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Schachter-Singer Theory

A theory of emotion that states that both physiological arousal and cognitive appraisal must occur before an emotion is consciously experienced.

calculating speed during centripetal force

2πr/T

Nominal

A common example of nominal data is gender; male and female.

brood

A family of young animals

Southern blotting

A hybridization technique that enables researchers to determine the presence of certain nucleotide sequences in a sample of DNA. a technique used to identify specific DNA sequences.

What is the approximate pH of a saturated aqueous solution of hydrochloric acid whose molarity is 10.6 M? A. -1 B. 1 C. 7 D. 13

A is correct. Hydrochloric acid is a strong acid and completely dissociates in aqueous solution. In this solution, the hydronium ion concentration is 10.6 M, which can be approximated as 10 M to make the math easier. The pH is the -log of the hydronium ion concentration: -log[10] = -log[101] = -1. While the typical pH range is normally thought of as ranging from 0 to 14, if the concentration of hydronium ion is greater than 1 M, negative pH values are possible. It is also possible to have pH values greater than 14, i.e. if the hydroxide concentration is greater than 1 M.

What is the approximate pH of a saturated aqueous solution of hydrochloric acid whose molarity is 10.6 M? A. -1 B. 1 C. 7 D. 13

What is the mechanical advantage of using the ramp, as opposed to lifting the gurney straight up? (Ignore any effects of friction.) A. 2 B. 1.5 C. 1 D. 0.5

A is correct. One form of mechanical advantage represents an ability to move a load (do work) using less force than simply lifting the load directly. For an inclined plane, this advantage is represented using the formula: MA = hypotenuse / height From trigonometry, we know this as sin-1. We're told the ramp makes a 30º angle with the ground. This means it is a 30º-60º-90º right triangle, with side ratio of x : x√3 : 2x. Thus: MA = 2x / x = 2 That is, by putting in some measure of force (e.g. 1000 N) you're able to lift an object that would otherwise take twice as much force (e.g. 2000 N) to lift straight up.

Which decision-making phenomenon best explains why researchers told participants that monies held at the end of session one would be used to fund games in session two? A. The house money effect B. The gambler's fallacy C. The prisoner's dilemma D. The Cannon-Bard theory of emotion

A is correct. Paragraph 3 tells us that the researchers sought to avoid excessive risk-taking in session one, so they told the participants that the money earned in the session was not theirs free and clear, but would serve as the financial basis for their participation in the second session. The researchers most likely did this to avoid the subjects treating the money as if it was not important to their continuation in the study. The researchers needed the subjects to think of this money as their own. Thaler and Johnson have found that individual risk-taking behavior is affected by prior gains and losses. They found that after a prior gain, people become more open to assuming risk since the new money is not treated as one's own. This is known as the house money effect. B: The gambler's fallacy is the mistaken belief that, if something happens more frequently than normal during some period, it will happen less frequently in the future, or vice versa. For example, someone who bets on red on a roulette wheel because the last 5 spins have all landed on black. This does not match with the reasoning discussed in paragraph 3. C: The prisoner's dilemma is a standard example from psychological game theory that shows why two completely "rational" individuals might not cooperate, even if it appears that it is in their best interests to do so. D: According to the Cannon-Bard theory of emotion, emotions and bodily changes do not share a cause-and-effect relationship. Rather, they occur simultaneously, following a stimulating event. This is unrelated to the task mentioned in the passage.

When 2 moles of hydrofluoric acid are added to 100 mL of water, the resulting solution has a pH equal to 4. What is the percent dissociation of HF? A. 0.0005% B. 0.05% C. 0.5% D. 5%

A is correct. Remember that HF is a weak acid, meaning that it does not fully dissociate in water. In many weak acid problems, you must use an ICE table and the Ka of the acid to calculate the pH of an acidic solution. However, this question gives us pH outright. Remember, pH = -log[H+], so [H+] = 10-pH. Here, [H+] = 10-4 M. Now, we must understand what is meant by "percent dissociation." The percent dissociation of HF is simply the percent of the original acid concentration that has dissociated into H+ and F- ions. This value is equal to [H+]/[HF] x 100%. Original [HF] = 2 moles / 0.100 L = 20 M [H+]/[HF] = (10-4 M H+) / (20 M HF) = 5 x 10-6 % dissociation = 5 x 10-6 x 100% = 5 x 10-4 % dissociation = 5 x 10-4% = 0.0005% B, C, D: These options may result from errors using scientific notation / order of magnitude.

A student has never been very good at math and is struggling in his algebra course; additionally, this student is pressured by his parents to work more hours at a job rather than do homework. What issues does the student experience? A. Role strain about getting good grades and role conflict about working more hours B. Role conflict about getting good grades and role strain about working more hours C. Role exit about getting good grades and role conflict about working more hours D. Role conflict about getting good grades and role exit about working more hours

A is correct. Role strain involves a problem fitting into an existing role, such as the student's problem with getting good grades. Role conflict involves two roles coming into conflict, such as when the student experiences conflict as a student and worker. B: This option confuses role strain with role conflict. C, D: Role exit involves leaving a role, which is not described here.

Shopper A, a customer at Store 3, rudely screams at a staff member. He then receives a discount plus a free item from the manager while checking out. Shopper B witnesses the event. When it is her turn to check out, she behaves rudely and screams at the staff member too. Which theory best describes how she learned this behavior? A. Social cognitive theory B. Classical conditioning theory C. Operant conditioning theory D. Cognitive dissonance theory

A is correct. Social cognitive theory asserts that people learn by watching others, and if they see someone is rewarded for a behavior, they are more likely to behave that way too. B: Classical conditioning involves pairing two stimuli to produce a specific response. C: Operant conditioning uses reinforcement or punishment to increase or decrease likelihood of an individual's behavior. In this case, the first rude shopper was reinforced for acting like a jerk, so he is more likely to behave that way in the future, but the second shopper hasn't had any consequences to increase or decrease her rude behavior.

If the strong base solution used in the titration curve shown in Figure 2 was 0.10 M sodium hydroxide and the volume of the glycine solution titrated was 20.0 mL, what was the molarity of the glycine solution? A. 0.075 M B. 0.10 M C. 0.13 M D. 0.15 M

A. 0.075 M A is correct. From Figure 2, the sharp increase in pH that occurs at 15 mL of added NaOH solution represents the equivalence point, at which the carboxylic acid group is fully neutralized. This can be used to calculate the concentration of the glycine solution, assuming a stoichiometric ratio of 1:1 with the sodium hydroxide. Strictly speaking, you should convert the volumes to liters, but as long as you keep both volumes in milliliters, the units will cancel out in the dimensional analysis (factor-label) calculation. 15 mL NaOH x [0.10 mole/L] x [1 glycine/1 NaOH] x [1/20 mL] This simplifies to: [15/20] x 0.10 = (3/4) x 0.10 = 0.075 moles/L

In which of the following molecules does the carboxylic acid functional group have the highest Ka? A. CH3CF2COOH B. CHF2CH2COOH C. CH3CHFCOOH D. CH3CH2COOH

A. CH3CF2COOH A is correct. A higher Ka is associated with stronger acidity. Adding electron-withdrawing functional groups (like fluorine atoms) provides inductive stabilization of the conjugate base by pulling electron density away from the negatively-charged position (shown below). This stabilization increases the acidity of the original compound. Inductive effects increase if the electron-withdrawing groups are closer to the acid and if more of them are present. Therefore, choice A is the most acidic.

When calculating the amount of product formed during alcohol fermentation, one mole of ethanol is chemically equivalent to what volume of CO2 (g) measured at 1 atm and 273 K? A. 11.2 L B. 22.4 L C. 33.6 L D. 44.8 L C6H12O6 → 2 CO2 + 2 CH3CH2OH

B is correct. 1 atm and 273 K are the temperature and pressure conditions of STP. At STP, one mole of an ideal gas occupies a volume of 22.4 L. From Reaction 1, we see that for each mole of carbon dioxide gas produced by the fermentation of glucose, one mole of ethanol is produced. Therefore, in calculating the amount of ethanol formed during alcohol fermentation, one mole of ethanol is chemically equivalent to 22.4 L of carbon dioxide gas evolved.

If it was found that individuals in the first study who took Truvada but had a high level of perceived stigma relating to Truvada use were more likely to use condoms than those who took Truvada but had a low level of perceived stigma relating to Truvada use, then which of the following terms would best describe the role of perceived stigma on the relationship between taking Truvada and using condoms? A. Mediating variable B. Moderating variable C. Confounding variable D. Dependent variable

B is correct. A moderating variable is one that either decreases or increases the strength of an association. In this case, perceived stigma moderates the relationship between taking Truvada and using condoms. A: A mediating variable is one that provides a causal link between two variables that show a statistical relationship. C: A confounding variable is one that affects two variables that show a relationship. If this was the case for perceived stigma, it would mean that perceived stigma affected BOTH likelihood to use Truvada and condom use. This is not possible in the context of this study since participants were randomized to receive Truvada.

Assuming a 95% yield for each coupling step, what would be the final yield for synthesizing a 10 amino-acid length peptide? A. 30% B. 60% C. 80% D. 95%

B is correct. Each time we add an amino acid to the chain, we get a 95% pure yield for that step. Here, imagine that each coupling step has a 95% yield and that we are running the cycle 9 times (since no coupling step is needed for the first of the 10 amino acids), with each cycle being independent from the preceding cycle. Thus, a 10-amino acid peptide would be synthesized in a (0.95)9 = 0.63 ≈ 60% final yield. This can be assured because the passage allows us to assume a 100% yield in each unprotection step. There is no need to calculate it all out. A crude estimate of the yield would be that 9 steps, in each of which 5% is lost (corresponding to a 95% yield), would result in 45% being lost. However, the actual yield will be somewhat higher, because each step does not involve exactly a 5% reduction from the starting percentage. 60% is the best approximation.

Which of the following statements accurately describes a major assumption of the functionalist theory of social stratification? I. Social stratification affects what people believe about themselves and others and influences their daily life, lifestyle choices, and interactions with others. II. Social stratification is unnecessary and results from both lack of opportunity and discrimination against the poor and people of color. III. Social stratification is necessary and results from the need for those with special intelligence, knowledge, and skills to be a part of the most important professions and occupations. A. I only B. III only C. I and II only D. I and III only

B is correct. Functionalist theories assert that aspects of culture are necessary and need-based. I: This statement describes symbolic interactionism in relation to social stratification. II: This statement describes conflict theory in relation to social stratification.

A 50-kg child is riding on a playground merry-go-round. If the radius of the circular path of the merry-go-round is 5.0 m and the frequency is 0.1 hertz, what is the force required to keep the child on the ride? A. 25 N B. 100 N C. 1000 N D. 2500 N

B is correct. If the frequency of the merry-go-round is 0.1 Hz, then the period is 10 s. We can calculate the speed of the merry-go-round from V = 2πr/T = 2(3.14)(5.0 m)/(10 s) = 3.14 m/s. Using this in the centripetal force equation: Fc = mv2/r = (50 kg)(3.14 m/s)2/(5.0 m) Approximate the square of the speed at 10 m2/s2. Fc = (50)(10)/(5) = 100 N

Assuming that the children studied are 6-7 years old and are in the normal stage of Piaget's stages of cognitive development, which of the following would most likely be observed among these subjects? A. An ability to mentally manipulate information B. A high degree of symbolic play C. Empathy based on understanding the viewpoint of another child D. An ability to solve puzzle games using simple deductive logic

B is correct. In Piaget's stages of development, children from ages 2 to 7 are in the pre-operational stage of development. At that level, children learn to operate symbolically and engage in a lot of symbolic play (e.g. a stick is a sword, a plastic toy is a cake, a doll is a person, etc.).

Arachidonic acid, released during AEA hydrolysis, is NOT a precursor for the synthesis of what class of molecules? A. Prostaglandins B. Catecholamines C. Thromboxanes D. Phospholipids

B is correct. In the first paragraph of the passage, it's written that AEA is degraded to ethanolamine and arachidonic acid. Ethanolamine is included as a polar head group in the phospholipid phosphatidylethanolamine, while arachidonic acid is important as a precursor for the biosynthesis of the eicosanoid signaling molecules: prostaglandins, thromboxanes, and leukotrienes. Neither molecule contributes to the synthesis of catecholamines, which are a class of molecules derived from tyrosine. A, C: Prostaglandins and thromboxanes are both classes of prostanoids derived from arachidonic acid. D: Ethanolamine is found in the phospholipid phosphatidylethanolamine; arachidonic acid is a polyunsaturated fat found in phospholipids, especially p

What type of cultural norm is most directly involved in health behaviors? A. Folkways B. Mores C. Taboos D. Laws

B is correct. Mores are norms that are deemed highly necessary to the welfare of a society and have consequences if violated. Health behaviors (like seeking help for an acute medical illness) are standards of behavior that are necessary for the well-being of everyone; if a person does not seek help, they may be shunned by family members or friends. A: Folkways are norms that govern everyday behavior (like holding a door open). For example, imagine a young woman who is unmarried but decides to live with her boyfriend. Her parents are very religious and belong to a community in which only married couples are supposed to live together. In the parents' eyes, the daughter has broken a more, and the parents will levy sanctions accordingly. In contrast, folkways are informal norms that have less significance attached to them but that still influence everyday behavior. Breaking a folkway usually brings with it less severe consequences than breaking a more. For example, if someone is at a fancy steak dinner and begins eating with their hands, he or she is breaking a folkwa

Which of these statements describe(s) primary aging? I. Aging related to social factors and environmental context, like changes in romantic relationships II. Aging related to biological factors and the physical body, like molecular changes III. Aging related to controllable behavioral factors, like changes in diet and exercise A. I only B. II only C. I and III only D. II and III only

B is correct. Primary aging describes the aging of biological factors and the physical body. I: There is no term that specifically describes how people age within social contexts. III: Aging that relates to behavioral factors like diet and exercise is defined as secondary aging.

In order to find the concentration of metal ions needed to determine the distribution coefficient of copper (II), what calculation could the researchers have performed in addition to the procedure described in the passage? "after the two phases were separated completely, concentrations of the metal remaining in the aqueous phase were determined spectrophotometrically at 820 nm." A. Average the concentrations of metal ions in the aqueous and organic phases after extraction. B. Subtract the concentration of metal ions in the aqueous phase after extraction from the concentration before extraction. C. Subtract the concentration of metal ions in the organic phase after extraction from the concentration before extraction. D. Average the concentrations of metal ions in the organic phase before and after extraction.

B is correct. The passage defines the distribution coefficient as "the ratio between the concentration of metal in organic and aqueous phase following extraction." In order to determine D, the researchers must know the concentrations of metal ions in the organic phase and of the metal ions remaining in the aqueous phase following the extraction. According to the description provided by the passage of the researchers' procedure "after the two phases were separated completely, concentrations of the metal remaining in the aqueous phase were determined spectrophotometrically at 820 nm." This measurement provides the concentration of metal ions remaining in the aqueous phase directly. The concentration of metal in the organic phase after the extraction is not directly known. However, the passage also indicates that the concentration of metal contained in the aqueous solution prior to extraction is known—"researchers performed a series of extractions of a known concentration of copper (II) nitrate in aqueous solution." In order to determine the concentration of metal ions in organic solvent after extraction, the researchers could use the known concentrations of metal in aqueous solution before and after extraction—the difference, found by subtracting the value, should equal the concentration of metal ions in the organic phase after extraction. A, C, D: These values would not be required in order to calculate the distribution coefficient of the extraction.

According to the passage, which of the following relationships must hold? (Note: 1 m3 = 1000 L.) A. 100 kPa is equivalent to 100 kJ/L. B. 100 kPa is equivalent to 100 J/L. C. 100 Pa is equivalent to 100 J. D. 100 kPa is equivalent to 100 J.

B is correct. This is a unit conversion problem: 100 kPa = 100,000 Pa = 100,000 N/m2 = 105 N/m2 100 J/L x (1000 L/m3) = 105 J/m3 = 105 Nm/m3 = 105 N/m2

Which of the following is NOT a correct description of a cognitive bias that adolescents may experience when making health-related decisions? A. Availability heuristic; judging an event to not be risky because friends have not suffered consequences B. Negativity bias; only focusing on the good aspects of alcohol use and ignoring the bad C. Social desirability bias; peers report using more substances than they really did, leading others to follow suit D. Self-serving bias; interpreting that one's positive experiences with substances are due to positive personality traits and dismissing negative experiences with substances as due to external factors

B is correct. This is an incorrect pairing of bias and description. Negativity bias is when the negative aspects of a situation are focused upon, not the good aspects.

If pharmacologists wished to convert morphine into a form available to brain tissue, which of the following changes could be made to its molecular structure to allow for the best chance to use the drug as a direct brain treatment? A. Attach a glucose molecule to the nitrogen atom B. Replace the alcoholic protons with acetyl groups C. Lyse the molecule to make it smaller D. Remove all double bonds from the molecule

B is correct. This question asks us to consider the structure of morphine given in the passage. What needs to change for morphine to enter the brain while maintaining its function? We are told in the passage that lipid-soluble molecules are able to pass through, while hydrophilic molecules are not. Morphine is hydrophilic in part because of its hydroxyl groups. So, replacing them with acetyl groups would allow the drug to become more lipophilic; although the C=O bond in the acetylated molecule is polar, it cannot undergo hydrogen bonding, so the acetylated structure is effectively much more lipophilic than the original structure with -COOH groups. Interestingly, diacetylated morphine is heroin. The effects and pharmacology of heroin are somewhat distinct from those of morphine, although they belong to the same general class of opiates, and heroin does indeed more readily cross the BBB. A: This would only make the molecule bigger and do little for its polarity. Additionally, while glucose can pass through the blood-brain barrier, adding glucose to another molecule would not necessarily allow that molecule to utilize glucose transport proteins.

In the electron transport chain, which of the following is the component that is reduced but never oxidized? A. Ubiquinone B. Oxygen C. Nicotinamide adenine dinucleotide D. ADP

B is correct. This question is testing your knowledge of the electron transport chain. Almost all elements in the chain are at some point reduced and oxidized. This is the driving force behind the electron transport chain. However, at the end of the chain, oxygen is reduced to form H2O, which is the end fate of the electrons in the chain. ADP is oxidized to ATP.

***47: The pKa values for cysteine are shown below. At what pH will a solution of 2.2 M cysteine be isoelectric? A. 1.96 B. 5.07 C. 8.18 D. 9.15

B is correct. We need to determine the pH at which Cys will be isoelectric, which means having no net electric charge. There are two ways to solve this question. First, we can use the given pKa values to determine the charge that Cys will carry in each solution. Alternatively, we can recall that an amino acid will be in its zwitterion (i.e. isoelectric) form when the pH of the environment is equal to the pKa of the amino acid. This means we need to take the average of the two most relevant pKa's on cysteine. While Cys is not commonly listed as an acidic amino acid, its side chain includes a thiol (-SH) group, which can be deprotonated/made negative. A way to figure this out is to note that the structure of cysteine at pH = 7 shows that the side group is protonated. So it must be that even though the pKa is 8.33, the thiol is able to act as an acid (reminder, a pKa > 7 does NOT mean the group is basic). For amino acids with acidic side chains, the isoelectric point is the average of the two most acidic (lowest) pKa's. pKa = (8.18 + 1.96) / 2 = 10/2 or approximately 5 Alternatively, we can evaluate each choice and calculate the overall charge on the Cys residue. At the pH of choice B (the correct answer), the COOH group will be deprotonated (-1 charge), the amino group will be protonated (+1 charge), and the side chain will be protonated (neutral charge). As such, the overall net charge on the molecule will be 0.

Which of the following is an accurate statement regarding mitosis and meiosis? A. Mitosis results in two haploid daughter cells. B. During mitosis and meiosis II, sister chromatids are separated. C. During meiosis I and meiosis II, sister chromatids are separated. D. Meiosis I results in two diploid daughter cells.

B. During mitosis and meiosis II, sister chromatids are separated. B is correct. This question is asking us to recall some facts about mitosis and meiosis. Remember that mitosis separates sister chromatids to create two diploid daughter cells. Meiosis I separates homologous chromosomes to create haploid daughter cells, each of which divides again, separating sister chromatids in Meiosis II to create two haploid cells. A: Mitosis results in two diploid daughter cells. C: During meiosis I, sister chromatids are not separated. D: Meiosis I results in two haploid daughter cells.

Meiosis I results in two ________ daughter cells.

haploid

A circuit is comprised of a 12-volt battery with three light bulbs with the same resistance. If two of the light bulbs are wired in parallel and are in series with the third light bulb, what happens when one of the parallel light bulbs is unscrewed? A. All of the light bulbs remain lit. B. Two of the light bulbs remain lit. C. One of the light bulbs remains lit. D. All of the light bulbs go out.

B. Two of the light bulbs remain lit. B is correct. Even after unscrewing one of the parallel light bulbs, there is still a circuit for current to flow from the positive terminal to the negative terminal of the battery through the two remaining light bulbs. A: Here, "all" of the light bulbs refers to all three bulbs. However, since one bulb has been unscrewed — and thus entirely removed from the circuit — it will not remain lit.

The figure below depicts two anomeric forms of a sugar. These isomers can best be described as: A. enantiomers. B. conformers. C. diastereomers. D. constitutional isomers.

C is correct. Anomers are a form of epimer. Epimers are sugars that differ only at one stereocenter, with all other stereocenters being exactly the same. Thus, epimers are a type of diastereomer, and choice C is correct. The stereocenter at which these structures differ is circled below. Note that the structure on the left is the alpha anomer, since the -OH group on its anomeric carbon points in the opposite direction (down from the ring) from the CH2OH group (which points upward). In contrast, the structure on the right, which has its -OH group pointing upward, is the beta anomer.

Pentane is a straight-chain hydrocarbon with the molecular formula C5H12. How many additional structural isomers can be constructed using this molecular formula? A. 0 B. 1 C. 2 D. 3

C. 2 C is correct. Since the molecular formula follows the CnH2n+2 formula, we can only build alkanes. This makes the job of finding isomers much easier. We can make a tertiary carbon, 2-methylbutane. We can make a quaternary carbon, 2,2-dimethylpropane. And that's it.

Which of the following is/are examples of conflict theory in society? I. A trade union forming to promote workers' rights at the cost of company owners II. A company maximizing profits for shareholders at the expense of its middle- and lowest-tier employees III. Families paying taxes for the education of their children in public schools A. I only B. II only C. I and II only D. I, II, and III

C is correct. Conflict theory states that individuals compete with each other in society over limited resources. Because of this, certain institutions, such as corporations, rise to the top, which statement II reflects. Groups can also come together, such as in a union (statement I). III: This is an example of functionalism, in which goods and services are traded.

According to Erikson's stages of development, which basic conflict would the individuals studied by the researchers experience? (old ppl in senior homes) A. Generativity vs. stagnation B. Intimacy vs. isolation C. Ego integrity vs. despair D. Identity vs. role confusion

C is correct. Ego integrity vs. despair is a basic conflict that emerges when an individual reaches maturity (at 65 and older) and is reflecting on his or her life. A: Generativity vs. stagnation is a basic conflict that occurs during middle adulthood (ages 40-65), when individuals are trying to balance employment and being parents.

What is the difference between the maximum and minimum volume of air in the lungs of an 80-kg man? (max= 80ml/kg, min=15ml/kg) A. 0.5 L B. 3.4 L C. 5.2 L D. 6.4 L

C is correct. From Figure 1, we see the maximum volume held in the lungs is 80 ml/kg, while the minimum is 15 ml/kg. This is a difference of 65 ml/kg, which, for an 80-kg man, amounts to (65 ml/kg)(80 kg) = 5200 ml, or 5.2 L.

Which of the following changes occur immediately following the consumption of a carbohydrate-rich meal? A. Insulin secretion decreases; G6PD activity increases. B. Insulin secretion decreases; G6PD activity decreases. C. Insulin secretion increases; G6PD activity increases. D. Insulin secretion increases; G6PD activity decreases.

C is correct. From outside knowledge, we know that insulin secretion increases after a meal to help the cells take up glucose from the bloodstream. The passage states that the PPP is a parallel (alternative) path to glycolysis, so it makes sense that it would also be activated when blood sugar levels rise after a meal. D: G6PD activity would not decrease after carbohydrate consumption. insulin activates GLUT transporters for glycolysis

Which of the following was NOT a finding by Harry Harlow in his experiments with rhesus monkeys and their pairing with a simulated mother made from wire (Wire Mother) or one made from soft cloth (Cloth Mother)? A. Monkeys paired with Wire Mothers drank similar amounts of milk and grew at a rate comprable to monkeys paired with Cloth Mothers. B. Monkeys paired with a Wire Mother sought soothing from their "mothers," but at a rate less than monkeys paired with Cloth Mothers. C. After early neglectful conditions, monkeys' abnormal behavior could be corrected by pairing them with the appropriate simulated mother. D. When given a choice, monkeys spent more time holding Cloth Mothers than Wire Mothers.

C is correct. In Harlow's experiment, the infant monkeys preferred spending their time clinging to the cloth mother. Even when only the wire mother could provide food, the monkeys visited her just to eat. Harlow concluded that there was much more to the mother/infant relationship than milk and that this "contact comfort" was crucial to the psychological development and health of infants. After monkeys were paired with a Wire Mother, they showed abnormal behavior, which could NOT be corrected later in life by pairing them with a Cloth Mother. A: This is true. Monkeys with both Cloth and Wire Mothers drank similar amounts and grew similar amounts. B: This is true. In fact, monkeys paired with Wire Mothers very rarely sought soothing from their "mothers" at all and went almost only to eat. D: This is true. Monkeys held Cloth Mothers more than Wire Mothers when given a choice.

What is the main difference between the two studies described? A. Study 1 involved operant learning, while Study 2 involved classical conditioning. B. The conditioned response was only assessed in Study 1. C. The order of the US and CS was different in the two studies. D. Study 1 was qualitative, while Study 2 was quantitative.

C is correct. In Study 1, the CS (the pictures) was presented before the US (the smell or food). In Study 2 the US (the face) was presented before the CS (the product). A: Both studies involved classical conditioning. B: The conditioned response was assessed in both studies. D: Both studies asked participants to rate their preferences, which is quantitative.

A public health advocacy group has developed a program to encourage adherence to a Truvada medication regimen using operant conditioning principles. An example of the group using thinning in the program is: A. reducing the number of participants in the program. B. reducing the prompts used to remind participants to take medication. C. reducing the frequency of rewards for medication compliance. D. changing the reinforcement schedule from variable to continuous.

C is correct. In operant conditioning, thinning refers to reducing the frequency of rewards for a given action.

In a follow-up experiment, two identical gurneys are placed side-by-side on a ramp with their wheels locked to eliminate spinning. Gurney 1 has a dummy placed on it to give it a total mass of 200 kg, while Gurney 2 is loaded with a dummy that makes it only 50 kg overall. If the ramp has a coefficient of friction of μs, which gurney is more likely to slide down the ramp? A. Gurney 1, due to the increased force of gravity B. Gurney 2, due to the reduced force of static friction C. Gurney 1 and Gurney 2 are equally likely to slide. D. Neither gurney can slide unless the wheels are unlocked.

C is correct. In order for the gurney to slide down the ramp, the force pulling it downward (mgsinƟ) must be greater than the static frictional force (μsFN = μsmgcosƟ). The net force on each gurney is thus Fnet = (mgsinƟ) - (μsmgcosƟ). Since net force is equal to the product of mass and acceleration, we can rewrite this equation as ma = (mgsinƟ) - (μsmgcosƟ), where an acceleration greater than 0 means the gurney will slide down the ramp. The mass of the gurney is present in all terms and can be canceled, meaning that it is not a factor in whether the gurney slides. Thus, both gurneys have an equal likelihood of slipping down the ramp, regardless of the fact that they have different total masses.

Meiosis I results in: A. 2 diploid cells with 46 chromosomes, each chromosome consisting of 2 sister chromatids. B. 2 haploid cells with 46 chromosomes, each chromosome consisting of 1 chromatid. C. 2 haploid cells with 23 chromosomes, each chromosome consisting of 2 sister chromatids. D. 2 diploid cells with 23 chromosomes, each chromosome consisting of 1 chromatid.

C is correct. Meiosis I results in 2 haploid cells, each with 23 chromosomes consisting of 2 sister chromatids per chromosome. In the male, the sister chromatids are split into 4 gametes during meiosis II. For females, meiosis I results in a secondary oocyte (a gamete) and a polar body. Penetration of the secondary oocyte by a sperm brings on anaphase II. Telophase II produces a zygote and a second polar body. Remember for the MCAT: mitosis results in diploid daughter cells, while meiosis results in haploid cells to produce gametes.

Which of the following variables are negatively correlated with globalization? A. Number of multi-national corporations B. Internet usage C. Protectionism D. Trade agreements

C is correct. Protectionism refers to a country rejecting trade with others and being isolative, which is inversely proportional to globalization. A, B, D: All of these variables increase as globalization increases.

The music children listen to conveys certain typical social situations and the expected emotional reaction to those situations in a simple, repetitive way that allows children and adolescents to more easily internalize. This process of internalizing the expected reactions to life situations is: A. the main mechanism of assimilation. B. more effective in infants than adolescents. C. a normal part of the socialization process. D. likely to lead to discrimination.

C is correct. Socialization is the process of internalizing the social norms and values expected in one's society, and mass media (such as popular music) is one source of normal socialization. A: Assimilation is a sociology term that occurs when an individual from one culture gradually takes on characteristics of another culture. This question relates more to the initial process of learning about life (socialization) than the process of adopting a new culture once already socialized (assimilation). B: Infants are somewhat young to experience socialization through music, and certainly would not be expected to socialize more readily than adolescents. D: Discrimination is not directly involved in the situation in the question stem.

Based on the information in the passage, compared to the T11 residue, the T3 residue is: A. closer to the C-terminus, and that terminus is likely to be positively charged in vivo. B. closer to the C-terminus, and that terminus is likely to be negatively charged in vivo. C. closer to the N-terminus, and that terminus is likely to be positively charged in vivo. D. closer to the N-terminus, and that terminus is likely to be negatively charged in vivo.

C is correct. The T11 (threonine at position 11) residue was introduced in the beginning of the third paragraph with T3 being discussed later in the same paragraph. The amino acid structure of a protein is conventionally written from the N-terminus to the C-terminus, meaning that the T3 residue (which is the third residue in the protein) must be closer to the N-terminus than T11. In vivo means "in the living" which indicates we are talking about the conditions found inside the living human body. Physiological pH ranges from 7.2 to 7.4, and at this pH, the N-terminus tends to exist in the form of a positively charged -NH3+ group.

Which statement best explains why the lung volume in Figure 1 never drops below 15 ml/kg? A. Since PV is constant, pressures below that value will cause ruptures in the lung tissue. B. At this volume, maximum contraction of the diaphragm has forced out as much air as possible from the lungs. C. The residual volume is such that the lungs are at their minimum volume under maximum intrapleural pressure. D. Below this volume, spontaneous lung collapse will occur, and the body has evolved safeguards.

C is correct. The best way to approach this question is by process of elimination. It can be helpful to first eliminate answers that are untrue, and then to eliminate true choices that do not answer the question. Reasoning for how to eliminate each option is shown below. Once we eliminate options A, B, and D, we see that choice C is both accurate and relevant to the question stem: this 15 mL/kg of air is the residual volume, which is the minimum volume the lungs can have, and which is attained at maximum intrapleural pressure. A: Remember, work = PΔV, so PV would not be constant in a case where work is being done on or by a mass of air. Additionally, you may be thinking of the ideal gas law, where for a certain number of moles of an ideal gas at constant temperature, PV is constant. During breathing, however, the molar amount of air in the lungs changes over time. B: This is tempting, but read each answer closely. We must know for test day that contraction of the diaphragm flattens the muscle and increases thoracic volume. This facilitates inspiration, not expiration (as would be expected to explain minimum lung volumes). Forced exhalation beyond the norm uses not the diaphragm muscles (which simply relax during expiration), but the intercostal muscles. D: This is true because if air was forcibly removed from the lungs, below a certain point, the lungs would collapse under intrapleural pressure. However, this will not occur spontaneously from exhaling with too much force. That leaves only C, the sole working statement. Pressure and volume are inversely related, so under maximum pressure, the lungs will reach a minimum volume. This volume of air remaining in the lungs is termed the residual volume.

Given the data discussed in the passage, if a hospital requires at least 250 g of 145Nd to complete a standard cardiac image, how long will it be before it must replace a 2000 g sample? A. 25 minutes B. 50 minutes C. 75 minutes D. 100 minutes In experimental assays, approximately 93% of the 145Pm decay product is produced in the first 100 minutes

C is correct. The decay of a substance can be calculated by knowing its half-life, the time it takes for half of the original amount to decay. The final paragraph states that about 93% of the decay occurs in the first 100 minutes. This leaves about 7% of the sample left, which would indicate that close to 4 half-lives (0.54 = 0.0625 = 6.25% remaining) have passed at the 100-minute mark. Thus, 1 half-life = 100/4 = 25 minutes. The hospital sample is 2000 g and must be replaced once it reaches 250/2000, or 1/8 of its original radioactivity. Using the shortcut that the amount remaining = (1/2)n, where n represents the number of half-lives that have passed, we can calculate 1/8 = (1/2)3. Therefore, 3 half-lives will pass before the sample drops below 250 g. At 25 minutes apiece, 25 min (3) = 75 minutes.

The most appropriate way to explain the impact of the short-term stress exposure used in the experiment on individual decision-making would be to cite: A. parasympathetic response. B. activation-synthesis hypothesis. C. general adaptation syndrome. D. theory of cognitive appraisal.

C is correct. This is a classic MCAT question where we need to match the general activity/details of the passage to some psychological or sociological concept. We need to find the answer that encompasses the effects of short-term stress on the psychological state of the individual (since the Q asks about impact on decision making). General adaptation syndrome is a term created by Hans Selye to describe the body's short-term and long-term reactions to stress. Selye thought that the general adaptation syndrome involved two major systems of the body, the nervous system and the endocrine system. He then went on to outline what he considered as three distinctive stages in the syndrome's evolution. He called these stages the alarm reaction (AR), the stage of resistance (SR), and the stage of exhaustion (SE). A: Although the general adaptation syndrome does involve the nervous system, it is more likely to involve the sympathetic response, which involves the release of epinephrine and norepinephrine during the "fight-or-flight" response to stress or danger, as assessed by the body. Instead, the parasympathetic system is involved in the "rest-and-digest" response, which would not be the primary mediator of the stress response. B: Activation-synthesis theory deals with the differences in neuronal activity of the brainstem during waking and REM sleep, and the hypothesis proposes that dreams result from brain activation during REM sleep. D: The "theory of cognitive appraisal" explains the mental processes which influence the stressors. According to the theory, stress is a two-way process; it involves the production of stressors by the environment as well as the response of an individual subjected to these stressors. Cognitive appraisal occurs when a person considers the threat posed by and the resources needed to minimize the stressors affecting them. In this study, the subjects were simply asked to make a decision, not to address their anxiety or the stressors causing it.

Based on mass, which of the following molecules will most easily pass through a gap junction? A. An RNA sequence of 3 uracil nucleotides B. Rotigaptide C. An Ala-Leu dipeptide D. A triglyceride with 3 hexadecanoic acid molecules

C is correct. We could do the math for this question and determine the exact mass of each of the answer choices. However, we want to work smarter, not harder, so let's see if we can determine the smallest (by mass) molecule here. By far, the smallest molecule listed is the two-amino-acid chain of alanine and leucine. The heaviest amino acid, tryptophan, weights 204 Da. Thus, two bound residues must weigh 408 Da or less. This is much smaller than the other answer choices. If you did the math, you would find that each amino acid has 2 carbon, 2 oxygen, 1 nitrogen, and 4 hydrogen atoms. Alanine has a methyl side chain (1 C, 3 H), while leucine has an isobutyl side chain (4 C, 9 H), for an additional 5 carbon and 12 hydrogen atoms and a total of 9 C, 2 O, 2 N, and 20 H. This is by far the smallest molecule presented. A: One nucleotide consists of a ribose sugar, a phosphate group, and a nitrogenous base. The phosphate group contains 1 P and 4 O atoms. The ribose consists of 3 O and 5 C atoms, while the nitrogenous base includes at least 1 N and 6 C atoms. Adding this up, we get 35 + 7(16) + 11(12) + 14 = 293. So, three attached nucleotides of any kind would put us above 800 Da, well over choice C.

Increasing velocity __________ pressure.

If the pressure inside the artery drops far enough, it may fall below the pressure outside the artery, causing it to collapse from external pressure.

Which of the following is a kinship of affinity? A. Grandparents rearing their grandchildren B. Extended families living in the same household C. A husband and wife merging their children from a previous marriage D. Divorced parents sharing custody of their children

C. A husband and wife merging their children from a previous marriage C is correct. A kinship of affinity is one in which individuals are related by choice, such as through marriage, rather than through blood, such as the other choices. A, B, D: All of these choices describe blood relations. According to the former system (which distinguishes on the basis of closeness), primary kinship involves a direct relationship, such as that between a brother and sister or between a father and daughter. Secondary kinship exists between an individual and "the primary kin of that person's primary kin." For example, the relationship between a grandson and his paternal grandmother would typically be secondary kinship, since the grandson is primary kin with his own father, who is primary kin with his mother (the grandmother). Finally, tertiary kin is one step further removed, and can refer to primary kin of one's primary kin's primary kin (three levels!) or to the secondary kin of one's primary kin, such as one's husband's grandmother. According to the latter system (which distinguishes by the nature of the relationship), affinal kinship, or a "kinship of affinity," exists without blood relationship, with the most common example being kinship due to marriage. In contrast, consanguineal kinship is based on blood - or genetic - relationship.

What is a likely explanation for the difference in column affinity exhibited by the perpromethate and the neodymate? A. Perpromethate nuclei have greater atomic masses and are therefore unable to form tight bonds to the column. B. Neodymate atoms have a greater mass defect and are unable to form covalent bonds to the column. C. Perpromethate ions carry less charge than the neodymate ions, and their electrostatic attraction to the column will be less. D. The potassium ions in the solution are able to surround the neodymate ions more efficiently than the perpromethate ions. neodymate, NdO42-, is adsorbed onto a gallium oxide (Ga2O3) colum perpromethate, PmO 4-, which is less tightly bound to the gallium.

C. Perpromethate ions carry less charge than the neodymate ions, and their electrostatic attraction to the column will be less.

Imine

C=N. A double bond between a carbon and a nitrogen

Amide

Carboxylic acid derivative, -CO-NH2

What would be a possible ratio level measure of religiosity? A. Whether or not a person believes in God B. The type of religion with which a person identifies C. The degree of one's belief in afterlife D. The number of times a person has been to church in the last month

D is correct. A ratio level of measurement is one in which there are a range of quantitative responses, ordered at equally-spaced intervals, and with it being possible to score 0 (complete absence of the quantity). A: This is a binary nominal level of measurement. B: This is a nominal level of measurement. C: This is an ordinal or interval level of measurement, without the possibility of a measurement of 0.

Air is bubbled through distilled water. The solution will have a pH: A. greater than 7, because elemental nitrogen undergoes hydrolysis. B. less than 7, because elemental nitrogen undergoes hydrolysis. C. greater than 7, because carbon dioxide undergoes hydrolysis. D. less than 7, because carbon dioxide undergoes hydrolysis.

D is correct. Air contains elemental nitrogen as its major component, but elemental nitrogen is essentially inert and is neither an acid nor a base. On the other hand, carbon dioxide can undergo a hydrolysis reaction in liquid water to produce carbonic acid, a weak acid that produces a solution whose pH is less than the pH of water (pH = 7).

What characteristics of society are associated with high levels of anomie? I. Rapid changes in society II. Low levels of income III. High heterogeneity A. I and II only B. I and III only C. II and III only D. I, II, and III

D is correct. Anomie refers to society feeling fragmented and lacking cohesiveness. All of the characteristics listed are associated with anomie.

Two known competitive inhibitors were studied to analyze their effects on the reaction rate catalyzed by the enzyme lysozyme. Equimolar amounts of inhibitor A (hydronium ion) and inhibitor B (hydroxide ion) were mixed in a beaker before being added into the reaction mixture containing the substrates. Then, lysozyme was also added into the reaction mixture. Based on Figure 1, where would the resulting enzyme kinetics curve for this experiment fall? A. Above line 1 B. Below line 1 but above line 3 C. Below line 3 D. The same as line 1

D is correct. Be sure to read the question stem carefully! Inhibitor A is a strong acid (H3O+) and inhibitor B is a strong base (OH-). Since these inhibitors are mixed together before being added to the reaction mixture, they would simply neutralize each other and become water before having any effect at all. Thus, the enzyme kinetics would not be affected, and the curve would fall along line 1. B, C: These choices represent inhibited reactions, with rates lower than that of the uninhibited reaction. In reality, however, the two inhibitors would neutralize each other before being added to the substrate-containing mixture, and no inhibition will occur.

mechanical advantage formula

MA = output force/input force

A researcher hypothesizes that there is institutional discrimination, but no individual discrimination, at a particular organization. Which of the following options would allow the researcher to fully confirm this hypothesis? A. Compare the demographics of individuals hired at the organization with the demographics at similar organizations B. Compare the demographics of individuals hired by several hiring directors within the organization C. Neither A nor B D. Both A and B together

D is correct. Both A and B are required here. Method A could show that there is a difference between organizations with regard to hiring practices, which implies institutional discrimination. Method B could show that no individual discrimination is present. Since the hypothesis proposes that there is institutional discrimination and that there is no individual discrimination at the organization, both A and B are required to fully confirm (or reject) the hypothesis. C: Both A and B together would allow the researcher to confirm (or reject) his hypothesis.

Based upon the information provided in the passage, which of the following could be a cultural factor which impacts adolescent risky behavior? I. Culturally-based expectations II. Cultural response to onset of puberty III. Cultural taboos regarding alcohol use A. I only B. I and II only C. I and III only D. I, II, and III "Puberty impacts the way adolescents see themselves. Girls who believe they are overweight as they begin puberty might develop an eating disorder. Early onset of puberty in adolescence is associated with increased risky behaviors, such as substance abuse and unprotected sex."

D is correct. Check the Roman numerals (RNs) one at a time. RN I is in all of the answers, so do not bother assessing that option. For RN II, the second paragraph mentions that how a girl views herself during puberty can impact risk behavior. Cultural response can contribute to these views. Finally, for RN III, paragraphs four and five describes how peer groups and parental influence can impact behavior. Both of these factors can be reflections of cultural taboos.

If the DNA of a representative species from each of the major kingdoms was examined, the sequences coding for which of following would be expected to be most similar? A. Photosynthesis B. Cholesterol synthesis C. Protein modification D. DNA synthesis

D is correct. DNA sequences that are common among different species, phyla, or even kingdoms are called conserved sequences. Conserved sequences tend to remain that way due to the fact that they code for a vital function that is common among disparate species. A: Not all kingdoms utilize photosynthesis. B: Not all kingdoms engage in cholesterol synthesis. C: Protein modification is something that is quite unique to each phylum or even species, since it is one of the major ways in which species tailor protein function to their needs and create additional protein diversity from the limited set of genes they contain.

What type of control does siRNA exert on G6PD expression? A. Transcriptional control B. Promotion C. Repression D. Post-transcriptional control

D is correct. Due to its structure, siRNA is only able to bind to other RNA strands, not to DNA or protein. Therefore, it must interfere with gene expression after transcription has already occurred, but before translation. Specifically, it prevents the translation of mRNA corresponding to the target protein. A, B: These controls occur before transcription. In contrast, siRNA prevents mRNA from being translated. C: Repressors are defined as protein molecules that bind with DNA or RNA to prevent eventual translation of a protein. Therefore, siRNA is not technically a repressor.

According to the passage, what would be the most effective advertising scheme? A. Present the CS and US simultaneously. B. Present the CS and then the US. C. Present the US and then the CS. D. It cannot be determined from the information in the passage.

D is correct. Each study presented the stimuli in different orders. However, the methods were not compared, and therefore the ideal method cannot be determined. A: This is done in the second part of Study 1. However, we are given no information regarding its efficacy in comparison to the other orders in which the stimuli were presented.

Many elderly individuals struggle with the concept of death and dying. The Kübler-Ross model provides a series of stages that most people experience when facing the end of their life. Which of the following is the correct sequence of emotional stages from this model? A. Anger, denial, depression, acceptance, bargaining B. Denial, depression, bargaining, anger, acceptance C. Bargaining, anger, depression, denial, acceptance D. Denial, anger, bargaining, depression, acceptance

D is correct. For these stages, you can remember the acronym Death Always Brings Definite Acceptance. The stages are sequenced in the following order: denial, anger, bargaining, depression, and acceptance.

An outspoken skeptic and opponent of automatic writing attends multiple séances where a medium appears to successfully contact someone who has recently died. If the skeptic's views shift over time to view the practice as harmless entertainment, this evolution is best described by: A. subjective norms. B. a locus of control. C. cognitive dissonance. D. reciprocal determinism.

D is correct. Reciprocal determinism is the theory set forth by Albert Bandura that a person's behavior both influences and is influenced by personal factors and the environment. In this scenario, the skeptic does not believe in the supernatural power of a medium, but attends multiple séances where they may see evidence that could soften their views. It appears this behavior of attending séances, in conjunction with the social environment of others who attend the séances, caused the skeptic's views on supernatural phenomena to shift. A: Subjective norms refer to the perceived social pressure to engage or to not engage in a behavior. The question does not indicate that there is any undue pressure on the skeptic to participate in the séance. B: This describes the extent to which an individual believes he/she is in control of events that affect him/her. The skeptic may not believe that the medium has control over supernatural phenomena, but this does not explain the evolution of the skeptic's views. C: Cognitive dissonance is found when an individual has inconsistent beliefs or attitudes, especially when making behavioral decisions and during changes in attitude. For example, conflicts from inconsistencies may cause discomfort, leading to an alteration in one of the attitudes, beliefs or behaviors the individual holds in order to reduce the discomfort and restore balance. From the question stem evidence, it does not appear that the skeptic has changed their mind on the validity of séances, only that they now believe séances are harmless.

If a psychologist were to claim that the ideomotor effect is unconscious, Freudian psychologists could argue this effect resides in which components of the psychic apparatus? I. The id II. The ego III. The superego A. I only B. I and II only C. I and III only D. I, II, and III

D is correct. Since this is a Roman numeral (RN) question, we may be able to save time by working efficiently. The id, ego, and superego are the three parts of the psychic apparatus Sigmund Freud suggested in his structural model of the psyche. The id (RN I) includes basic human instinctual drives and, by definition, is unconscious, making RN I correct. However, you may have noticed that RN I appears in all four answer choices, meaning that it must be correct and we do not even need to evaluate it. This is a perfect example of working efficiently through a Roman numeral problem. Moving on to RN II, this is a tough one! While the ego operates primarily at the conscious and preconscious levels, it also contains unconscious elements. This is because both the ego and the superego evolved from the id, which is unconscious. The ego deals with the id's impulses as soon as an adequate response is found. Hence, RN II is correct. Finally, RN III is also correct; the superego forms the organized part of the personality structure and therefore is mostly (but not entirely) unconscious. The diagram below depicts the id, ego, and superego and the extent to which each is conscious, preconscious, and unconscious.

If elements in the same group of the periodic table tend to have similar chemical properties, which of the following is the most likely structure of hydrogen sulfide? A. Tetrahedral B. Trigonal planar C. Pyramidal D. Bent

D is correct. The formula for hydrogen sulfide is H2S. Sulfur is in Group 16, directly under oxygen, so the structure of hydrogen sulfide would be similar to that of water: bent. The Lewis dot structure of H2S also predicts a bent structure due to the presence of the two lone electron pairs on the sulfur atom. Water has a H-O-H angle that is slightly less than the idealized tetrahedral angle of 109° due to the fact that the lone pairs occupy more space around the oxygen atom than do the bonding pairs. The sulfur lone pairs occupy even more space, and the H-S-H angle is around 92°, as shown below.

A surgeon suspects that the supernatural ability of a dowser to locate a hot coal buried in the ground is best explained by the presence of particularly sensitive thermoreceptors in their hands. Lesioning which area of the brain would best allow the surgeon to test her hypothesis? A. Lateral geniculate nucleus B. Hippocampus C. Frontal lobe D. Parietal lobe

D is correct. The parietal lobe integrates multiple inputs of sensory information, from spatial sense and navigation (proprioception) to temperature (thermoreceptors) and touch (mechanoreceptors). Lesioning this area of the brain would likely interfere with the dowser's ability to detect hot objects, if this were the true basis of the ability. A: The lateral geniculate nucleus is a visual information relay center in the thalamus. The LGN detects and interprets information from the retina and passes it on to the primary visual cortex in the occipital lobe.

Following extraction into chloroform, the spectrophotometric absorbance at 820 nm of copper in aqueous solution will be greatest at which pH? The passage states that spectrophotometric absorbance is used to measure the concentration of metal ion remaining in aqueous solution following extraction. This value should be maximized when the extent of the extraction is minimized A. 5.45 B. 5.35 C. 5.25 D. 5.15

D is correct. The passage states that spectrophotometric absorbance is used to measure the concentration of metal ion remaining in aqueous solution following extraction. This value should be maximized when the extent of the extraction is minimized. In Figure 2, this should correspond to the aqueous solution pH in which log D is smallest for the extraction in chloroform. Of those pH values given as answer choices, log D is smallest at pH 5.15. A: This answer choice is tempting, but it fails to account for the fact that the absorption of copper into aqueous solution will be greatest when the least amount of it has been extracted into chloroform.

Which neurotransmitter is primarily responsible for the generation of behaviors observed during dowsing? A. Dopamine B. Serotonin C. GABA D. Acetylcholine

D is correct. This question is fairly straightforward, so we should predict an answer before evaluating the choices. The passage describes the response as characterized by movements of the skeletal muscle (writing, dowsing), which is primarily carried out by the actions of acetylcholine released at the neuromuscular junction. The neuromuscular junction, or NMJ, is the synapse that separates a motor neuron and a muscle fiber. This synapse is pictured below. Inside the motor neuron are vesicles that contain neurotransmitter (specifically, acetylcholine) molecules. These vesicles can fuse with the axonal membrane in a calcium-dependent manner to release acetylcholine into the synapse. Binding of acetylcholine to receptors on the muscle fiber membrane initiates the contraction process. C: GABA is the chief inhibitory neurotransmitter in the nervous system, and generally is not highly involved in skeletal muscle movement.

While the composition of oxygen and nitrogen in air does not change with altitude, the decreasing temperature at high altitude does change the percent of air that is composed of H2O. Assuming constant relative humidity, which of the following can be asserted about the total grams of H2O in a given volume of air at 3000 m above sea level versus at sea level? A. Assuming constant relative humidity means that air has roughly the same mass of H2O per unit volume at 3000 m above sea level. B. Whether air at very high altitude has more or less mass of H2O per unit volume than it does at sea level depends on the temperature at high altitude. C. Air has significantly more mass of H2O per unit volume at 3000 m above sea level. D. Air has significantly less mass of H2O per unit volume at 3000 m above sea level.

D is correct. With decreasing temperature, air is able to hold less H2O. Since colder air can hold less total H2O, this means the same relative humidity would result in less total water in the air. For example, if warm air could hold 100 g of water in a given volume, then 50% relative humidity would be 50 g of water in the air. And if cold air could only hold 40 g of water in the same given volume, then 50% relative humidity would be 20 g of water in the air. So with the same relative humidity, the cold high-altitude air has less mass of water. A, C: These are false since the solubility of water in air decreases with decreasing temperature. B: The question itself tells us that high-altitude air is colder. Since the question is only asking us to draw a comparison, we don't need to know the exact temperature — just that it's colder than sea-level air.

Which of the following most closely approximates the pKa of phenolphthalein? A. 2.4 B. 4.8 C. 6 D. 9.3 The acidity of each broth sample was evaluated by acid-base titration with a standardized solution of 0.1 N sodium hydroxide, using phenolphthalein as an indicator. The acetic acid content of the fermentation products was measured 24, 48, and 72 hours after inoculation and reported as titratable acidity

D. 9.3 recognize that acetic acid and NaOH mixture would have a pH above 7. D is correct. Indicators function in acid-base titrations to identify, via color change or a similar mechanism, that an expected pH, and thus the titration endpoint, has been reached. In order to function in this way, an indicator must undergo a color change near the desired pH. This typically occurs because of a reversible change in the protonation state of the indicator. It is desirable then that the pKa of a chosen indicator be within ±1 unit of the target pH. For the titrations performed in the study of acetic acid, a weak acid, and sodium hydroxide, a strong base, the endpoint of the titration will occur at a pH greater than 7. Of the possible pKa values given as answer choices, only D could function well as an indicator for a pH in this range. A, B, C: These pKa values would be too low to serve as an indicator for a solution with a pH greater than 7.

Which of the following phase changes are exothermic processes? I. Liquid to gas II. Liquid to solid III. Gas to solid A. I only B. II only C. I and III only D. II and III only

D. II and III only D is correct. This question tests your understanding of reaction enthalpies. Reactions that proceed from solid to liquid to gas are endothermic reactions, since gases have more heat energy than liquids and liquids have more heat energy than solids. On the other hand, reactions that proceed from gas to liquid to solid release heat, making them exothermic reactions. Thus, II and III are both exothermic reactions, while I is an endothermic reaction.

Of the following theories, which provides the most applicable explanation for why some individuals interpret stigma negatively while others do not view stigma this way? A. The James-Lange theory of emotion B. The Cannon-Bard theory of emotion C. The Darwinian theory of emotion D. The cognitive appraisal theory of emotion

D. The cognitive appraisal theory of emotion D is correct. In the cognitive appraisal theory of emotion, individuals make different interpretations about stimuli, such as interpreting stigma negatively or non-negatively.

hydrogen sulfide

H2S Sulfide (British English sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions

suicide inhibition

Irreversible enzyme inhibitor Enzyme binds inhibitor (substrate analog) forming an irreversible complex thru covalent bond during normal catalysis rxn. Binds to active site.

Finding concentration or volume of acid/base titrations

NaVa = NbVb, where N and V are the normality (mol/L) and volume of the acidic and basic solutions, respectively. It is important to convert from molarity (M) to normality (N) for polyprotic acids and polyvalent bases.

hese are all modifications to amino acids and/or proteins. Protein modifications must be post-translational modifications. Such modifications can take place in a variety of locations within the cell, such as the interior of the endoplasmic reticulum or the cytoplasm. In contrast, post-transcriptional modifications (those performed on mRNA) occur in the nucleus; these include the addition of the poly(A) tail, the addition of the 5' cap, and splicing.

Post-transcriptional modifications are carried out entirely within the nucleus

Amines

R-NH2

Thioether

R-S-R

Thiol

R-SH

substrate analog

Substrate analogs (substrate state analogues), are chemical compounds with a chemical structure that resemble the substrate molecule in an enzyme-catalyzed chemical reaction. Substrate analogs can act as competitive inhibitors of an enzymatic reaction. If using substrate analogs on an inhibitor, it will decrease the activity of the inhibitor, and result in a higher function of the product relative to control.

There are no viable autosomal monosomies, and the only viable autosomal trisomies you should know are ______

Trisomy 21, 18, and 13

homotropic regulation

The sigmoidal shape of the curve implies that as each oxygen molecule binds to Hb, the affinity of Hb for oxygen goes up. Homotropic regulation is when a molecule serves as a substrate for its target enzyme, as well as a regulatory molecule of the enzyme's activity. O2 is a homotropic allosteric modulator of hemoglobin. The four subunits of hemoglobin actually bind to oxygen cooperatively, meaning the binding of oxygen to one of the four subunits will increase the likelihood that the remaining sites will bind with oxygen as well. when the substrate of an enzyme also regulates its activity (Ex: O2 is a homotropic allosteric modulatorof Hb)

nucleus accumbens,

a center for reward sensitivity that is often implicated in addiction research.

Northern blotting

combines gel electrophoresis of mRNA followed by hybridization with a probe on a membrane to find RNA sequences

A case control design

compares individuals with a disease to individuals without a disease.

We could add a strong base (for example, NaOH), which would ____________.

deprotonate

Attrition bias

is when participants drop out of a study over time, which affects the results.

ATP to ADP + Pi is __________ (oxidation or reduction)

reduction; ADP is the reduced form. This is due to the change in the oxidation state. Even though the charge is not changing, the oxidation state decreases. ADP + Pi to ATP is oxidation

A higher Ka is associated with _________ acidity.

stronger

The smaller the value of pKa, the stronger the acid. Weak acids have a pKa ranging from 2-14.

the higher the Ka, the stronger the acid

Normality

the number of equivalents of a substance dissolved in a liter of solution

Cannon-Bard Theory

the theory that an emotion-arousing stimulus simultaneously triggers (1) physiological responses and (2) the subjective experience of emotion

Cognitive Appraisal Theory

theory of emotion which theorizes that individuals decide on an appropriate emotion following the event

Next Step 2

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