MCAT Practice Test #3

what are the 5 AA that are both ketogenic and glucogenic?

1. tryptophan, 2. threonine, 3. tyrosine, 4. isoleucine 5. phenylalanine

1-Methylcyclohexanol reacts with HBr to form 1-bromo-1-methylcyclohexane. The mechanism for this reaction is likely to be an: A. SN1 reaction. B. SN2 reaction. C. Nucleophilic addition. D. Addition-elimination.

A. Since no double bonds are formed or broken, this must be a substitution reaction (eliminate choices C and D). Since the hydroxyl in the starting material is on a tertiary carbon atom, the mechanism cannot occur by a bimolecular pathway (eliminate choice B.) The protonated OH group (under acidic conditions) will leave as water to yield a tertiary carbocation, which will be attacked by the bromide ion to give the product.

The standard potential for the reaction K+ + e- --> K(s) = -2.93 V, as referenced against 2H+ + 2e- --> arrow H2(set to 0.0 V by definition). If solid potassium is placed into an aqueous solution of HCl, then: A. H2(g) and KCl(aq) are produced. B. Cl2(g) and KCl(aq) are produced. C. Cl2(g), H2(g), and KCl(aq) are produced. D. no reaction occurs.

A. Since the reduction of K+ as given in the question has a potential more negative than the reduction of H+, the oxidation of K(s) to K+ with transfer of electrons to H+ will have a positive potential and be spontaneous. This eliminates choice D. Hydrochloric acid (HCl, a strong acid) will dissociate nearly completely in water into H+ and Cl-. In the presence of a reducing agent (K), H+ ions can accept electrons and be reduced to H2, and K+ and Cl- will remain in solution. Since there is no oxidant which can accept the extra electron from Cl-, Cl2 will not be formed, eliminating choices B and C.

In which of the following are the acrosomal enzymes synthesized? A. Rough endoplasmic reticulum B. Cytoplasm C. Golgi apparatus D. The nucleus, since sperm have no cytoplasm

A. Acrosomal enzymes are located inside a membrane-bound vesicle and are going to be secreted. It is likely that they are processed through the secretory pathway, and to do so they must be synthesized in the rough ER (choice A is correct), not the cytoplasm (choice B is wrong). Proteins are never synthesized in the Golgi (choice C is wrong). It is true that sperm have very little cytoplasm, but during spermatogenesis they did originally have all normal cell structures. Also, protein synthesis never occurs in the nucleus (choice D is wrong).

(+)-Ginkgolide B is a diterpenoid trilactone with six five-membered rings, and is extracted from the root bark and leaves of the Ginkgo biloba tree. This molecule has blood-brain barrier permeability, the molecular formula C20H24O10 and a molecular weight of 424.4 g/mol. This molecule must contain: A. four isoprene units, additional functional groups and is able to perform simple diffusion through endothelial cells connected by tight junctions. B. four isoprene units, no additional functional groups and is able to perform simple diffusion through endothelial cells connected by tight junctions. C. four terpene units, additional functional groups and is able to perform simple diffusion through neurons connected by tight junctions. D. four isoprene units, additional functional groups and is able to perform simple diffusion through endothelial cells connected by gap junctions

A. Diterpenoids contain four isoprene units (eliminate choice C) and additional functional groups (eliminate choice B). The blood-brain barrier is a highly selective permeability barrier that separates the circulating blood from the central nervous system. It is formed by endothelial cells (another reason to eliminate choice C), which are connected by tight junctions (eliminate choice D). Choice A is correct because it accurately describes the composition of the molecule.

In humans, the fusion of the plasma membranes of a sperm and an ovum is followed first by which of the following? A. Release of the second polar body from the fertilized ovum B. Implantation in the uterus C. The first cell division of the zygote D. Gastrulation

A. Human ova do not complete the second meiotic cell division, including the formation of the second polar body, until after fertilization (choice A is correct). This process occurs immediately after fertilization and is a prerequisite for the first cell division of the zygote (choice C is wrong). Implantation happens a few days later, and gastrulation occurs at a stage many cell divisions after the first cell division (choices B and D are wrong).

Which of the following statements is true regarding self-schemata? Self-schemata contain information about one's experiences Self-schemata can be activated even when one is unconscious Self-schemata are not influenced by culture A. I only B. III only C. I and II only D. I and III only

A. Item I is true: according to the passage, self-schemata contain information about one's experiences (choice B can be eliminated). Item II is false: self-schemata are cognitive structures, which implies that one must be conscious in order to access them (choice C can be eliminated). Item III is false: according to the passage, self-schemata are influenced by culture (choice D can be eliminated and choice A is correct).

Object permanence allows human beings to realize that an object continues to exist outside of their perception of it. During which of Jean Piaget's stages does this ability develop? A. Sensorimotor B. Preoperational C. Concrete operational D. Formal operational

A. Object permanence develops during Piaget's first stage, the sensorimotor stage (choice A is correct). During all of the subsequent stages, according to Piaget's theory of cognitive development, children are using the object permanence skill that they previously developed. During the preoperational stage, children think more symbolically as they develop memory and imagination (choice B is wrong). Next is the concrete operational stage, when children begin to exhibit logical reasoning (choice C is wrong). This is followed by Piaget's final stage, that of formal operations, when children are able to consider abstract relationships and concepts (choice D is wrong).

Intercalator1 causes mutations in DNA by: A. inserting itself between base pairs. B. covalently modifying nucleotides. C. causing the formation of pyrimidine dimers. D. causing the formation of double stranded breaks.

A. The passage states that Intercalator1 is an intercalating agent; this means it inserts itself between base pairs in DNA (choice A is correct). While choices B, C and D are methods by which mutagens may damage DNA, they are not the method listed for Intercalator1.

Which of the following inhibitors would have no effect on the slope of a Lineweaver-Burk plot? A. Competitive Inhibitor B. Uncompetitive Inhibitor C. Noncompetitive Inhibitor D. Mixed Inhibitor

B. As the slope of the Lineweaver-Burk plot is Km/Vmax, the correct answer is an inhibitor that has the same effect on both Km and Vmax. An uncompetitive inhibitor leads to an equal decrease in the both the Km and Vmax, leading to a series of parallel lines on a Lineweaver-Burk plot (choice B is correct). Competitive, noncompetitive, and mixed inhibitions would all affect the slope of a Lineweaver-Burk plot (choices A, C, and D are wrong).

Increased intermolecular attractions cause the ratio PV/(RT) to decline because individual molecules: A. eventually combine with other molecules, decreasing the number of particles in the container. B. lose kinetic energy to potential energy and strike the side of the container with less force. C. increase in speed due to electron repulsion and strike the side of the container with increased force. D. transfer electrons during collisions with other molecules in the container.

B. Intermolecular attractions increase the potential energy between molecules, decreasing their kinetic energy. Note that the molecules do not undergo any reactions, eliminating choices A and D. Choice C is incorrect because intermolecular attractions do not result in electron repulsion.

Which of the following methods should be used to purify the mesylate mixture produced from Reaction 1 from any remaining starting material? A. NMR spectroscopy B. HPLC C. Thin-layer chromatography D. Size-exclusion chromatography

B. NMR spectroscopy is not a separation technique (eliminate choice A). Although size-exclusion chromatography is a separation technique that will allow for quantitative purification of mixtures, the differences in size of the compounds in the mesylate mixture are not significant enough for the technique to be efficient (eliminate choice D). Thin-layer chromatography (TLC) is also a separation technique, but it uses very small amounts of material to determine polarity of compounds and monitor reactions. It is not a technique that will allow for quantitative purification of a reaction mixture (eliminate choice C). HPLC (choice B) is the best choice as this form of chromatography would easily quantitatively purify a mesylate from its parent alcohol based on the difference in polarities of these functional groups.

Can glucogenic amino acids be converted into glucose? A. Yes: pyruvate and oxaloacetate can be converted directly into glyceraldehyde-3-P, which is a major intermediate in both gluconeogenesis and glycolysis. B. Yes: pyruvate and Krebs cycle intermediates can be converted into oxaloacetate, then phosphoenolpyruvate, which can enter gluconeogenesis. C. No: pyruvate and Krebs cycle intermediates are formed as part of glucose breakdown and this process is important to generate ATP for the cell. D. No: glucose is obtained from the diet and stored in the liver; it cannot be made as a new molecule because cellular respiration has several steps with a -ΔG.

B. This is a typical two by two question. The passage says that glucogenic amino acids are broken down into citric acid cycle intermediates or pyruvate. The Krebs cycle regenerates oxaloacetate (OAA), and in the first step of gluconeogenesis, pyruvate is also converted into OAA (by the enzyme pyruvate carboxylase). OAA is converted into phosphoenolpyruvate (PEP) by the enzyme phosphoenolpyruvate carboxykinase (or PEPCK). Gluconeogenesis can then continue to run, and will generate glucose from these non-carbohydrate precursor molecules (choice B is correct). Although glyceraldehyde-3-P is a major intermediate in both gluconeogenesis and glycolysis, pyruvate and oxaloacetate cannot be converted directly into this molecule (choice A is incorrect). Both choices C and D are incorrect because they start with "No"; as discussed above, glucogenic amino acids can be converted into glucose (choices C and D are wrong).

All of the following are involved in proprioception, EXCEPT: A. muscle spindles. B. baroreceptors. C. Golgi tendon organs. D. joint capsule receptors.

B. Baroreceptors are a type of mechanoroceptor located within the blood vessels sensitive to the stretch of the vessel itself. Baroreceptors detect changes in blood pressure, and are not involved in proprioception (choice B is correct). Muscle spindles are mechanoreceptors sensitive to the stretch of muscles, and are thus involved in movement and proprioception (choice A is wrong). Similarly, the Golgi tendon organs monitor the amount of tension in the tendons and are also involved in movement and proprioception (choice C is wrong). Joint capsule receptors sense pressure, movement, and tension in the joints and are also involved in movement and proprioception (choice D is wrong).

If the shin-byung syndrome is seen to occur across several generations of families who tend to live very close to one another, often in the same house, which of the following would be the best non-genetic reason for the generational repetition? A. Deindividuation B. Observational learning C. Group polarization D. Internal attribution

B. Barring a genetic or proximal environmental cause that would impact the entire family, it is most likely that children observe the behaviors and symptoms of the women afflicted with shin-byung in their family and replicate those behaviors themselves. This reflects the process of observational learning as described by Albert Bandura (choice B is correct). Deindividuation occurs when people lose their sense of self when they are part of a large crowd and are thus made to feel more anonymous. This can lead to irrational and mob-like behaviors (choice A is wrong). Group polarization is the process by which a person's initial attitude on a controversial topic can become more extreme by being part of a group of like-minded people (choice C is wrong). Making an internal attribution means that, when witnessing the behavior of another person, the observer decides that the cause of that person's behavior was internal rather than situational (choice D is wrong).

Which of the following equilibria could be present in a buffered solution? A. HCl( aq ) --> H + ( aq ) + Cl - ( aq ) B. H2CO3 (aq) --> H+(aq) + HCO3- (aq) C.H2O2(aq) + 2KI(aq)-->2KOH(aq) + I2 (aq) D. CaCl 2 ( aq ) --> Ca 2+(aq) + 2Cl- (aq)

B. Buffered solutions are commonly made with weak acids and their conjugate bases. The only weak acid given is carbonic acid (choice B). HCl (choice A) is a strong acid and CaCl 2 (choice D) is a salt. Choice C is a redox reaction.

PDC deficiency is a rare genetic disease. Which of the following conditions would be expected in patients with the disease? A. Metabolic alkalosis B. Lactic acidosis C. Hyperglycemia D. Hypolipidemia

B. In PDC deficiency, the pyruvate cannot be converted to acetyl-CoA and therefore, the cells can only undergo glycolysis and anaerobic respiration. The end product of anaerobic respiration in humans is lactic acid. Thus, patients with PDC deficiency have lactic acidosis (choice B is correct). Glucose is still being utilized for energy so there is no reason to assume its circulating levels would increase (eliminate choice C) and PDC does not play a role in processing lipids (eliminate choice D). A lack of PDC activity would not increase the body's pH (eliminate choice A).

In transposition of the great arteries, a congenital birth defect, the aorta of the newborn is connected to the right ventricle and the pulmonary artery is attached to the left ventricle. This would result after birth in circulation of: A. oxygenated blood through the systemic vasculature and deoxygenated blood through the pulmonary vasculature. B. deoxygenated blood through the systemic vasculature and oxygenated blood through the pulmonary vasculature. C. oxygenated blood through both the systemic and pulmonary vasculature. D. deoxygenated blood through both the systemic and pulmonary vasculature.

B. In the normal circulation, the right ventricle pumps blood through the pulmonary artery to the lungs. Blood returns from the lungs to the left atrium and is pumped by the left ventricle through the aorta to the rest of the body. If blood from the left ventricle passes to the pulmonary artery instead of the aorta and is then returned to the left atrium, oxygenated blood will loop around through the pulmonary system without passing to the rest of the body. At the same time, the deoxygenated blood from the systemic circulation will pass to the right atrium, then back out to the systemic circulation through the aorta rather than the pulmonary artery, causing deoxygenated blood to loop through this system (choice B is correct and choice A is wrong). Choices C and D are wrong since they have all blood either oxygenated or deoxygenated.

Muscle fibers are composed of small contractile units called sarcomeres. During contraction, which of the following occurs within a sarcomere? Myosin filaments shorten. Actin filaments shorten. Overlap between actin and myosin filaments increases. A. I only B. III only C. II and III only D. I, II, and III

B. Items I and II are false: During contraction, neither myosin nor actin filaments get shorter. The overlap between them increases to make the sarcomere shorter (eliminate choices A, C and D). Item III is true: The overlap between the fibers increases as part of contraction.

A semipermeable membrane separates an aqueous solution of 0.003 MNaCl from an aqueous solution of 0.0025 MBaF2. With this apparatus, one would observe that water crosses the membrane: A. from the BaF 2 solution to dilute the NaCl solution. B. from the NaCl solution to dilute the BaF 2 solution. C. from the BaF 2 solution to concentrate the NaCl solution. D. from the NaCl solution to concentrate the BaF 2 solution

B. Osmotic pressure is a colligative property, which means it depends only on the concentration of solute particles, and not their identity. Therefore, a 0.003 M solution of NaCl will have an effective molality of 0.006 M (since NaCl is composed of two ions) and a 0.0025 M solution of BaF2 will have an effective molality of 0.0075 M (since BaF2 is composed of three ions). Osmotic pressure will drive movement of water from the lower concentration solution (NaCl) to the higher concentration solution (BaF2). Note that this movement of water acts to dilute the BaF2 solution.

According to self-determination theory, which proposes that people will seek autonomy, competence, and relatedness throughout their lifespans, the oldest participants in the study would most likely: A. determine on their own that they are unfit to drive, regardless of their objective driving performances. B. emphasize that any decisions to limit their respective driving privileges are self-endorsed. C. strive to achieve a sense of acceptance regarding their individual life histories. D. enhance their driving skills at the expense of social relationships.

B. Self-determination theory maintains that, throughout the lifespan and especially in older age, people seek autonomy, competence, and relatedness. Autonomy refers to viewing one's circumstances as self-endorsed, while competence refers to the expression of one's talents. Finally, relatedness refers to a sense of being cared about by other people. Therefore, according to this theory, one of the oldest participants in this study would emphasize that a decision to limit his or her driving is self-endorsed (choice B is correct). A determination of being unfit irrespective of driving skill is not implied by self-determination theory (choice A is wrong). Enhancing one's skills at the expense of social relationships contradicts the theory's principle of relatedness (choice D is wrong). Finally, achieving a sense of acceptance of one's personal life history is associated with Erikson's developmental conflict of integrity versus despair, not with self-determination theory (choice C is wrong).

Which of the following is the LEAST characteristic of the Krebs cycle? A. Oxaloacetate is combined with acetyl-coA to produce citrate. B. Most of the energy is produced through substrate-level phosphorylation. C. Most of the energy is produced indirectly through high-energy electron carriers. D. 6 NADH, 2 FADH2, and 2 GTP are produced per glucose.

B. Since the question is looking for the item that is LEAST characteristic of Krebs cycle, eliminate choices that DO characterize it. Choice A is true and can be eliminated: oxaloacetate is combined with acetyl-CoA to form citrate (thus why the cycle is sometimes referred to as the citric acid cycle). Choice C is also true and can be eliminated: most of the energy is produced from the production of high-energy electron carriers (NADH and FADH2). Approximately 18 of the 20 ATP that are associated with Krebs are from these high-energy electron carriers (after they are oxidized in the electron transport chain). Choice D is also true and can be eliminated: six NADH, two FADH2, and two GTP are produced in the Krebs cycle per glucose. Choice B is the only false statement (which is the correct answer for this question). Only two of the 20 ATP made from the Krebs cycle are from substrate-level phosphorylation.

Which of the following is LEAST likely to lead to social loafing? A. Lack of individual evaluation B. Working in cohesive groups C. Incommensurate compensation D. Submaximal goal setting

B. Social loafing is a phenomenon whereby individuals exert less effort on a task when working in a group than they would if working alone. However, if the group is a cohesive unit, individuals are more likely to be concerned about the outcomes. This is especially true of in-groups, in which the members identify with one another and are more likely to make an effort to ensure that they meet the expectations of their fellow members (choice B is correct). If group members are not being evaluated on an individual basis, they tend to feel less accountable for their work. For example, if a group of five medical students were to receive a single grade for a project, each would likely feel less compelled to contribute than he or she would if group members were receiving individual grades (choice A is wrong). If group members are not receiving the same level of compensation, their efforts will likely reflect such disparity. For instance, if one team member is receiving $5 for her efforts, she will probably minimize those efforts if she knows other participants are receiving higher payouts (choice C is wrong). Submaximal goal setting occurs when group members decrease their efforts because they do not believe that they have to work as hard when others are working with them towards the same goal (choice D is wrong).

Stearic acid (or octadecanoic acid) is a saturated fatty acid with the formula CH3(CH2)16COOH After undergoing β-oxidation, it will generate: A. 9 acetyl-CoA, 9 NADH and 9 FADH2. B. 9 acetyl-CoA, 8 NADH and 8 FADH2. C. 8 acetyl-CoA, 8 NADH and 8 FADH2. D. 8 acetyl-CoA, 7 NADH and 7 FADH2.

B. Stearic acid has 18 carbons and so will undergo 8 rounds of β-oxidation. This will generate 9 molecules of acetyl-CoA (eliminate choices C and D), 8 molecules of NADH and 8 molecules of FADH2 (choice B is correct, eliminate choice A).

After asking the opinions of several medical students about raising the voting age, a researcher then asked those participants who were against such a proposal to write a brief essay in support of raising the voting age. As an incentive, he paid half of the medical students $1 and the other half $50. Next, he reassessed their opinions on the topic to see if writing the essay had made an impact. Which group was more likely to change opinions? A. Students paid $50 were more likely to change their opinions because of the conditioning. B. Students paid $1 were more likely to change their opinions because of cognitive dissonance. C. The two groups of students were equally likely to change opinions as the result of exposure to new information. D. No students would change their opinions because this was not a personal topic.

B. Students who are paid to advocate a given position are more likely to support that position when asked about their opinions if the incentive received was minimal, as they are more likely to attribute their opinion change to internal reasons rather than to an external circumstance (i.e., the compensation). Thus, cognitive dissonance causes a shift in opinion (choice B is correct). With respect to answer choice A, when students are given a substantial incentive (in this case $50) to advocate a conflicting position they are able to attribute their advocacy to the large reward given, rather than to internal factors; the pressure of cognitive dissonance is thus removed. Moreover, neither classical nor operant conditioning principles apply to this scenario. Classical conditioning requires the pairing of a neutral stimulus with an unconditioned stimulus until the two stimuli become associated, which is not pertinent to this situation. Operant conditioning involves increasing or decreasing the frequency of a certain behavior by repeatedly rewarding or punishing it, respectively, which did not occur in this case (choice A is wrong). There would be a greater cognitive dissonance effect on students without the external motivation to modify their positions (the group paid $1) than on those with an external explanation for the change (those paid $50). Moreoever, no new information was provided (choice C is wrong). The personal nature of the topic would not be relevant; so long as the students did not have an external factor to which to attribute their advocacy, they would experience cognitive dissonance and would be less supportive of their previous positions (choice D is wrong).

Which of the following best describes how the brain determines the location of a sound? A. The angle of the sound wave, with respect to the eardrum, allows the brain to determine the location of the sound. B. Sound waves reach the ear closest to the source of the sound first, and this difference in timing allows the brain to determine the location of the sound. C. The angle of the sound wave, with respect to the auditory hair cells, allows the brain to determine the location of the sound. D. Sound waves closer to the source have a higher frequency, and this difference in frequency allows the brain to determine the location of the sound.

B. The angle of the sound wave with respect to the ear is not pertinent to determining the location of the sound (choices A and C can be eliminated). Sound waves reach the ear closest to the source of the sound first, and the further ear second. This time gap allows the brain to determine the location of the sound (choice B is correct). Choice D is incorrect; the frequency of the sound is not relevant to determining the location, nor is there a difference from one ear to the next.

DNA from resistant bacteria in Dish 6 is extracted and placed on agar with phage-sensitive E. coli. After incubation it is determined that these E. coli are now insensitive to phage T1 infection. The most likely mechanism for their acquisition of resistance is: A. transduction. B. transformation. C. sexual reproduction. D. conjugation.

B. The definition of transformation is the process in which naked DNA, not a virus, is taken into a cell and changes the genetic characteristics of that cell. That is the case in this experiment, with extracted DNA making cells resistant to the virus (choice B is correct). Transduction is mediated by a virus, conjugation involves direct transfer of DNA between bacteria, and sexual reproduction does not apply to bacteria (choices A, C, and D are wrong).

Fetal circulation differs from adult circulation in many ways. One of the main differences is that in the former: A. fetal hemoglobin has lower O2 affinity than does maternal hemoglobin. B. a pathway exists for blood to circumvent the lungs. C. blood flows through the systemic vascular system only. D. the ductus arteriosus carries oxygenated blood, while in the adult it carries deoxygenated blood.

B. The passage states that fetal hemoglobin has a higher affinity for oxygen (choice A is wrong) and that there is some blood flow through the pulmonary circuit (choice C is wrong). The ductus arteriosus does carry oxygenated blood in the fetus but closes shortly after birth so that this vessel is not present in adults (choice D is wrong). The purpose of the ductus arteriosus is to help shunt blood past the inactive fetal lungs (choice B is correct).

E. coli is a generally harmless bacterium, often used for research purposes. Some strains of E. coli live mutualistically inside human digestive tracts. Sometimes these bacteria can cause infection outside the iinfection outside the intestinal tract, most notably in the urinary tract, the biliary tract, and the nervous system. In which of the following structures is E. coli most likely to cause infection? A. Trachea B. Bladder C. Small intestine D. Large intestine

B. The question states that E. coli can cause disease outside of the intestinal tract (choices C and D are wrong), in the urinary tract, the biliary tract, and the nervous system. The bladder is the best answer since this is part of the urinary tract (choice B is correct), which was mentioned as a potential site of infection while the respiratory system, and thus the trachea, was not (eliminate choice A).

A person sees a small grassy area containing flowers outside of a residential building. This person's brain draws on various memories of gardens and the scents of flowers and grass in order to interpret that this grassy area is a garden. This is an example of: A. bottom-up processing. B. top-down processing. C. superimposition. D. contextual reception

B. Top-down processing is a Gestalt psychology term for interpreting sensory stimuli based on experience and larger contextual information in order to slowly work down and figure out the precise nature of each stimulus (choice B is correct). Bottom-up processing is the Gestalt term for the reverse process, by which one starts with a small sensory stimulus and integrates progressively more contextual information in order to determine its nature (choice A is wrong). Superimposition is a process whereby one stimulus is layered on top of another (choice C is wrong). Contextual reception is simply another way of saying that one is receiving contextual stimuli, not necessarily even processing it (choice D is wrong).

At physiological pH, the amino acid with the formula C4H7NO4 has: A. two deprotonated carboxylic acid groups and is ketogenic. B. one deprotonated carboxylic acid group and is ketogenic. C. two deprotonated carboxylic acid groups and is glucogenic. D. one deprotonated carboxylic acid group and is glucogenic

C At physiological pH (about 7.4), both the carboxylic acid end of the amino acid and the side chain COOH will be deprotonated. This is because physiological pH is above the pKa values for these acidic protons (carboxyl pKa is approximately 2, and the R-group pKa is approximately 4). Thus, aspartic acid will actually be in its aspartate form, and will have two deprotonated carboxylic acid groups at physiological pH (choice C is correct and choice D is wrong).

Which personality disorder describes someone who has a history of unstable relationships, a diffuse and unreliable sense of identity, chronic feelings of emptiness, and a history of suicidal thoughts and gestures? A. Schizotypal personality disorder B. Dependent personality disorder C. Borderline personality disorder D. Antisocial personality disorder

C The personality disorder characterized by unstable identity and interpersonal relationships, as well as by chronic feelings of emptiness and a history of suicidality, is borderline personality disorder (choice C is correct). Schizotypal personality disorder is characterized by odd or eccentric behavior and acute discomfort in interpersonal relationships, to the point that people with this disorder rarely have social ties outside of immediate family members. Schizotypal individuals also frequently have notable cognitive or perceptual disturbances (choice A is wrong). Dependent personality disorder is characterized by difficulty in making everyday decisions, a need for advice and reassurance from others, reluctance to disagree with others out of a fear of loss of approval or support, feelings of helplessness or discomfort when alone, and an unrealistic preoccupation with fears of abandonment. Additionally, people with this disorder have difficulty initiating projects and go to extraordinary lengths to obtain nurturance and support (choice B is wrong). Antisocial personality disorder is characterized by a pervasive pattern of indifference to, and violation of, the rights of others; this pattern can be seen through repetitive rule-breaking and failure to conform to social norms, failure to plan ahead, impulsivity, irritability and aggressiveness, irresponsibility, and a lack of remorse. People with this disorder do not have an unstable sense of identity, nor do they generally contemplate suicide without extreme provocation (choice D is wrong).

In a facultative anaerobe, which of the following processes occurs under both aerobic and anaerobic conditions? A. Fermentation B. Krebs cycle C. Glycolysis D. Oxidative phosphorylation

C. A facultative anaerobe can survive through fermentation when oxygen is not available but will use oxidative respiration when oxygen is available. Glycolysis will occur under both aerobic conditions (in which case the pyruvate will go on to enter the Krebs cycle as acetyl-CoA) and under anaerobic conditions (fermentation reduces pyruvate to alcohol or lactate), so choice C is correct. Fermentation occurs only in anaerobic conditions (choice A is wrong), while the Krebs cycle and oxidative phosphorylation can occur only in aerobic conditions (choices B and D are wrong).

An object is floating in a fluid of 1.5 specific gravity. If the volume of the fluid displaced by the floating object is 5 × 10-3 m3, what is the object's mass? A. 2.5 kg B. 5.0 kg C. 7.5 kg D. Cannot be determined from the information given

C. Because the object is floating, the object's weight is balanced by the buoyant force; that is, mg = ρfluidVsubg, or, after canceling the g's, m = ρfluidVsub. With ρfluid = 1.5ρH2O = 1500 kg/m3 and Vsub = 5 × 10-3 m3, we find that m = ρfluidVsub = (1500 kg/m3)(5 × 10-3 m3) = 7.5 kg

Which of the following is NOT true regarding somnambulism (sleepwalking), a type of parasomnia? A. Sleepwalking tends to occur during slow-wave sleep B. Typically individuals will engage in sleepwalking during the first third of the night C. Individuals will often act out the dreams they are concurrently having while sleepwalking D. While somnambulism tends to affect many children, most will grow out of it by adulthood

C. Somnambulism, or sleepwalking, occurs during slow-wave non-REM sleep (choice A is wrong), typically during the first third of the night (which corresponds to the fact that more slow-wave, deep sleep occurs early in the night; choice B is wrong); therefore, since it occurs during non-REM sleep, it is not possible for sleepwalkers to be concurrently dreaming (which only occurs during REM sleep), so sleepwalkers cannot be acting out the dreams they are having (choice C is correct). Somnambulism is common in children and studies suggest that up to 20-25% of all children have experienced at least one sleepwalking episode. Sleepwalking usually disappears by adolescence (choice D is wrong).

Researchers found that people with graduate or professional degrees were divorced less often than were those with other levels of education. Therefore, it is possible that the success of a marriage depends on: A. economic capital. B. political capital. C. cultural capital. D. social capital.

C. According to social reproduction theory, inequality is transmitted from one generation to the next through various forms of "capital". Education is a classic example of cultural capital, which includes non-financial social assets such as knowledge, skills, and experience (choice C is correct). Education may be related to economic and political success; however, this is not supported by the information provided (choices A and B are wrong). The other choice, social capital, is also an important mechanism of social reproduction. It includes relationship-based social assets, like influence and "connections" with people in one's social network (choice D is wrong). It is important to note that the question stem states that cultural capital "might" determine marital success, as correlation does not necessarily imply causation.

Decreased secretion of aldosterone has all of the following effects EXCEPT: A. increased loss of Na + in urine. B. decrease in extracellular fluid volume. C. increase in arterial pressure. D. increase in urine volume

C. Aldosterone causes increased sodium reabsorption, and because of the rise in systemic Na+, there will be decreased water loss, increased extracellular fluid volume and increased blood pressure. Decreased secretion of aldosterone would cause the opposite: increased loss of sodium (choice A is true and eliminated), a decrease in the extracellular fluid volume (choice B is true and eliminated), and an increase in urine volume (choice D is true and eliminated). It will not cause an increase in blood pressure, however, since more urine is formed and extracellular fluid volume lost (choice C is false and thus the correct answer choice).

Eukaryotic cells use reciprocal regulation to make sure β-oxidation and fatty acid biosynthesis do not occur at the same time. This is accomplished by malonyl CoA, which inhibits the carnitine shuttle required to transfer activated fatty acids from the cytoplasm to the mitochondrial matrix. Each of the following is a true statement EXCEPT: A. both β-oxidation and fatty acid biosynthesis occur in four steps; fatty acid biosynthesis involves elongation, two redox reactions and a dehydration. B. β-oxidation involves the reduction of both FAD and NAD+; fatty acid biosynthesis oxidizes two NADPH (generated by the pentose phosphate pathway) to two NADP+. C. because of this reciprocal regulation, both β-oxidation and fatty acid biosynthesis occur in the mitochondrial matrix. D. β-oxidation generates acetyl CoA, while fatty acid biosynthesis uses malonyl CoA, which is made from acetyl CoA by acetyl CoA carboxylase.

C. Choices A, B and D are true statements. Choice C is false (and the correct answer); β-oxidation occurs in the mitochondrial matrix and fatty acid biosynthesis occurs in the cytoplasm.

If one woman in a small and isolated Korean village fell ill with shin-byung, and then her close friend also began experiencing similar symptoms, claiming that she too was being pursued by spirits, which of the following might explain this occurrence regarding the friend? A. Compliance followed by obedience B. Conformity followed by compliance C. Conformity followed by private acceptance D. Obedience followed by conformity

C. Conformity, obedience, and compliance are related but distinct terms. Conformity involves changing one's behavior in order to fit in with the norms of a particular social group, most typically a group that has a certain level of social importance. Obedience involves changing one's behavior in response to the direct command or order of a person who is in authority or is of higher social status. Compliance involves changing one's behavior in response to a request from another person who is of equal or lower status (thus differing from obedience). Private acceptance is an attitude change that can occur in a person due to the social influence of others. Thus, it is most likely that the friend first conformed to the behavior of the woman initially affected by shin-byung symptoms, then privately accepted the possibility of spirit possession after modifying her behavior (choice C is correct). One could comply with a request from a peer and then obey a command from a leader, but that would not explain the situation described (choice A is wrong). Similarly, changing one's behavior in accordance with a group norm and then responding to a request from a peer would not fit the described situation either (choice B is wrong). Finally, following the orders of an authority figure and then the norms of a desired social group would not explain the shin-byung symptoms in this scenario (choice D is wrong).

Which of the following processes do NOT occur at the placenta? Diffusion of amino acids from fetal blood to maternal blood Mixing of maternal and fetal blood and gas exchange Exchange of CO2 and O2 between fetal and maternal blood A. I only B. II only C. I and II only D. I and III only

C. Item I does not occur: Amino acids are charged and cannot cross the placental and fetal capillary membranes (eliminate choice B). Item II does not occur: Fetal and maternal blood do not mix, so the only way substances can cross the placental barrier is if they are lipid soluble or if they are actively transported (eliminate choice A and D). Item III is correct: CO2 and O2 are lipid soluble and easily cross the barrier (choice C is correct).

Measurements of which of the following would be sufficient to calculate the usable work performed by a mechanical engine? A. The rate at which energy is consumed by the engine and the amount of time the engine was running B. The heat produced by the engine and the amount of time the engine was running C. The power output of the engine and the amount of time the engine was running D. The energy consumed by the engine and the amount of time the engine was running

C. Power is defined as work divided by time: P = W / t. Therefore, if the power output P and the time t are known, the work performed can be calculated by the equation W = Pt. Since we want the usable work produced by the engine, which presumably is not 100% efficient, the output power is needed, which will be less than the input power.

Which of the following would be the most effective method to determine if transcription of a gene had been silenced? A. DNA fingerprinting B. ELISA C. RT-PCR D. DNA sequencing

C. RT-PCR uses reverse transcriptase to make cDNA from mRNA. The cDNA can then amplified, and then tested for. This is the only method listed that can be used to test for the presence of mRNA and determine if transcription of the gene is occurring or not (choice C is correct). Both DNA Fingerprinting and DNA Sequencing are methods used to analyze DNA sequences; this does not provide information about transcription (choices A and D can be eliminated). While ELISA could be used to test for the presence of a protein product, it would not be the best test to use in this situation (choice B is incorrect). The absence of a protein could be due to a variety of reasons, including problems with translation, protein degradation, etc. Thus, RT-PCR would be a better method to specifically test for gene expression (i.e., transcription).

Which of the following statements primarily differentiates between schizophrenic behavior and schizoid affect? A. Schizophrenics hear voices and schizoids have delusions. B. Schizophrenics have delusions and schizoids have thought disorders. C. Schizophrenics exhibit psychotic behaviors and schizoids withdraw from interactions with others. D. Schizophrenics exhibit flat affect and schizoids have bursts of wild behavior.

C. Schizophrenia is classified as a brain disorder that may include any combination of the following symptoms: positive symptoms (familiarly known as psychotic symptoms such as delusions, hallucinations, thought disorders, or movement disorders) and negative symptoms (a flat affect, a loss of pleasure in everyday life or previously pleasurable activities, and a lack of interest in beginning or continuing with activities or in interacting with others). Cognitive symptoms include poor executive functioning (e.g., decision-making) and trouble with focusing or remembering (choices A, B, C, and D all accurately describe schizophrenic symptoms). "Schizoid" refers to a personality disorder, which is a different diagnostic category, and is characterized primarily by an unwillingness to interact with others. Those with schizoid personality disorder may seem aloof or to be loners, and may or may not prefer that state of being (choice C is correct). Typically schizoid individuals do not have delusions (choice A is wrong), do not have thought disorders (choice B is wrong), and do not demonstrate bursts of wild behavior (choice D is wrong).

The vestibular sense detects motion and is involved in balance by way of what mechanism? A. Control of autonomic functions by the pons B. The endolymph in the cochlea contains hair cells that detect motion and rotation of the head C. The endolymph in the utricle, saccule, and ampullae contain hair cells that detect motion and the rotation of the head D. Coordination of motion in cerebellum

C. The endolymph in the utricle, saccule, and ampullae—the semicircular canal of the inner ear—contain hair cells that detect motion and the rotation of the head. This aids in the sense of balance (choice C is correct). The pons in the hindbrain controls some autonomic functions and coordinates movement and thus is related to the sense of balance but that control of autonomic functions on its own is not the vestibular sense (choice A is wrong). The endolymph in the cochlea contains hair cells that are designed to transmit auditory vibrations for the sense of hearing, not proprioception or balance (choice B is wrong). The cerebellum coordinates complex movements and damage to that area results in difficulties in movement and balance, but again this is not the specific mechanism of the vestibular sense (choice D is wrong).

Which of the following accurately lists the composition of the endoplasmic reticulum, phosphofructokinase and alanine, respectively? A. Double membrane surrounding a lumen, amino acids linked together by covalent proteolytic bonds, four different groups on a chiral Alpha carbon. B. Single membrane surrounding a lumen, amino acids linked together by hydrogen bonds, four different groups on a chiral Alpha carbon. C. Single membrane surrounding a lumen, amino acids linked together by covalent peptide bonds, four different groups on a chiral Alpha carbon. D. Single membrane surrounding a lumen, amino acids linked together by covalent peptide bonds, three different groups on a chiral Alpha carbon.

C. The endoplasmic reticulum is an organelle with a single membrane surrounding a lumen (eliminate choice A). Phosphofructokinase is an enzyme of glycolysis, and so is a protein made of amino acids linked together by covalent peptide bonds (choice B is wrong). Alanine is a chiral amino acid, and so has four different groups on a chiral alpha carbon (another reason to eliminate choice D). Choice C provides an accurate description and is correct.

The melting temperature of the 15-mer oligonucleotide 5'-GACTGCGGTTTTAAC-3' is 42 °C. Which of the following oligonucleotides would be found primarily in a random coil state at 42 °C? A. 5'-GACTGCGGCGCGAAC-3' B. 5'-GCCTGAGGTTTTAGC-3' C. 5'-GACTGTAATGGTAAC-3' D. 5'-GACTGCGGCCCCAAC-3

C. The melting temperature is the temperature at which half of the DNA strands are in the random coil or single-stranded state. As the given oligonucleotide has a melting temperature of 42°C, then the correct answer must be an oligonucleotide with a melting temperature with a lower melting temperature in order to be primarily in the random coil state at 42°C. In order to have a lower melting temperature, the oligonucleotide must contain fewer GC nucleotides than the given oligonucleotide (Choice C is correct; Choices A, B, and D are wrong). This is because GC base pairing involves three hydrogen bonds while AT only involves two.

Compared to sensitive bacteria, phage-resistant bacteria are most likely to display which of the following characteristics? A. Increased sensitivity to antibiotics that disrupt the cell wall B. The presence of plasmid DNA absent in sensitive cells C. Alteration in the amino acid sequence of a specific protein found in sensitive cells D. Increased expression of lysosomal enzymes

C. The results of the experiment are most consistent with the mutation hypothesis, since the initial number of phage and bacteria were held constant, but variable numbers of resistant bacteria were observed. If a mutation is responsible, then this will result in a protein with an altered amino acid sequence, or else the mutation would have no effect (choice C is correct). There is no relationship to antibiotic sensitivity implied (choice A is wrong). A plasmid is not likely to be responsible since the plasmid would have to spontaneously appear in resistant cells where none was present in sensitive cells (choice B is wrong). Bacteria do not express lysosomal enzymes since they would lyse themselves (choice D is wrong).

A therapist uses a white noise machine in her office for privacy; the therapist has been using the machine for years and doesn't even notice the sound it makes when it is on. One of her patients finds that noise produced by the white noise machine very irritating; every time he hears it he becomes more and more agitated. The therapist: A. has become sensitized to the white noise while the patient has become desensitized to it. B. and the patient have both been conditioned to the noise, but with different outcomes. C. has become habituated to the white noise while the patient has become sensitized to it. D. has generalized the white noise while the patient has discriminated it

C. This example demonstrates non-associative learning. Habituation involves becoming so used to a stimulus that it no longer produces a response; the therapist no longer even noticing the sound produced by the machine is an example of habituation. Sensitization involves becoming more responsive to a stimulus; the patient demonstrating increased aggravation by the noise is an example of sensitization (choice C is correct). Desensitization involves trying to no longer respond to a stimulus that one was once sensitized to; the patient is currently sensitized to the stimulus, and would have to engage in an active process in order to become desensitized to it (choice A is wrong). This scenario demonstrates non-associative learning; conditioning is a type of associative learning (choice B is wrong). Generalization (responding with the conditioned response to stimuli other than the conditioned stimulus) and discrimination (responding with the conditioned response to only the conditioned stimulus) are both aspects of classical conditioning, a form of associative learning (choice D is wrong).

The Ka for the first ionization of sulfurous acid (1.7 × 10-2) is significantly larger than the Ka for the second ionization (6.4 × 10-8). A likely explanation for this is that: A. the electronegativity of the remaining hydrogen atom increases after the first hydrogen ion has been removed. B. the second ionization can only take place if the first ionization proceeds to completion. C. neutral hydrogen is difficult to ionize in aqueous solution. D. the remaining hydrogen atom experiences greater electrostatic attraction after the loss of the first hydrogen ion.

D. After loss of the first proton, the remaining hydrogen is bound to a negatively-charged molecule. Electrostatic attraction between this remaining hydrogen and the negatively-charged molecule would disfavor loss of the second proton, resulting in a smaller K. Therefore, K2 << K1.

The serotonin transporter (or SERT) removes serotonin from the synaptic cleft and recycles it back into the presynaptic cell. It thus terminates the effects of serotonin and this mechanism has been targeted in treatments for alcoholism, clinical depression, obsessive-compulsive disorder, and hypertension. SERT spans the plasma membrane 12 times and is also a: A. glycosylated phospholipid, with both hydrophobic and hydrophilic regions. B. peptide chain with at least four levels of protein structure, held together by disulphide and peptide bonds. C. protein with twelve hydrophobic domains, none of which contain the amino acid proline and at least some of which contain Beta-sheets stabilized by covalent bonds. D. protein with twelve transmembrane domains, each of which is an Alpha-helix with no proline and external hydrophobic residues, stabilized by hydrogen bonds.

D. Membrane transport is mediated by proteins, not phospholipids (eliminate choice A). All proteins have at least three levels of protein structure, but only some have quaternary structure. There is no information in the question stem to support the fact that SERT contains more than one peptide chain (eliminate choice B). Transmembrane domains are alpha-helices with external hydrophobic residues. They cannot contain proline because of its secondary amine structure. Both alpha-helices and beta-sheets are stabilized by hydrogen bonds, not covalent bonds (eliminate choice C, choice D is correct).

What is the configuration of the electrons in the valence shell of a chloride anion? A. 3s2 3p4 B. 3s2 3p4 4s1 C. 3s2 3p4 4s2 D. 3s2 3p6

D. The most common chloride anion is of course Cl-, which has the octet configuration in its valence shell (like the noble gas argon). Choice D gives the octet configuration, ns2np6 (with n = 3 since Cl is in Period 3).

Solomon Asch is famous for his study on: A. obedience to authority. B. cognitive dissonance. C. norm violation. D. conformity

D. Solomon Asch conducted the famous line study and others like it in order to study the effects of conformity. Asch presented subjects with pictures of three lines of varying lengths and asked them to match one of the lines to a line that he had on a separate card. Although one choice was clearly correct, when confederates in the room selected a patently incorrect choice the subjects often followed suit. Asch argued that this behavior was due to the pressure to conform (choice D is correct). Stanley Milgram and Philip Zimbardo are known for their experiments on obedience to authority (choice A is wrong). Leon Festinger and James Carlsmith are known for their cognitive dissonance research (choice B is wrong). Rob Cialdini is known for his work on norm violations (choice C is wrong).

Trial 2 At 25°C, 50.0 mL of 2.0 M NaOH was combined with 50.0 mL of 2.0 M HCl. The mixture temperature was recorded as 71°C. If a neutralization similar to Trial 2 were performed with the same molar values of NaOH and acetic acid, which of the following results is the most likely to occur? A. A higher temperature due to a larger |ΔH| B. A lower temperature due to a larger |ΔH| C. A higher temperature due to a smaller |ΔH| D. A lower temperature due to a smaller |ΔH|

D. This is a 2 × 2 style question, and in this case two choices can be eliminated for being internally inconsistent. If the ΔH is larger for an exothermic reaction, more energy will be given off, resulting in a larger increase in temperature (eliminate choice B). Similarly, if less energy is given off, the temperature change should be smaller (eliminate choice C). The heat of neutralization is defined as the enthalpy change resulting from 1 mole of water being produced from the reaction H+(aq) + OH-(aq) → H2O(l). Since weak acids (like acetic acid) are only partially ionized, their neutralization by a strong base will not result in an equal production of water molecules compared with a strong acid/strong base neutralization (eliminate choice A).

Systolic blood pressure approaches 0 mm Hg when it reaches the: A. capillaries. B. arteries. C. aorta. D. right atrium.

D. Blood from the systemic circulation at the end of its circuit through the body enters the heart through the right atrium, and at this point its pressure is near 0 mm Hg (choice D is correct). Although blood pressure is relatively low in the capillaries, it is not 0 mm Hg, or it would never circulate all the way back to the heart (choice A is wrong). Blood leaves the heart through the aorta on its way to the systemic circulation and is at its highest pressure at that point (choice C is wrong); from the aorta the blood travels through many arteries, and the pressure in these vessels is still high (choice B is wrong).

The phenomenon of adjusting one's behavior based on the behavior of others is known as: A. social facilitation. B. obedience. C. motivation. D. conformity

D. Conformity is a process whereby a person changes his or her behavior to be in line with another's behavior (choice D is correct). Social facilitation is a phenomenon whereby being part of group encourages people to work harder (choice A is wrong). Obedience differs from conformity in that the person changes his or her behavior to comply with the demands of an external authority (choice B is wrong). Motivation refers generally to all the possible reasons why people choose to act in particular ways (choice C is wrong).

During the exponential phase of bacterial growth, bacteria are reproducing by: A. sexual reproduction. B. transduction. C. conjugation. D. binary fission.

D. During the exponential phase of bacterial growth, the population is increasing in size. The only choice which allows an increase in population size is choice D, binary fission. Sexual reproduction does not apply to bacteria (choice A is wrong), and while conjugation serves to increase genetic diversity, it does not increase the size of the population (choice C is wrong). Transduction is also a means to create genetic diversity. It occurs when a lysogenic virus excises from the genome and takes a portion of the genome with it. Any new hosts infected by that virus will be given the new genes, however this does not increase the size of the population (choice B is wrong).

Engagement rings are presented as betrothal gifts, often from men to their partners. These tokens would be of interest to which of the following? A. Conflict theorists B. Dramaturgical theorists C. Functionalists D. Interactionists

D. Engagement rings are presents to prospective spouses, but they are also important for another reason: engagement rings indicate that a person has accepted a marriage proposal. Interactionists are interested in micro-level interactions that create social meanings, thus focusing on communication through language and other important social symbols. Therefore, it is likely that interactionists would be interested in engagement rings because societies use these symbols to communicate that a person has made a formal agreement with his or her romantic partner and is now engaged to be married. These meanings help create our impression of the person wearing the ring, and individuals are thus active in shaping their societies, reflecting the arguments of interactionism. Furthermore, social interactions also regulate the practice of wearing the ring; for example, it is customary for engagement rings to be worn on the left ring finger in most Western countries (choice D is correct). The dramaturgical perspective is a specific form of interactionism that is interested in impression management (e.g., the back-stage and front-stage selves), but this is less applicable to the specific token presented upon engagement (choice B is wrong). The marriage-related interests of conflict theorists might be the internal power relations (or, to continue with the example, perhaps the relationship between socioeconomic status and the ranging qualities of the engagement ring, such as status); the pertinent interests of functionalists might be the contributions of marriage to social order. However, neither conflict theorists nor functionalists would be expected to consider the implications of an engagement ring in social interactions (choices A and C are wrong).

Which of the following can be inferred from information in the passage? I. Cardiomyocytes and hepatocytes are mitochondrial rich cells. II. Slow twitch fibers have higher cardiolipin content than fast twitch fibers. III. Prokaryotes pump H+ across their plasma membranes, while eukaryotes do not A. III only B. I and II only Your Answer C. II and III only D. I, II, and II

D. Item I is true: the passage states that cardiolipin constitutes 20% of the total lipid composition of the inner membranes of some eukaryotic organelles, and the table suggests mitochondria are affected in cardiolipin synthesis mutants. This means cardiolipin is likely a component of the inner mitochondrial membrane. The passage also says cardiolipin can be isolated from heart and liver tissue. This means these two tissues must be rich in mitochondria (choices A and C can be eliminated). Note that both remaining choices include Item II, so it must be true: slow twitch fibers have many mitochondria and therefore will have more cardiolipin. Item III is true: based on the endosymbiotic theory, eukaryotic cells acquired mitochondria via endocytosis of a prokaryotic cell. The bacterial plasma membrane contained the electron transport chain machinery and became the inner mitochondrial membrane. The endosome membrane became the outer mitochondrial membrane. As a result, while prokaryotes pump H+ across their plasma membrane, eukaryotes pump protons across the inner mitochondrial membrane. (choice B can be eliminated and choice D is correct).

A patient with elevated parietal cell secretions but restricted mucus secretions will most likely exhibit: A. normal protein catabolism, a gastric ulcer, and a gastric pH that is lower than normal. B. reduced protein catabolism, a gastric ulcer and a gastric pH that is lower than normal. C. increased protein catabolism and a gastric ulcer, but normal gastric pH. D. increased protein catabolism, a gastric ulcer and a gastric pH that is lower than normal

D. Parietal cells are found in the stomach and are responsible for producing HCl, which causes the stomach contents to have a low pH. HCl also non-specifically digests proteins by cleaving peptide bonds, and activates pepsinogen. Elevated parietal cell secretions would mean more acid, and a lower gastric pH (choice C is wrong). More acid would also lead to slightly more protein break down (choices A and B are wrong; choice D is correct). The mucus-secreting cells in the stomach protects gastric epithelial cells from the low pH in the stomach. Reducing mucus secretions can increase the probability of a gastric ulcer, where there is a break in the lining of the stomach.

All of the following contribute to speciation EXCEPT: A. geographic isolation of populations. B. genetic diversity. C. natural selection. D. maintenance of Hardy-Weinberg equilibrium.

D. Speciation requires two populations to become reproductively isolated so that they can no longer interbreed. Geographic isolation is the easiest way to allow two populations to diverge and become reproductively isolated (choice A is true and eliminated). To become reproductively isolated, the populations must diverge genetically, evolving differently, and this would require genetic diversity in the population to begin (choice B is true and eliminated). Natural selection could drive the changes in isolated populations that cause them to evolve into two species (choice C is true and eliminated). If Hardy-Weinberg is maintained, then there can be no changes in the allele frequencies in the gene pool of a population and no evolution, which would not allow speciation (choice D is false and the correct answer choice here).

Lying is often employed as a means of persuasion. Which theoretical model is often used when attempting to determine why someone has been persuaded? A. Yerkes-Dodson B. Cannon-Bard C. Schachter-Singer D. Elaboration-Likelihood

D. The elaboration-likelihood model of persuasion attempts to explain the different ways individuals process stimuli, why they are used, and their outcomes on attitude change. According to the elaboration-likelihood model, there are two major routes to persuasion: the central route and the peripheral route. Under the central route, persuasion will likely result from a person's careful and thoughtful consideration of the persuasive argument; under the peripheral route, the person will focus more on superficial aspects of the argument (catchy-ness, flashy-ness) and spend less time engaging in deep thought about the actual content of the message, so persuasion will occur because of the superficial aspects of the message (choice D is correct). The Yerkes-Dodson Law suggests that performance increases with physiological or mental arousal, but only up to a point. When levels of arousal become too high, performance suffers, which is graphically illustrated as a bell-shaped curve that increases and then decreases with higher levels of arousal (choice A is wrong). The Cannon-Bard and Schachter-Singer theories both attempt to describe how emotion and physiological arousal are related (choices B and C are wrong).

The blood vessel that carries the most highly oxygenated blood in the fetus is the: A. pulmonary vein. B. ductus arteriosus. C. umbilical artery. D. umbilical vein.

D. The most highly oxygenated blood would be the blood returning from the point of oxygenation to the systemic circulation. In the adult this would be the pulmonary vein, but the point of oxygenation in the fetus is the placenta, not the lungs (choice D is correct and choice A is wrong). The ductus arteriosus does carry oxygenated blood but is found after the umbilical vein, so it does not carry the most highly oxygenated blood (choice B is wrong). The umbilical artery carries deoxygenated blood from the fetus to the placenta (choice C is wrong).

Which of the following is the most likely sequence of events in the infection of E. coli by phage T1? A. Replication of viral genome, production of viral DNA polymerase, translation of viral lysozyme, assembly of infectious virus B. Production of viral DNA polymerase, replication of viral genome, translation of viral lysozyme, assembly of infectious virus C. Translation of viral lysozyme, production of viral DNA polymerase, replication of viral genome, assembly of infectious virus D. Production of viral DNA polymerase, replication of viral genome, assembly of infectious virus, translation of viral lysozyme

D. The production of viral DNA polymerase must occur prior to replication of the viral genome since the polymerase is needed to do this (choice A is wrong). The last step must be production of lysozyme since this will lyse the cell, bursting it open and stopping any further activities required to produce infectious virus (choices A, B, and C are wrong). The correct events are in choice D: the expression of the viral DNA polymerase must come first to then replicate the genome. Infectious virus can then be assembled, and released by cell lysis induced by viral lysozyme.

If a teacher remembered a student's unusual name because, coincidentally, it was also the name of the street on which the teacher lived as a child, that teacher's ease in remembering would be an example of: A. explicit memory. B. social learning. C. depth of processing. D. the self-reference effect.

D. The self-reference effect describes how it is easier to remember that which is personally relevant or which can be linked to other memories (choice D is correct). Explicit memory is a type of memory in which one can "declare" and clearly articulate what one knows (choice A is wrong). (choice B is wrong). Depth of processing concerns how deeply one thinks about the issues to be committed to memory. In other words, meaning is more easily remembered than form because one often ruminates more about the former (choice C is wrong).

Stereotype threat is closely related to ultimate attribution errors. A white female is teaching high school social studies to a group of students who are racially and ethnically diverse. Which of the following statements is LEAST supported by the concept of the ultimate attribution error? A. A Hispanic male who was born and reared in California does poorly on a quiz about the United States, and the teacher assumes that he is unfamiliar with the country. B. A black male gets a 100% on a quiz about emperors, and the teacher thinks that he must have cheated. C. A Hispanic female frequently uses slang terms in her essays about North American geography, and the teacher attributes this to her being too lazy to learn proper grammar. D. A black female does poorly on a quiz about capitals, and the teacher assumes that she had been unable to adequately study the night before.

D. The ultimate attribution error occurs when negative behavior by a member of an out-group is attributed by an in-group member to the out-group member's characteristics (e.g., genetics, intelligence, personality, childhood background), while positive behavior by a member of an out-group is rationalized or explained away (e.g., good luck, special circumstances, etc.). Since the teacher explained the black female's poor performance in terms of a personal circumstance pertaining to that specific student, the ultimate attribution error was not made (choice D is least supported by the concept of the ultimate attribution error and is therefore correct). The teacher's assumption that the male Hispanic student is unfamiliar with the United States is based on negative stereotypes about Hispanics (choice A is wrong), as is the teacher's assumption that the female Hispanic student is too lazy to learn proper grammar (choice C is wrong). The teacher's assumption that the black male student only did well because he cheated is explaining away the individual student's good performance (choice B is wrong).

Behavioral theorists explain which personality disorder as the result of having been rewarded for loyalty and punished for acts of independence? A. Histrionic personality disorder, which is characterized by excessive emotionality and attention-seeking behaviors B. Obsessive-compulsive personality disorder, which is characterized by perfectionism and a need for control at the expense of flexibility and efficiency C. Avoidant personality disorder, which is characterized by the avoidance of social interactions (despite a strong desire to be close to others) and an extreme sensitivity to negative evaluation D. Dependent personality disorder, which is characterized by a strong dependence on others to meet emotional and physical needs

D. With dependent personality disorder, individuals demonstrate patterns of clinging and obedience and fear separation, often insisting that they need to be taken care of and protected. Behavioral theorists believe that individuals with dependent personality disorder developed their disorder because of how they were treated by their parents when growing up; they were unintentionally rewarded for being clingy ("loyal") and were punished when they acted on their own (choice D is correct). Histrionic personality disorder, a disorder characterized by excessive emotionality and attention-seeking, is more often explained in terms of children having learned to behave dramatically in order to gain attention from distant parents (choice A is wrong). Obsessive-compulsive personality disorder may arise from struggles with parents over independence and control, but is not thought to involve reward and punishment (choice B is wrong). Behavioral theorists posit that individuals with avoidant personality disorder fail to develop normal social skills and come to expect rejection (choice C is wrong).

from a list of 4 options how would you determine the possible Lewis structure for the disulfide intermediate S2O7(2-)?

Once you recognize that the sum of the formal charges in the Lewis structure must be equal to the overall charge of the ion

Top-down processing

a Gestalt psychology term for interpreting sensory stimuli based on experience and larger contextual information in order to slowly work down and figure out the precise nature of each stimulus

what is an androcentric culture

a culture that is male-oriented; the male is considered the norm and is consistently preferred across the various aspects of the culture. As a result, anything that is related to females and the female experience is relegated to a lower tier of importance.

Histrionic personality disorder

a disorder characterized by excessive emotionality and attention-seeking, is more often explained in terms of children having learned to behave dramatically in order to gain attention from distant parents

Superimposition

a process whereby one stimulus is layered on top of another

Explicit memory

a type of memory in which one can "declare" and clearly articulate what one knows

ketogenic amino acids are broken down into and can be used for what? what are the 2 ketogenic AA?

acetyl-CoA which can be used in fatty acid biosynthesis or ketogenesis lysine and leucine

define social capital

an important mechanism of social reproduction. It includes relationship-based social assets, like influence and "connections" with people in one's social network

what is the IR spectroscopy values for C=O

approx 1700

what is the IR spectroscopy value for O-H

approx 3200

The primary function of the cochlear nuclei

are collections of neurons that receive input from the sound received by the cochlear nerve, and then output that information to the auditory cortex of the brainstem. As the cochlear nuclei are involved in auditory processing,

Muscle spindles

are mechanoreceptors sensitive to the stretch of muscles, and are thus involved in movement and proprioception

Bottom-up processing

the Gestalt term for the reverse process, by which one starts with a small sensory stimulus and integrates progressively more contextual information in order to determine its nature

what happens to childrens thought process during Piaget's concrete operational stage

children begin to exhibit logical reasoning

what happens to childrens thought process during Piaget's preoperational stage

children think more symbolically as they develop memory and imagination

Depth of processing

concerned with how deeply one thinks about the issues to be committed to memory. In other words, meaning is more easily remembered than form because one often ruminates more about the former (

the primary function of the lateral geniculate nucleus

in the thalamus is involved with the visual processing pathway of the brain. It is the primary relay center for visual information received from the retina of the eye, and therefore would be involved in the visual processing

what is a confounding variable?

is a condition that is not accounted for by a study's design and which could distort the results of the study.

Schizotypal personality disorder

is characterized by odd or eccentric behavior and acute discomfort in interpersonal relationships, to the point that people with this disorder rarely have social ties outside of immediate family members. also frequently have notable cognitive or perceptual disturbances

Contextual reception

is simply another way of saying that one is receiving contextual stimuli, not necessarily even processing it

what happens to childrens thought process during Piaget's formal operations stage

is the final stage when children are able to consider abstract relationships and concepts

define Ethnocentrism

is the tendency to believe that one's own ethnic or cultural group is the most important one, and that all other groups are measured against one's own. Ethnocentric thinking typically involves making false or negative assumptions about a minority ethnic or cultural group

independent variable

is the variable that the researchers manipulate which is also called the predictor variable

the primary function of the occipital lobe

is the visual processing center of the brain and contains the visual cortex, which would be involved in the visual processing

Golgi tendon organs

monitor the amount of tension in the tendons and are also involved in movement and proprioception

Social learning

not about memory about learning through observing another and imitating his or her actions

Joint capsule receptors

sense pressure, movement, and tension in the joints and are also involved in movement and proprioception

the temporal lobes are involved in

short-term memory, language comprehension, and emotion; consciously suppressing or inhibiting the truth suggests memory retrieval.

Yerkes-Dodson Law

suggests that performance increases with physiological or mental arousal, but only up to a point. When levels of arousal become too high, performance suffers, which is graphically illustrated as a bell-shaped curve that increases and then decreases with higher levels of arousal

The primary function of the postcentral gyrus is

the processing of the sense of touch

kinetics of any reaction can only affect ?

the rate of the reaction

thermodyanmics of any reaction can only affect ?

the results based on stability

dependent variable

the variable that the researchers do not manipulate and simply measure