AAMC PRACTICE QUESTIONS
A wound that penetrates the rib cage and lets air into the right pleural cavity stops air flow into the right lung because the: a. lung cannot be expanded. b. rib cage cannot be expanded. c. diaphragm cannot be lowered. d. air dries and stiffens the lung.
(loss of negative pressure) Answer Key: A Non-forced inspiration occurs when the diaphragm and muscles between the ribs (intercostal muscles) contract. The ribs attached at the sternum and spine lift in what is called a "bucket-handle" motion and the diaphragm flattens. These motions increase the volume of the thoracic cavity. Between the lung and the thoracic wall is a space, the pleural cavity. As the volume of the thoracic cavity increases, atmospheric pressure presses against the inside of the flexible, elastic lung tissue forcing it to conform to the thoracic wall. Air thus enters the lung as it expands with the thorax. If the thoracic wall is pierced (causing what is known as a sucking chest wound), air enters the pleural cavity. The air pressure inside and outside the lung balance causing the lung to elastically collapse and preventing air intake. The rib cage can still expand (so choice B is incorrect), the diaphragm can still contract (so choice C is incorrect), but the lung cannot be expanded in response, so the correct response is A. Choice D is incorrect because the effect is immediate and it would take some time for the lung to dry and stiffen, if indeed that would happen at all.
If sounds produced by the human vocal cords are approximated as waves on a string fixed at both ends, and the average length of a vocal cord is 15 mm, what is the fundamental frequency of the sound? (Note: Use 3 m/s for the speed of sound through the vocal cord.) 10 Hz 100 Hz 1000 Hz 10,000 Hz
100Hz (be familiar with human voice frequency ranges --> 80-150) Speed of sound and frequency for fixed string can be used: (fundamental = f = v/2L --> 3ms/(30x10^-3)
What is the ribosome sizes of eukarya and prokarya respectively? (combined subunits)
80S for eukarya, and 70S for prokarya
Dewlaps that reflect UV light would evolve by natural selection only if: A. individuals with UV-reflective dewlaps produced more offspring than did individuals without them. B. individuals with UV-reflective dewlaps were better able to communicate than individuals without them. C. individuals with UV-reflective dewlaps were less subject to predation than individuals without them. D. individuals with UV-reflective dewlaps mated more frequently than did individuals without them.
A All about number of viable offspring, not necessarily equitable with amount of reproductive mating instances
What would be the result of complete removal of the parathyroid glands? A. Severe neural and muscular problems due to deficiency of calcium in the plasma B. An increase in calcitonin production to compensate for calcium deficiency in the plasma C. A drastic change in the ratio of mineral to matrix tissue in bones D. Calcification of some organs due to accumulation of calcium in the plasma
A Given the function of PTH, lack of this hormone results in hypocalcemia...results in symptoms described by A
In which organelle of a eukaryotic cell is the pyrimidine uracil, as part of uridine triphosphate (UTP), incorporated into nucleic acid? The nucleus The Golgi bodies The ribosomes The endoplasmic reticulum
A Incorporated into the DNA during transcription which we know takes place within the nucleus
The amitotic macronuclei of the asexual progeny in Tetrahymena and the cytoplasm of the ova-producing cells of female vertebrates share a common feature in that both: undergo uneven division. contain uneven amounts of nuclear material. regulate their contents by adding or skipping an S phase. are apportioned at mitosis.
A We know that vertebrate oocytes divide into uneven daughter cells (ovum and polar bodies)...as described by being amitotic, the macronuclei divide similarly
Most bacterial cells and human cells are alike in: the ability to produce ATP via ATP synthase. the chemical composition of their ribosomes. their enclosure within cell walls. the shape of the self-replicating structures that carry their DNA.
A the ability to produce ATP via ATP synthase is common to both bacterial and human cells. The chemical composition of prokaryotic and eukaryotic ribosomes (B), although similar, is distinct enough that several types of antibiotics are able to preferentially target prokaryotic ribosomes over eukaryotic ribosomes (remember 40S vs 30S etc)
Would an increase in the level of plasma aldosterone be expected to follow ingestion of excessive quantities of NaCl? No; aldosterone causes Na+ reabsorption by kidney tubules. No; aldosterone causes Na+ secretion by kidney tubules. Yes; aldosterone causes Na+ reabsorption by kidney tubules. Yes; aldosterone causes Na+ secretion by kidney tubules.
A (know this)
In human females, mitotic divisions of oogonia that lead to formation of presumptive egg cells (primary oocytes) occur between: fertilization and birth only. fertilization and puberty only. birth and puberty only. puberty and menopause only.
A (tricky wording) Fertilization and birth only We know that all mitosis happens before birth --> set number of primary oocytes
Suppose that an extract from a muscle cell contains only the following: all the enzymes of the glycolytic pathway, including the enzyme that converts pyruvate to lactate; phosphate and other salts; NAD+ and ADP. When the extract is incubated anaerobically and glucose is introduced, neither pyruvate nor lactate is produced. What must be added in order for pyruvate to be made? O2 ATP NADH Acetyl-coenzyme A
ATP (hexokinase etc needs ATP)
An object is placed upright on the axis of a thin convex lens at a distance of four focal lengths (4f) from the center of the lens. An inverted image appears at a distance of 4/3f on the other side of the lens. What is the ratio of the height of the image to the height of the object? 1/3 3/4 4/3 3/1
Answer Key: A The ratio of object to image distance equals the ratio of object to image height. The ratio of image to object height is found by rearranging the ratios to give (4f/3)/4f = 1/3. The image is demagnified by a factor of 3. Thus, answer choice A is the best answer.
Which of the following procedures would be LEAST likely to prevent bacterial synthesis of the superantigen protein? A. Adding tRNA nucleotides that can bind to mRNA and bacterial ribosomes B. Adding a repressor protein that binds to the operator site of the bacterial superantigen gene C. Adding a specific complementary nucleic acid sequence that can bind to mRNA transcribed from the superantigen gene D. Adding a stop codon within the bacterial superantigen gene
Answer Key: A The stem asks students to identify the procedure that would be LEAST likely to prevent synthesis of the superantigen. Foils B (binding of the operator), C (binding of the mRNA), and D (insertion of a stop codon) would all be effective ways to prevent synthesis of the superantigen. Adding tRNA nucleotides would be unlikely to prevent synthesis of the antigen. Therefore, the key is A.
Uracil is produced from cytosine as a result of a conversion of: an amine group to a carbonyl group. a carbonyl group to an amine group. an amine group to a methyl group. a carbonyl group to a methyl group.
Answer Key: A This Biochemistry question falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer is A because in the deamination of cytosine, the amine group of cytosine is replaced with a carbonyl group, resulting in the structure of uracil. This is a Knowledge of Scientific Concepts and Principles question because you are asked to recall the structures of uracil and cytosine and make a comparison between them.
Phosphoenolpyruvate (PEP) transfers a phosphate group to ADP in a spontaneous reaction, and ATP transfers a phosphate group to glucose in a spontaneous reaction, both under standard conditions. Based on this information, what is the relationship between the absolute values of the standard free energies of hydrolysis of PEP, ATP, and glucose 6-phosphate (G6P)? PEP > ATP > G6P G6P > ATP > PEP ATP > G6P > PEP PEP > G6P > ATP
Answer Key: A This is a Biochemistry question that falls under the content category "Principles of bioenergetics and fuel molecule metabolism." The answer is A because the molecule with the most negative standard free energy of hydrolysis is also the molecule that is able to spontaneously transfer a phosphate group to create phosphorylated compounds of lower free energy. Therefore, if ATP can spontaneously transfer phosphate to glucose and PEP can spontaneously transfer phosphate to ADP, then PEP has the most negative standard free energy of hydrolysis followed by ATP. The absolute value of the most negative number is the largest value. This is a Scientific Reasoning and Problem Solving question because you must use the scientific model of phosphate transfer to make a claim about free energy of hydrolysis. (think dG = - for spontaneous thus reactants have less energy than products)
What is the dependent variable in an experiment that determines the Michaelis-Menten kinetic parameters of an enzyme? Initial velocity Initial substrate concentration Enzyme concentration Fraction of substrate bound
Answer Key: A This is a Biochemistry question that falls under the content category "Structure and function of proteins and their constituent amino acids." The answer to the question is A because enzymatic assays should be conducted in this way to generate a curve of velocity versus substrate concentration, which can then be used to determine the Vmax and KM of the reaction. It is a Reasoning about the Design and Execution of Research question because you must identify the necessary variable in an experiment to generate the correct data.
A study is conducted in which researchers observe how physicians deal with role strain when treating patients with terminal illnesses. This study is best described as following which type of research design? Ethnographic Comparative Experimental Cross-sectional
Answer Key: A This scenario refers to ethnographic research, which involves observing social interactions in real social settings. Studying the experience of role strain through observation can increase our understanding of how physicians cope with the challenging demands of extending life with interventions while accepting the reality of death.
An electrochemical cell is designed to produce pure copper from CuSO4. An increase in which of the following cell conditions will most effectively increase the rate at which pure copper is produced? The concentration of SO42+(aq) The current of electricity The size of the cathode The size of the anode
Answer Key: B An electrolytic cell drives a non-spontaneous reaction using electrical energy. In the electrolytic cell, electrons are driven in through the cathode and drawn out through the anode. The rate at which this occurs is the current. By increasing the current, electrons are forced in faster, increasing the rate of reduction, and are withdrawn faster thus increasing the rate of oxidation. Answer choice B is the best answer.
Suppose that a stream of fluid flows steadily through a horizontal pipe of varying cross-sectional diameter. Neglecting viscosity, where is the fluid pressure greatest? At the intake point At the point of maximum diameter At the point of minimum diameter At the point of maximum change in diameter
Answer Key: B Bernoulli's equation for horizontal fluid flow (when viscosity is neglected) states that the pressure plus kinetic energy density of the fluid is constant. If the fluid velocity falls, the kinetic energy density decreases so the pressure increases. The fluid velocity is lowest where the diameter of the pipe is a maximum. Thus, the pressure is greatest where the diameter is a maximum.
An unknown solid weighs 31.6 N. When submerged in water, its apparent weight is 19.8 N. What is the specific gravity of the unknown sample? 2.96 2.68 2.02 1.68
Answer Key: B The buoyant force on the solid is the difference between its weight (31.6 N) and its apparent weight in water (19.8 N). This force equals the weight of the water displaced, which, in turn, equals the product of the volume of the solid and the density of water. The specific gravity of the solid, i.e., the ratio of its weight to the weight of an equal volume of water, is then: 31.6/(31.6 -19.8) = 2.68. The correct answer is B.
Which of the following hormones is LEAST directly regulated by the anterior pituitary? Cortisone Epinephrine Progesterone Thyroxin (for your answer...what IS it directly regulated by?)
Answer Key: B The correct answer is option B, epinephrine. Epinephrine is secreted by the adrenal medulla and its secretion is controlled by the autonomic nervous system. Secretion of the other three hormones is regulated by secretion of anterior pituitary hormones. Cortisone secretion is regulated by adrenocorticotropic hormone (ACTH), progesterone by luteinizing hormone (LH), and thyroxin by thyroid stimulating hormone (TSH).
A gas that occupies 10 L at 1 atm and 25oC will occupy what volume at 500 atm and 25oC? A. Exactly 0.020 L B. Somewhat more than 0.02 L because of the space occupied by the individual gas molecules C. Somewhat more than 0.02 L because of the repulsion's between the individual gas molecules D. Somewhat more than 0.02 L because of the increased number of collisions with the sides of the container
Answer Key: B The ideal gas law makes the assumption that molecules have no volume. This assumption is adequate when the gas is at 1 atm, but when the pressure is increased to 500 atm the volume of the gas molecules is no longer negligible.
The following reaction occurs spontaneously. Cd(s) + 2 H+(aq) → Cd2+(aq) + H2(g) Which of the following has the highest electron affinity? Cd(s) H+(aq) Cd2+(aq) H2(g)
Answer Key: B The reaction equation shows the reduction of H+ by Cd. Because the H+ accepts the electron readily from Cd, it can be determined that H+ has the highest electron affinity.
If ocean waves strike the shore every 3.0 s and the horizontal distance between adjacent crests and troughs is 1.0 m, what is the average speed of the waves? 0.33 m/s 0.67 m/s 1.5 m/s 3.0 m/s
Answer Key: B The speed of a wave is given by the product of its frequency times its wavelength: v =fλ. The wave frequency is 1/(3 s); the wavelength is 2 × 1 m because a crest and the adjacent trough are a half wavelength apart. The wave speed is therefore 2 m/3 s = 0.67 m/s. Thus answer B is correct.
A rat in a shuttle box is presented with a tone followed by an electric shock. It can jump over the barrier to the other side of the shuttle box where no shock is delivered. This procedure is repeated over a number of trials. The rat will be conditioned through which type of reinforcement? Positive reinforcement Negative reinforcement Positive punishment Negative punishment
Answer Key: B This is a Psychology question that falls under content category "Attitude and behavior change." The answer to this question is B because when a response results in escape from an aversive stimulus, it is an example of negative reinforcement. It is a Knowledge of Scientific Concepts and Principles question because it requires knowing the definition of negative reinforcement.
A researcher is interested in assessing the size of a patient's brain ventricles. Which method(s) is(are) appropriate for this purpose? I. An EEG II. A CAT scan III. A PET scan I only II only I and III only II and III only
Answer Key: B This is a Psychology question that falls under content category "Individual influences on behavior." The answer to this question is B because the researcher is interested in the structure of the brain, which can be studied through a CAT scan. It is a Knowledge of Scientific Concepts and Principles question because it requires knowing the basic properties of different methods of studying the brain.
Which of the following is a binocular depth cue? Motion parallax Retinal disparity Relative height Relative size
Answer Key: B This is a Psychology question that falls under content category "Sensing the environment." The answer to this question is B because retinal disparity requires input from both retinas. It is a Knowledge of Scientific Concepts and Principles question because it requires knowing the definitions of depth cues.
An individual experiences shortness of breath and panic in confined spaces. To overcome this reaction, the individual decides to spend time in a confined space until the shortness of breath and panic response are eliminated. The patient is using which method to eliminate the symptoms? Extinction of an operantly conditioned response Extinction of a classically conditioned response Counter conditioning Aversive conditioning
Answer Key: B This is a Psychology question that falls under the content category "Attitude and behavior change." The answer to this question is B because phobic responses are usually acquired through classical conditioning. Exposing oneself to the conditioned stimulus (in this case, the confined space) until the conditioned phobia is no longer elicited is consistent with the extinction of a classically conditioned response. It is a Scientific Reasoning and Problem Solving question because it requires using the information from the stem to derive the strategy that the individual is using to treat his/her phobia.
Which of the following substances is most likely to be more soluble in 1.0 M HCl than in 1.0 M NaOH? AgCl Pb(OH)2 CaF2 HI
Answer Key: B When an ionic substance dissolves, it dissociates into its constituent ions. The solubility of any substance whose anion is basic will be increased in solutions of low pH, as the basic anion reacts with the H+ in solution and is drawn out of the equilibrium. As the basic anion is consumed, the dissolution reaction is driven to the right by Le Chatelier's principle. Of the substances given as choices, Pb(OH)2 has the most basic anion, OH-. Thus it is most likely to show increased solubility in an HCl solution. Answer choice B is the best choice.
Which of the following describes the orbital geometry of an sp3 hybridized atom? Linear Trigonal planar Tetrahedral Octahedral
Answer Key: C Orbital geometry is also known as electron domain geometry. Hybridization is based on the number of electron domains surrounding an atom. An sp3-hybridized atom, such as C in CH4 or N in :NH3, mixes the s and p subshells (one s and three p orbitals) to form four equivalent orbitals. Four equivalent orbitals point at the vertices of a tetrahedron. Thus, C is the correct answer.
An object with 15 grams mass is immersed in benzene and suffers an apparent loss of mass of 5 grams. What is the approximate specific gravity of the object? (Data: Specific gravity of benzene = 0.7.) 1.4 1.8 2.1 3.0
Answer Key: C The buoyant force on an object immersed in a fluid is equal to the weight of the fluid displaced by the object (Archimedes' principle). There were 5 g of liquid displaced; thus, the ratio of object mass to fluid mass is 15/5 = 3. The specific gravity of the object (mass per unit volume compared with water) is three times the specific gravity of benzene (3 x 0.7 = 2.1) because the volumes of object and displaced liquid are equal.
Which of the following valence electron configurations corresponds to an atom in an excited state? 1s2 2s2 2s2 2p1 3s2 3d1 4s2 3d2
Answer Key: C The ground state electron configuration of an atom is generally written as follows: 1s22s22p63s23p64s23d104p65s2... with the orbital energetics following the (n + l) rule. When an electron is excited, it "jumps" to a higher energy subshell. Since the 3d subshell (n + l = 5) differs by more than one unit of (n + l) from the 3s subshell (n + l = 3) it is clear that the electron in the 3d subshell is in an "excited" state. Thus, C is the best answer.
How many molecules of NADH are produced from six molecules of glucose that undergo glycolysis? 3 6 12 18
Answer Key: C This is a Biochemistry question that falls under the content category "Principles of bioenergetics and fuel molecule metabolism." The answer is C because each cycle of glycolysis produces two NADH molecules and requires an input of one glucose molecule. This is a Scientific Reasoning and Problem Solving question because you must identify the appropriate formula to solve a problem in the context of glycolytic metabolism.
Regular breathing and regular, slow brain waves are most consistent with which stage of sleep? NREM1 NREM2 NREM3 REM
Answer Key: C This is a Psychology question that falls under content category "Making sense of the environment." The answer to this question is C because regular breathing and heart rate and slow brain waves are most consistent with deep sleep, NREM3. It is a Knowledge of Scientific Concept and Principles question because it requires knowing the properties of different stages of sleep.
Which concept describes the self-concept as a product of social interaction, emerging out of the way an individual perceives others to view him or her? The front stage self The back stage self The looking-glass self The self-fulfilling prophecy
Answer Key: C This is a Sociology question that falls under the content category "Self-identity." The answer to this question is option C, because the question provides the main features of the concept of the looking-glass self. In line with the symbolic interactionist paradigm in sociology, the looking-glass self suggests that the self-concept is more than just the product of self-reflection. Instead, the way in which people see themselves is based on how they believe others perceive them during social interactions. The question requires Knowledge of Scientific Concepts and Principles because you are asked to recognize the concept referenced in the question.
Social stigma is most commonly associated with: an unrecognized prejudice. a failure to cope with stress. an attribute that is devalued. a discriminatory reaction.
Answer Key: C This is a Sociology question that falls under the content category "Social thinking." The answer to this question is option C. Social stigma is derived from the symbolic interactionist perspective in sociology and calls attention to how certain individuals or groups face social disapproval. Often, the social disapproval is associated with a behavior, identity, or other attribute that is considered deviant by others. This question assesses Knowledge of Scientific Concepts and Principles because you are asked to select the option that identifies a specific concept.
A glass fiber carries a light digital signal long distances with a minimum loss of amplitude. What optical property of glass allows this phenomenon? Dispersion Refraction Reflection Diffraction
Answer Key: C. Light can be carried along a distance within a transparent material by means of total internal reflection. Thus, C is the best answer. Refraction would be a contributor to disruption of signal
The energy, E, of a hydrogen atom with its electron in the nth shell of a hydrogen atom is given by E = -C/n2 where n = 1,2,3, . . . and C is a positive constant. If an electron goes from the n = 2 shell to the n = 3 shell: A. a photon is emitted. B. an electron is emitted. C. an electron is absorbed. D. the energy of the atom is increased.
Answer Key: D According to the relation given in the passage, the energy of an electron in orbit n = 3 is less negative or greater than the energy in orbit n = 2. Thus energy is required to make the transition from n = 2 to n = 3 and the atom gains energy. Answer D states precisely this and only D is consistent with this result.
When a light wave and a sound wave pass from air to glass, what changes occur in their speeds? Both speed up. Both slow down. Light speeds up; sound slows down. Light slows down; sound speeds up.
Answer Key: D Light slows down because the index of refraction in the glass is greater than in the air. The index is a measure of the ratio of the velocity in air to the velocity in the medium. For sound the speed becomes greater because the speed of sound in a solid is much greater than in air (the glass has stiff rigid bonds which gives rise to a speed more than 10 times greater than in air).
Electric power for transmission over long distances is "stepped up" to a very high voltage in order: to produce currents of higher density. to produce higher currents in the transmission wires. to make less insulation necessary. to cut down the heat loss in the transmission wires.
Answer Key: D Power transmitted to a load at the user's end of an electrical line is the product of the current I times the voltage V at the user's end. The power company has the option of using a low voltage or a high voltage for a given amount of power delivered. Using Ohm's law (I = V/R), the power delivered can also be written as P = V2/R. The power lost in the transmission line is I2R. Since the resistance R is fixed by the material and dimensions of the line, we see that using a high voltage at a lower current maximizes the power to the user and minimizes the heat loss in the transmission line, choice D.
If the second floor and the top floor of a building are separated by a distance of 100 m, what is the approximate difference between the air pressures of the two levels? (Note: Air density = 1.2 kg/m3and gravitational acceleration = 10 m/s2. Neglect the compressibility of air.) 600 N/m2 800 N/m2 1000 N/m2 1200 N/m2
Answer Key: D Pressure is given by (density) • g • (height) if density does not change. This is approximately true for small atmospheric height differences, such as 100 m. The pressure difference will be given by (density) • g • (change in height) or (1.2)(10)(100) = 1200 N/m2. Thus, D is the best answer.
Which enzymatic kinetic parameter is NOT affected by the presence of an uncompetitive inhibitor? KM kcat Vmax KM/Vmax
Answer Key: D This Biochemistry question falls under the content category "Principles of chemical thermodynamics and kinetics." The answer is D because uncompetitive inhibitors affect both the kcatand KM of an enzymatically catalyzed reaction in a way that does not change the slope of the Lineweaver-Burk plot, which means the KM/Vmax is not changed.
A public health video designed to promote flu shots shows a physician from a prestigious institution delivering facts about how viruses spread. The video also features data on how viruses can expose the body to serious illnesses. The video uses all of the following variables to manipulate attitudes EXCEPT: the peripheral route to persuasion. the central route to persuasion. source characteristics. audience characteristics.
Answer Key: D This is a Psychology question that falls under content category "Attitude and behavior change." The answer to this question is D because the characteristics of the audience are not addressed in the stem. The video combines the central route to persuasion (disease) with the peripheral route (the prestige of the physician). The mention of the physician's affiliation with a prestigious institution is a manipulation of source characteristics. It is a Knowledge of Scientific Concepts and Principles question because it requires knowing the definitions of the terms listed in the response options.
A patient experiences a debilitating depressive episode after the loss of a job. A psychologist suggests that the patient had a genetic predisposition to depression and that unemployment acted as a trigger. The psychologist is using which approach to explain the patient's depression? Rogers's humanistic theory Beck's cognitive theory The opponent process model The diathesis-stress model
Answer Key: D This is a Psychology question that falls under content category "Individual influences on behavior." The answer to this question is D because the diathesis-stress model integrates the influence of biological predispositions and the environment. It is a Knowledge of Scientific Concepts and Principles question because it requires identifying that the therapist is using the diathesis-stress model.
A researcher interested in actor-observer bias asks a group of viewer participants to watch a target participant work on a series of puzzles. Which two variables is the researcher most likely to compare in this study? A. The viewers' memory for the puzzles and the target's memory for the puzzles B. The viewers' estimate of the difficulty of the puzzles and the target's estimate of the difficulty of the puzzles C. The viewers' likelihood of accurately remembering the target's performance and the target's likelihood of accurately remembering his or her own performance D. The viewers' likelihood of attributing the target's performance to intellect and the target's likelihood of attributing his or her own success to intellect
Answer Key: D This is a Psychology question that falls under content category "Social thinking." The answer is D because actor-observer bias refers to the actor's tendency to explain his/her own behavior by situational factors whereas the observer tends to explain the actor's behavior by internal stable traits. Thus, an appropriate measure would be to assess whether the actor and the observer attribute the actor's behavior to a relatively stable trait such as intellect. It is a Scientific Reasoning and Problem Solving question because it requires applying the definition of actor-observer bias to predicting the researcher's variables.
Which statement best reflects how sociologists differentiate the concepts of ethnicity and race? A. Ethnicity is both dynamic and self-chosen, whereas race is immutable. B. Ethnicity addresses shared attitudes, whereas race addresses collective norms. C. Ethnicity is tied to a geographic region, whereas race is tied to an identity. D. Ethnicity classifies by culture, whereas race classifies by physical characteristics.
Answer Key: D This is a Sociology question that falls under the content category "Demographic characteristics and processes." The answer to this question is D because it best reflects the sociological distinction between race and ethnicity. Sociologists consider ethnicity to be categorizations of people based on culture and ancestry. Sociologists consider race to be categorizations of people based on perceived physical characteristics. Both concepts are understood in sociology as complex, social categories that change over time, rather than simply biological features of human beings. It is a Knowledge of Scientific Concepts and Principles question because it requires you to distinguish between two similar, yet conceptually distinct, ideas from the social sciences.
When individual experiences cognitive dissonance, they are more likely to change... a. behavior b. attitude
B
The two primary factors that normally determine the level of blood pressure are: the blood concentration of L-NMMA and norepinephrine. the cardiac output and the resistance to blood flow. the blood volume and the amount of L-arginine in the diet. the heart rate (heartbeats/minute) and the cardiac stroke volume.
B (blood volume, and vasoconstriction/dilation....D may seem tempting but does not address circulation resistance)
The chemical valinomycin inserts into membranes and causes the movement of K+ into the mitochondria. If mitochondria are treated with valinomycin, the rate of ATP synthesis in the mitochondria will most likely: A. decrease, because the K+ will compete with protons at the active site on ATP synthetase. B. decrease, because movement of K+ into the mitochondrial compartments will disrupt proton movement into the intermembrane space. C. increase, because the net positive charge in the mitochondria will cause increased movement of protons into the intermembrane space. D. increase, because the additional positive charge will further activate ATP synthetase.
B Any disruption of mitochondria is likely to decrease ATP production since they are a major cellular source of that molecule --> A is wrong because K+ and protons are of very different size, unlikely to be competitive
Why do calcium supplements often include vitamin D? A. Vitamin D is needed to prevent rickets. B. The activated form of vitamin D stimulates the absorption of calcium into the blood. C. The activated form of vitamin D enhances the action of calcitonin. D. The activated form of vitamin D enhances the uptake of calcium by bone tissue.
B B/D are similar, but vitamin D acts on the small intestine and the bone...calcium must first be absorbed from diet before deposition can even be considered
If oligonucleotides such as mRNA were not degraded rapidly by intracellular agents, which of the following processes would be most affected? The production of tRNA in the nucleus The coordination of cell differentiation during development The diffusion of respiratory gases across the cell membrane The replication of DNA in the nucleus
B Destruction of mRNA prevents continuous protein production (since mRNA acts as a transcript), coordination of cell differentiation is very sensitive to protein/gene expressions and needs to be controlled tightly for proper processes
People who are born without sweat glands are likely to die of heat stroke in the tropics. This indicates that, under tropical conditions, the human body may: A. gain, rather than lose, heat by evaporation. B. gain, rather than lose, heat by radiation. C. need to use different mechanisms than in temperate zones to maintain body temperature. D. be better able to regulate body temperature than under temperate conditions.
B If people lack sweat glands, they are unable to make sweat nor to capitalize upon the evaporative cooling of sweat (A). These individuals are forced to rely nearly solely on vasodilation (radiation) for responding to elevated external temperatures. So they might die
In mammals, which of the following events occurs during mitosis but does NOT occur during meiosis I? Synapsis The splitting of centromeres The pairing of homologous chromosomes The breaking down of the nuclear membrane
B Splitting of centromeres only occurs during meiosis 2...tetrads are split during meiosis 1
The outer layers of human skin are composed of dead cells impregnated with keratin and oil, which make the epidermis relatively impermeable to water, yet humans sweat freely in hot temperatures. This occurs because: A. the salt in sweat allows it to diffuse through the skin. B. sweat glands have special channels through the skin. C. an osmotic gradient in sweat moves it through the skin. D. sweating occurs in only those areas of the body where the skin is water permeable.
B Sweat glands secrete into pores (typically hair follicle pores) which serve as bypass channels
Sarah noted that her skin blood vessels were usually constricted to conserve body heat in the cold environment of the mountains. However, her skin blood vessels would occasionally dilate for short periods of time. What would be the most probable physiological purpose for this periodic vasodilation? Maintain normal skin tone Maintain sufficient oxygenation of cells Reduce excessive blood pressure Maintain normal muscle tone
B While B/C may both seem logical, blood pressure in this case is regulated tonically...additionally the context of exercise gives further evidence for oxygenation needs
Postmenopausal women receiving estrogen and progesterone therapy will most likely experience which of the following side effects? Breast tissue will atrophy. Vaginal tissue will dry out. Periodic menstruation will resume. Lactation will be induced.
C Addition of menstral hormones can re-instate periodic menstration
Under what condition would the level of calcitonin tend to increase? When there is a dietary deficiency of calcium When there is a dietary deficiency of vitamin D When the level of calcium in the plasma is high When the level of parathyroid hormone is too low
C Calci-tone-it-down (functions to decrease calcium levels) Thus will be released when calcium in plasma is high
Which of the following characteristics clearly marks fungi as eukaryotes? They have cell walls. They contain ribosomes. They contain mitochondria. They exhibit sexual reproduction.
C Presence of membrane bound organelles is a definite differentiation between Eukaryota and prokaryota
Which of the following hormones is(are) directly required for spermatogenesis? I: Luteinizing hormone (LH) II: Follicle-stimulating hormone (FSH) III: Inhibin IV: Testosterone IV only I and IV only II and IV only I, II, and III only
C Sertoli cells support and nourish the spermatocytes and promote the process of spermatogenesis. Spermatogenesis would not occur without Sertoli cells. The two hormones that directly stimulate Sertoli cells are FSH and testosterone. Think of the sperm as the female follicle --> there is no male luteum
Soaps are chemically modified natural products that can be derived from all of the following EXCEPT: fatty acids. cholesterols. triacylglycerols. phospholipids.
Cholesterol All others are very similar structurally but cholesterol is isoprene-derived and more cyclic
Which of the following recombinant processes depends on the F factor plasmid? Transformation Transduction Conjugation Translocation
Conjugation Bacteria can exchange genes by three processes: conjugation, transformation and transduction Conjugation: production of special conjugation pilus and transfer of DNA through another bacterium (needs special genes --> F factor = fertility and is the name given to the fertilized plasmid Translocation is for chromosomes, and transformation/transduction do not require recombinant plasmids
Antidiuretic hormone (ADH) acts to decrease urine output by increasing the water permeability of the walls of: A. the glomerulus. B. Bowman's capsule. C. the loop of Henle. D. the distal tubule and collecting duct.
D
Increased vasoconstriction has an important role in which of the following situations? Causing the decrease in blood pressure associated with fainting Increasing blood flow to muscle during exercise Increasing blood flow to skin during blushing Maintaining blood pressure during a hemorrhage
D B and C describe vasodilation
After the gall bladder is removed from a patient, the patient will most likely have reduced ability to digest: protein. starch. sugar. fat.
D Bile salts stored by gall bladder
Production of which of the following hormones will be inhibited by the administration of dietary calcium to prevent osteoporosis? Growth hormone Calcitonin Thyroid hormone Parathyroid hormone
D Calcitone-it-down (lower blood plasma levels) Calci-try-to-raise (raise blood plasma) PTH (raise blood plasma by resportion from bone)
After Sarah's accident, her attending physician detected the protein myoglobin in her urine. What type of injury is consistent with this observation? I: Broken bone II: Damaged muscle III: Damaged kidney A: I only B: III only C: I and III only D: II and III only
D Kidney or muscle breakdown will result in myoglobin being released into the urine stream for excretion
Delayed ovulation, as a cause of tubal pregnancy, would most likely be associated with delayed secretion of which of the following hormones? Progesterone Estrogen HCG Luteinizing hormone
D LH is responsible for the trigger of ovulation (remember LH surge is vital for ovulation)
An effective and efficient method for the delivery of an antisense gene as part of gene therapy could be: orally as an emulsified product. microinjection into individual body cells. intravenously as a nonantigenic, blood-stable product. infection of an embryo by a virus modified to carry the gene.
D Needs to be able to become incorporated within the genome and cause all derived cells to carry the mutation
Inflation of the lungs in mammals is accomplished by: A. diffusion of gases. B. active transport of gases. C. positive pressure pumping action. D. negative pressure pumping action.
D Negative pressure is the vacuum fore created by diaphragm contraction, while positive pressure forces the air out of the lungs in exhalation.
The fundamental, resonant wavelength of a pipe open at both ends that is 1 m long and 0.1 m in diameter is: 0.1 m. 0.2 m. 1.0 m. 2.0 m.
D Resonant wave formulas --> L = 1/2 gamma
In eukaryotes, oxidative phosphorylation occurs in the mitochondrion. The analogous structure used by bacteria to carry out oxidative phosphorylation is the: cell wall. ribosome. nuclear membrane. plasma membrane.
D The enzymes for oxidative phosphorylation are embedded in the inner membrane.
A drug that increases the risk of a tubal pregnancy is most likely to inhibit which one of the following actions? A. Contraction of the uterus B. Secretion of follicle-stimulating hormone C. Onset of menstruation D. Transport of the ovum from ovary to uterus
D The main reason for the occurrence of ectopic pregnancies is the failure of the fertilized egg to be transported from the oviducts to the uterus. When the transport system fails, the embryo implants in the oviduct, rather than in the uterus.
The cell type in the male reproductive system that is most analogous to the female ovum is the: spermatogonium. primary spermatocyte. spermatid. spermatozoon.
D The mature ovum is the female gamete that has completed meiosis and contains the haploid number of maternally derived chromosomes. This makes it most analogous to spermatozoa, the mature male gametes that contain the haploid number of paternally derived chromosomes.
When a weak acid (HA) is titrated with sodium hydroxide in the presence of an indicator (HIn), the pH at which a color change is observed depends on the: final concentration of HA. final concentration of HIn. initial concentration of HA. pKa of HIn.
D The indicator will change color over a specific pH range. The range at which the color change takes place depends on the point at which HIn is converted to In-, and this depends on the pKaof the indicator which is answer D.
Which steps involved in the contraction of a skeletal muscle require binding and/or hydrolysis of ATP? I: Dissociation of myosin head from actin filament II: Attachment of myosin head to actin filament III: Conformational change that moves actin and myosin filaments relative to one another IV: Binding of troponin to actin filament V: Release of calcium from the sarcoplasmic reticulum VI: Reuptake of calcium into the sarcoplasm I, II, and III only II, III, and IV only I, III, and VI only III, IV, and VI only
I, III, VI I - ATP hydrolyzed which allows for dissociation III - Confirmational change energy given by ATP hydrolysis VI - reuptake stimulated by ATP active transport
Which concept refers to feelings of social disconnection that result from weak communal bonds and rapidly changing norms? Anomie Obedience Out-group Role exit
anomie
The ectoderm develops into all except nerves epidermis dermis
dermis = mesenchymal
A student plans to add HCl to a solution containing Pb(NO3)2(aq). To determine how much Pb2+ will precipitate from solution when the HCl is added, the student needs to know which of the following? Ka for HCl Ka for HNO3 Ksp for PbCl2 Keq for the reaction Pb2+ + 2 e- Pb
Ksp for PbCl2 To determine how much Pb2+ will precipitate, the student must know the solubility of PbCl2, which is related to the solubility product constant Ksp of PbCl2. Thus, C is the best answer.
The sodium pump would be most active in cells of which of the following structures? Veins Loop of Henle Lungs Bone marrow
Loop of Henle Na+ resorption is of upmost importance to the loop of henle --> primary function
Of the following tissues, which is NOT derived from embryonic mesoderm? Circulatory Bone Dermal Nerve
Nerve
Which participant in the electron transport chain has the greatest attraction for electrons? FAD NAD+ Oxygen Cytochrome c
Oxygen (think of the ETC as a cascade, the affinities must be increasingly higher as the cascade goes, thus the last acceptor - oxygen - must be the highest)
Which type of molecule is LEAST likely to be found in a eukaryotic cell membrane? Phospholipid Cholesterol Glycoprotein Peptidoglycan
Peptidoglycan remember this is only for bacteria!!
The transition of which amino acid from the interior of a soluble globular protein to the surface is associated with the largest positive ΔGº? Asp Phe Glu Ser
Phe - most hydrophobic so positive delta G will occur moving from the favorable interior to the less favorable exterior (exposed to water)
The terminal electron acceptor in the metabolic pathway responsible for the chemical changes observed when an anerobic muscle fiber was electrically stimulated is: pyruvate. oxygen. NAD+. water.
Pyruvate lactic acid fermentation provides the energy for the contractions that result from electrical stimulation. In this process, NADH reduces pyruvate to produce lactate. Therefore, pyruvate serves as the electron acceptor in production of lactate.
Researchers noted that in the absence of a reducing agent the elution time of a certain protein from a size-exclusion column decreased considerably relative to the elution time when the buffer contained a reducing agent. Which type of molecular interaction was responsible for this observation? Hydrophobic interactions Salt-bridge formation Hydrogen bonding Disulfide bonding
Reducing agents get rid of disulfide bonds --> can be helpful or a reason to not use them in order to minimize degredation of protein The answer is D because the presence of a disulfide bond between two subunits of a protein would cause the protein to have a different elution time on a size-exclusion column. The fact that reducing agents eliminate this interaction is more evidence that a disulfide bond was present.
All of the following occur during normal inspiration of air in mammals EXCEPT: elevation of the rib cage. relaxation of the diaphragm. reduction of pressure in the pleural cavity. contraction of the external intercostal rib muscles.
Relaxation of the diaphragm The diaphragm is actually contracted during inspiration
Cyanogen bromide cleaves peptide bonds by first undergoing nucleophilic attack by the side chain of a methionine residue. Which atom is the nucleophile in this reaction? Sulfur Carbon Oxygen Nitrogen
Remember structure of methionine which is names as the molecule doing the nucleophilic attack (only atom in the side chain which has available lone pairs)
Anxious about a nagging illness, a patient feels ignored by a doctor who is struggling to catch up with patient examinations on a very busy day. The doctor misinterprets the discomfort and agitation of the patient as hostility. Which sociological paradigm can best explain this scenario? Functionalism Conflict Theory Symbolic Interactionism Social Constructionism
Symbolic Interactionism Subjects are negotiating meanings behind interactions, the meaning of the behavior from the patient is misinterpreted by the doctor
Which amino acid has the highest isoelectric focusing point? Arg Lys Asn Gln
The answer is A because the isoelectric point of an amino acid is the highest for basic amino acids, and arginine and lysine are both basic amino acids. However, arginine has a higher isoelectric point because it is more basic. (memorization)
The side chain of which amino acid is most likely to form a hydrogen bond with the side chain of glutamate? Asp Ala Gln Val
The answer is C because in order to hydrogen bond with glutamate, an amino acid side chain must contain a hydrogen bond donor group to match with the glutamate acceptor. Glutamine has an NH2 group that can act in this way.
Specific activity is a measure of: A. the total units of an enzyme in a solution. B. the amount of substrate converted to product in one minute. C. the enzyme units per milligram of total protein in a solution. D. the concentration of enzyme that results in a particular rate of catalysis.
The answer is C because the activity is a measure of the amount of enzyme per milligram of total protein. This provides a measure of the purity of an enzymatic mixture.
A heterotrimeric protein consists of three subunits with molecular weights of 10 kDa, 40 kDa, and 100 kDa. The protein is denatured with 3 M urea and subjected to size-exclusion chromatography. Which solute is the last compound to elute from the column? The 10-kDa subunit The 40-kDa subunit The 100-kDa subunit The urea
The answer is D because a size-exclusion column allows larger molecules to pass more freely through the column matrix and hinders the passage of smaller molecules. Urea is this smallest solute and would be the last to elute.
Disruption of two disulfide bonds within a protein requires: 1 molecule of NAD+. 2 molecules of NAD+. 1 molecule of NADH. 2 molecules of NADH.
The answer is D because the reduction of a disulfide bond requires two electrons and each molecule of NADH can provide two electrons when reducing another compound. disulfide bonds can be reduced when in the presence of an oxidizing agent
Which of the following conclusions is correct regarding virion biology? Virions lack genetic material. Virions can synthesize proteins. Virions lack enzymes. Virions are obligate parasites.
Virions are obligate parasites Virions do not have the means to reproduce without host "machinery", and thus cannot survive non-parasitically --> obligate parasite
Approximately how many moles of Al3+ are reduced when 0.1 faraday of charge passes through a cell during the production of Al? (Note: Assume there is excess Al3+ available and that Al3+ is reduced to Al metal only.) 0.033 mol 0.050 mol 0.067 mol 0.10 mol
Answer Key: A A faraday is equal to one mole of electric charge. Because each aluminum ion gains 3 electrons, 0.1 faraday of charge will reduce 0.1/3 moles of aluminum, or 0.033 moles of aluminum.
In a nearsighted individual, the image of a distant object is focused: A. in front of the retina, requiring diverging lens correction. B. in front of the retina, requiring converging lens correction. C. behind the retina, requiring diverging lens correction. D. behind the retina, requiring converging lens correction.
Answer Key: A A nearsighted (myopic) person can focus on nearby objects but cannot clearly see objects far away. The nearsighted eye has a focal length that is shorter than it should be, so the rays from a distant object form a sharp image in front of the retina. This condition is corrected by glasses with a diverging lens. Choice A is the correct answer
Which event occurs when a G protein-coupled receptor is activated? The α subunit binds GTP. The α subunit binds GDP. The β subunit binds GTP. The β subunit binds GDP.
Answer Key: A The answer is A because the exchange of GDP for GTP in the α subunit is what accompanies G protein-coupled receptor activation. This is a Knowledge of Scientific Concepts and Principles question because you are asked to recognize a scientific concept.
The normal path of sperm movement from the male testis to the point of fertilization in the female is: epididymis, vas deferens, urethra, vagina, cervix, uterus, fallopian tube. epididymis, vas deferens, ureter, cervix, uterus, fallopian tube. epididymis, vas deferens, urethra, vagina, uterus, ovary. interstitial cells, epididymis, vas deferens, vagina, uterus, ovary.
Answer Key: A The question asks the examinee to identify the correct order of structures through which sperm cells travel from the male testis to the point of fertilization in the female. As sperm cells leave the testis they travel through the epididymis to the vas deferens and into the urethra. The sperm then enter the female's vagina, travel through the cervix and uterus, and enter the fallopian tube, where fertilization most commonly takes place. Of the options listed, only A correctly identifies both the structures and the order. Thus, A is the best answer.
A hiker becomes lost and has no drinking water for 2 days. At the end of this time, which of the following changes in hormone production would be expected to be significant in this individual? Decreased glucocorticoid secretion Decreased aldosterone secretion Increased insulin secretion Increased antidiuretic hormone secretion
Increased antidiuretic hormone secretion (want to retain as much water as possible)
