monkeys is shown. (Note: Both groups of monkeys consumed the same amount of food.)The data indicate that: A. the feeding behavior of monkeys was not affected by either prior diet type. B. prior protein insufficiency was a stronger predictor of future feeding behavior than prior protein sufficiency. C. prior feeding history influenced future feeding behavior in monkeys raised on a high-quality protein diet only. D. the feeding behavior was solely determined by both prior diet types.

C. This is a Biology question that falls under the content category "Social interactions." The answer to this question is C because the data indicate that monkeys raised on high-quality protein retained a pronounced preference for high-quality protein. A is incorrect because monkeys raised on a high-quality protein had a strong preference for high-quality protein, whereas monkeys raised on a low-quality protein had no preference. B is incorrect because monkeys raised on low-quality protein had no preference in future feeding behavior. D is incorrect because the data indicate that monkeys raised on high-quality protein retained a pronounced preference for high-quality protein. It is a Data-based and Statistical Reasoning question because the question involves identifying a correct conclusion from data presented in a figure.

Based on the passage, in which of the following ways is the action of serotonin on postsynaptic receptors most likely terminated? A. Alteration of the receptor's affinity for serotonin B. Production of mutant enzymes involved in serotonin synthesis C. Transportation of released serotonin back into the presynaptic terminal D. Absorption of the serotonin-receptor complex into the postsynaptic compartment

C. This is a Biology question that falls under the content category "Structure and functions of the nervous and endocrine systems and ways in which these systems coordinate the organ systems." The answer to this question is C because the passage states that antidepressant drugs act to increase the amount of serotonin in the synaptic space. Therefore, the action of serotonin on postsynaptic receptors would be terminated by the removal of serotonin from the synaptic space. This would occur by transport of released serotonin back into the presynaptic terminal, an action that SSRIs block. It is a Knowledge of Scientific Concepts and Principles question because it requires recognizing the correct scientific principle based on the information presented in the passage.

Large amounts of protein are found in the urine of a patient. Based on this information, which portion of the nephron is most likely malfunctioning? A. Collecting duct B. Distal tubule C. Glomerulus D. Loop of Henle

C. This is a Biology question that falls under the content category "Structure and integrative functions of the main organ systems." The answer to this question is C because in healthy individuals, the structure of the glomerular capillaries prevents the entry of large molecules, such as proteins, into the filtrate. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of the structure and function of the different parts of the mammalian excretory system.

Based on the passage, which of the following conditions most likely contributed to the boy's weight loss? A. A decrease in the ability of the villi to propel food into the large intestine for the completion of digestion B. An increase in enzyme secretion by the mucosal epithelium into the intestinal lumen, leading to excess digestion of nutrients C. A decrease in the surface area of the small intestine, leading to a decrease in nutrient absorption D. A decrease in enzyme secretion by the mucosal epithelium into the intestinal lumen, leading to incomplete digestion of nutrients

C. This is a Biology question that falls under the content category "Structure and integrative functions of the main organ systems." The answer to this question is C because the passage states that gluten, the factor that contributed to the boy's weight loss, causes intestinal villi atrophy. Villi atrophy results in a decrease in the surface area of the small intestine, leading to a decrease in nutrient absorption. It is a Scientific Reasoning and Problem Solving question because the question requires the test-taker to form a hypothesis based on the information presented in the passage.

What type of reaction is occurring between I2 and Zn? A. Acid-base (neutralization) B. Precipitate formation C. Oxidation-reduction D. Chelate formation

C. This is a General Chemistry question that falls under the content category "Atoms, nuclear decay, electronic structure, and atomic chemical behavior." The answer to this question is C, because both zinc and iodine change oxidation states during the reaction. It is a Knowledge of Scientific Concepts and Principles question because you must recognize and identify a reaction as oxidation-reduction based on the concept of oxidation states.

What is the concentration of hydroxide ion for the solutions with the highest pH that was studied? A. 10-10 B. 10-6 C. 10- 4 D. 10-2

C. This is a General Chemistry question that falls under the content category "Unique nature of water and its solutions." The answer to this question is C because, at the highest pH tested (10) the [H3O+] is 10-10 M. This means that [OH-] is 10-4 M, because [H3O+] × [OH-] = 10-14 for aqueous solutions at 25°C. It is a Scientific Reasoning and Problem Solving question because you must determine and use scientific formulas (converting pH to [H3O+] and then calculating [OH-]) to solve a problem.

What is the resistivity of the best-performing PANI described in the passage? A. 0.002 Ω•cm B. 50 Ω•cm C. 200 Ω•cm D. 500 Ω•cm

C. This is a Physics question that falls under the content category "Electrochemistry and electrical circuits and their elements." The answer to this question is C because resistivity is the inverse of the conductivity, which is 1/5.0 × 10-3 (Ω∙cm)-1 = 200 Ω∙cm. It is a Scientific Reasoning and Problem Solving question because it asks you to determine and use scientific formulas to solve problems.

If the researchers wanted to study the impact of emotions on cardiac mortality during the holidays, which concept are they LEAST likely to address? A. Learned helplessness B. Locus of control C. Fundamental attribution error D. Self-efficacy

C. This is a Psychology question that falls under the content category "Self-identity." The answer to this question is C because the fundamental attribution error, which refers to an observer's bias in favor of internal attributions in explaining another person's behavior, would have no bearing on the research described in the question. Each of the distractors has the potential to regulate the impact of emotions on cardiac mortality. It is a Knowledge of Scientific Concepts and Principles question because the question involves understanding of basic concepts from behavioral science.

In an extension of the research, ten individuals were recruited for an information session on the energy-saving program. Six of the ten individuals were colleagues and unanimously agreed to the program. The remaining four individuals also agreed to the program. Which concept is best represented by this scenario? A. Bystander effect B. Social loafing C. Groupthink D. Assimilation

C. This is a Psychology question that falls under the content category "Social processes that influence human behavior." The answer to this question is C because, in this example, the researchers were testing whether individuals, when they are part of a cohesive in-group, will agree to the same behavior, which is an example of groupthink. It is a Knowledge of Scientific Concepts and Principles question because the question requires the recognition of a basic concept from behavioral science.

Which statement CANNOT be concluded from Table 1? A. Americans' confidence in religious institutions has declined from 1973 to 2013. B. More than 60% of Americans had a great deal or quite a lot of confidence in organized religion in 1973. C. The change in percentage of Americans who have very little confidence in organized religion between 1973 and 2013 is statistically significant. D. The change in percentage of Americans who have very little confidence in organized religion between 1973 and 2013 represents an overall increase.

C. This is a Sociology question that falls under the content category "Understanding social structure." The answer to this question is C because the table does not indicate statistical significance. Thus, a conclusion cannot be made regarding whether the percentage increase is statistically significant. It is a Data-based and Statistical Reasoning question because the question involves understanding what information can be concluded from a table.

A researcher criticizes the methods used in the study, stating that teachers' ratings may not be a valid way of assessing the students' emotional problems. Which hypothetical finding is most likely to reduce this concern? A. A positive correlation between the number of emotional problems observed in students and the number of classmates reading below grade level B. A negative correlation between the number of emotional problems observed in students and the number of disruptions experienced by the teacher per day C. A positive correlation between the teachers' ratings of the number of emotional problems observed in students and the parents' rating of the same variable D. A negative correlation between the teachers' ratings of the number of emotional problems observed in students at two different times

C. This is a Psychology question that falls under the content category "Responding to the world." The answer to this question is C because when two independent measures of the same variable converge, it supports the validity of both measures. It is a Reasoning about the Design and Execution of Research question because the question involves determining how additional information can be used to judge the validity of specific measures of the variables (teachers' ratings of children's behavioral and emotional problems).

Which experimental condition is NOT necessary to achieve reliable data for Michaelis-Menten enzyme kinetics? A. Initial velocity is measured under steady state conditions. B. Solution pH remains constant at all substrate concentrations. C. The concentration of enzyme is lower than that of substrate. D. The reaction is allowed to reach equilibrium before measurements are taken.

D. This is a Biochemistry question that falls under the content category "Principles of chemical thermodynamics and kinetics." The answer to this question is D because once the reaction reaches equilibrium, measurement of Vo will be impossible and the kinetic data will look the same regardless of substrate concentration. Hence, response D is not necessary (nor desirable) to achieve reliable data for Michaelis−Menten enzyme kinetics. In contrast, Distractors A−C are essential to obtain reliable Vo versus substrate concentration data to calculate KM and Vmax using Michaelis−Menten enzyme kinetics. It is a Reasoning about the Design and Execution of Research question because the question probes the experimental conditions required to obtain reliable data.

A common column material used in size-exclusion chromatography is dextran, a polysaccharide of glucose. Which type of interaction most likely occurs between proteins and the dextran column material? A. Aromatic B. Hydrophobic C. Salt bridge D. Hydrogen bonding

D. This is a Biochemistry question that falls under the content category "Separation and purification methods." The answer to this question is D because a polysaccharide of glucose has numerous hydroxyl groups that can hydrogen bond to the polar side chains that are typically exposed on a protein surface. It is a Scientific Reasoning and Problem Solving question because it requires making a correlation between scientific principles, associating structural features with intermolecular forces.

Allosteric inhibition of an enzyme involves which of the following events? A. Binding of an inhibitor uncompetitively in place of the substrate B. Binding of an inhibitor competitively in place of the substrate C. Binding of an inhibitor noncompetitively in place of the substrate D. Binding of an inhibitor to a site other than the substrate binding site

D. This is a Biochemistry question that falls under the content category "Structure and function of proteins and their constituent amino acids." The answer to this question is D because allosteric inhibition involves binding of an inhibitor to a site other than the substrate binding site. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of the control of enzyme activity.

Which type of catalytic activity is most likely missing from cFLIP? A. Oxidoreductase activity B. Lyase activity C. Isomerase activity D. Hydrolase activity

D. This is a Biochemistry question that falls under the content category "Structure and function of proteins and their constituent amino acids." The answer to this question is D because the passage notes that cFLIP is a homolog of a protease, caspase-8. Therefore, it is most likely that the catalytic activity that is missing from cFLIP is hydrolase activity. It is a Scientific Reasoning and Problem Solving question because it requires determining which enzymatic activity corresponds to an enzyme described in the passage.

Which atom is most likely involved in the coordination of calcium ions found in HRP? A. Hydrogen B. Carbon C. Nitrogen D. Oxygen

D. This is a Biochemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is D because an atom must be a Lewis base to coordinate to calcium ions, and oxygen is the only Lewis basic atom present in the side chains or backbones of the listed amino acids that has either a partially negative charge (in the peptide backbone or Ser side chain) or a negative charge (in the Asp side chain). The only other Lewis basic atom present is nitrogen (distractor C), which has a partially positive chain in the peptide backbone due to resonance, and is thus less likely to coordinate calcium ions. It is a Scientific Reasoning and Problem Solving question because its solution requires (1) knowing that Lewis bases coordinate with cations, (2) recognizing which side chains and backbones are Lewis bases, and (3) understanding the effect of charge on the strength of Lewis base interactions with cations.

What is the correct expression for the ΔG′° for the transition observed in the experiments described in the passage? A. ΔG′° = -RTe([native]/[unfolded]) B. ΔG′° = -RTe([unfolded]/[native]) C. ΔG′° = -RTln([native]/[unfolded]) D. ΔG′° = -RTln([unfolded]/[native])

D. This is a Biochemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is D because the equilibrium constant for DNA unfolding is Keq = [unfolded]/[native] as the unfolded DNA is considered to be a product. Thus, ΔG′° = −RTlnKeq = −RTln([unfolded]/[native]). It is a Scientific Reasoning and Problem Solving question because it requires a scientific equation and its application to experimental data.

Which action(s) could contribute to the positive inotropic effect of digoxin on cardiac myocytes? I.Decrease transport of Ca2+ to the extracellular environment. II. Increase availability of intracellular Ca2+ to bind to troponin. II. Increase overall Ca2+ stores in the sarcoplasmic reticulum. A. II only B. III only C. I and II only D. I, II, and III

D. This is a Biology question that falls under the content category "Structure and integrative functions of the main organ systems." The answer to this question is D because all of these actions will lead to an increase in intracellular calcium levels, resulting in enhancement of the contractile force of the heart. It is a Scientific Reasoning and Problem Solving question because it requires scientific evaluation of various scenarios to determine their outcomes.

Which series shows the order in which filtrate passes through the tubular regions of a nephron? A. Bowman's capsule → loop of Henle → proximal tubule → distal tubule → collecting duct B. Proximal tubule → collecting duct → loop of Henle → Bowman's capsule → distal tubule C. Collecting duct → Bowman's capsule → loop of Henle → proximal tubule → distal tubule D. Bowman's capsule → proximal tubule → loop of Henle → distal tubule → collecting duct

D. This is a Biology question that falls under the content category "Structure and integrative functions of the main organ systems." The answer to this question is D because blood is filtered into Bowman's space within Bowman's capsule and then moves sequentially through the proximal tubule, the loop of Henle, the distal tubule, and the collecting duct. It is a Knowledge of Scientific Concepts and Principles question because it requires knowledge of the structure and function of the different parts of the nephron.

Which type(s) of restriction enzyme(s) can recognize the HIF binding sequence? A restriction enzyme that has: I. a four-base recognition sequence II. a six-base recognition sequence III. an eight-base recognition sequence A. I only B. II only C. III only D. I and II only

D. This is a Biology question that falls under the content category "Transmission of genetic information from the gene to the protein." The answer to this question is D because only the CCCGGG within the HIF binding sequence is palindromic. Therefore, only a restriction enzyme that recognizes a four-base sequence or a six-base sequence can recognize this sequence within the HIF binding sequence. It is a Reasoning about the Design and Execution of Research question because it requires reasoning about use of restriction enzymes in research.

What is the identity of the substance that has undergone net reduction after the Reaction 1 is complete? A. NADP+ B. FAD C. H2O2 D. O2

D. This is a General Chemistry question that falls under the content category "Atoms, nuclear decay, electronic structure, and atomic chemical behavior." The answer to this question is D, because oxygen is the final acquirer of electrons in the reaction and is therefore reduced. It is a Knowledge of Scientific Concepts and Principles question because you must recognize and identify a substance which is reduced based on the scientific concept of oxidation states.

That the electric field is uniform between the electrodes means that the electric field lines: A. are more closely spaced at the positive electrode than at the negative one. B. intersect halfway between the electrodes. C. are more closely spaced at the negative electrode than at the positive one. D. are equally spaced at both electrodes and between them.

D. This is a Physics question that falls under the content category "Electrochemistry and electrical circuits and their elements." The answer to this question is D because, by definition, electric field lines are equally spaced in a uniform field. It is a Knowledge of Scientific Concepts and Principles question because it asks you to recognize correct scientific principles by identifying the correlation between the concept of uniform electric field and the geometrical representation of such a field with equally spaced, parallel lines.

The regulation of which neurotransmitter is implicated in the specific finding reported with Study 1? A. Acetylcholine B. GABA C. Endorphins D. Serotonin

D. This is a Psychology question that falls under the content category "Individual influences on behavior." The answer to this question is D because the specific finding from Study 1 states that aggression and oppositional behaviors had the strongest association with the risk of hunger. Serotonin is involved in the regulation of both mood (specifically, aggression) and appetite (it is also used to regulate intestinal movements). The distractors are other neurotransmitters that are not specifically involved in the hunger drive, mood, or aggressive behavior. It is a Knowledge of Scientific Concepts and Principles question because the question involves understanding how different neurotransmitters are involved in motivation, emotion, behavior, etc.

Which critique of laboratory research on memory for emotional events is concerned with generalizability? A. Potential confounding variables are not always controlled in laboratory studies. B. Retention tests employed in laboratory studies are usually concerned with factual information rather than emotions. C. The intensity of emotional responses is more accurately measured after the event in laboratory studies. D. Memories and emotional experiences in real life are very different from those generated in laboratory studies.

D. This is a Psychology question that falls under the content category "Making sense of the environment." The answer to this question is D because generalizability refers to external validity, which is the extent to which the results of a scientific investigation would generalize to other settings and populations. It is dependent on the extent to which the processes studied in the investigation represent the processes presumed to be operating outside the laboratory. It is a Scientific Reasoning and Problem Solving question because the question involves reasoning about the relationship between psychological phenomena as they normally occur and findings from laboratory research.

At the end of Study 2, the researchers' recommendation suggests that parents in food-insecure households are subject to which role dynamic? A. Role engulfment B. Role confusion C. Role conflict D. Role strain

D. This is a Sociology question that falls under the content category "Social interactions." The answer to this question is D because the relevant statement in the passage refers to how researchers recommended interventions focusing on parents who experience stress from trying to satisfy both their children's needs and their own needs. By identifying tension stemming from the parental role, the recommendation suggests role strain (which refers to stress from different expectations associated with a single role). For parents with depression, the parental role can cause competing obligations of satisfying their children's needs when they are coping with psychological distress (and thus are unable to meet their own needs). It is a Knowledge of Scientific Concepts and Principles question because the question involves recognizing the concept that best illustrates something that is being portrayed in the passage.

Which statement is NOT consistent with a conflict theoretical analysis of the findings in the passage? A. Religion is an instrument of social control. B. Religion helps to legitimate inequality in society. C. Religion encourages passive acceptance of material conditions. D. Religion helps to increase social solidarity.

D. This is a Sociology question that falls under the content category "Understanding social structure." The answer to this question is D because it represents a functionalist understanding of religion, with the reference to social solidarity. The other options each articulate how a conflict theorist, focused on social control and social inequality, would view the role of religion in society. It is a Scientific Reasoning and Problem Solving question because the question involves understanding how different theoretical perspectives would be applied to research findings.

The relative thermodynamic stability of isomeric organic compounds can be inferred from which of the following types of experimental data? A. Boiling points B. UV-visible absorption spectra C. Mass spectroscopic fragmentation patterns D. Heats of combustion

D. This is an Organic Chemistry question that falls under the content category "Nature of molecules and intermolecular interactions." The answer to this question is D because the relative thermodynamic stability of isomers can be determined based on the amount of heat produced when the compounds are combusted; less heat, greater stability. It is a Reasoning about the Design and Execution of Research question because one must choose the appropriate experimental data to answer the question.

In the absence of digoxin treatment, hydrolysis of one molecule of ATP results in which combination of ion movements across the myocardial cell membrane? A. 1 K+ out; 2 Na+ in B. 2 Na+ out; 1 K+ in C. 3 K+ out; 2 Na+ in D. 3 Na+ out; 2 K+ in

D. This is a Biochemistry question that falls under the content category "Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms." The answer to this question is D because Na+K+ ATPase transports 3 Na+ outside of the cell and 2 K+ inside of the cell per molecule of ATP hydrolyzed. It is a Knowledge of Scientific Concepts and Principles question because it requires recall of the mechanism of action of the Na+K+ ATPase.

One potential complication of celiac disease is osteoporosis, which can occur as the body utilizes bone tissue to maintain adequate levels of calcium in the blood. The most effective way for the body to utilize bone tissue to increase blood calcium levels would be to simultaneously: A. increase osteoblast activity and decrease osteoclast activity. B. increase osteoblast activity and increase osteoclast activity. C. decrease osteoblast activity and decrease osteoclast activity. D. decrease osteoblast activity and increase osteoclast activity.

D. This is a Biology question that falls under the content category "Structure and integrative functions of the main organ systems." The answer to this question is D because while osteoblasts function to build and repair bone, osteoclasts break down bone. Therefore, to increase calcium levels in the blood, osteoblast activity should be decreased and osteoclast activity should be increased to release stored calcium from the bone to the bloodstream. It is a Reasoning about the Design and Execution of Research question because it requires the identification of the correct design strategy to alleviate abnormalities that result from a disease state.

A researcher attempts to replicate studies 1 and 2 with a group of 5-year-olds by using simplified versions of the games. Which cognitive limitation is most likely to inhibit the participants' performance on the dependent variables? A. Lack of object permanence B. Limited understanding of conservation C. Centration D. Egocentrism

D. This is a Psychology question that falls under the content category "Making sense of the environment." The answer to this question is D because, according to Piaget's theory of cognitive development, five-year-olds are in the preoperational period in which they are presumed to be limited by egocentrism (viewing the world only from their own perspective). This limitation is likely to interfere with performance on the tasks in studies 1 and 2, both of which require some degree of perspective taking. It is a Scientific Reasoning and Problem Solving question because the question involves making a prediction based on your understanding of the task requirements and the phenomenon of egocentrism.

Suppose that a blood vessel of cross-sectional area A carries microbubbles at a speed v into a capillary bed. If the capillary bed is made up of n capillaries, each with cross-sectional area a, with what speed will the blood flow in the capillary bed? B. A/na *v

This is a Physics question that falls under the content category "Importance of fluids for the circulation of blood, gas movement, and gas exchange." The answer to this question is B because, according to the continuity equation, if u is the speed of flow in the capillary bed, then A × v = n × a × u, so u = A × v/(n × a). It is a Scientific Reasoning and Problem-solving question because it asks you to determine and use scientific formulas to solve problems.