AAMC Practice Material

Question 1

T/F: Some Na+ can permeate through an axon at nodes of Ranvier (because they are not myelinated) but these do not contribute to action potentials and are not a result of the sodium potassium pump

Answer 1

true

Question 2

T/F: action potentials along a neuron cause increased permeability of the plasma membrane

Answer 2

True, by the opening of voltage gate channels??

Question 3

Answer 3

Question 4

the main means of water loss through the skin is

Answer 4

raising external temperature to keep normal body temperature

Question 5

What is the role of the plasmid in bacterial reproduction and what are the 3 ways that bacteria can reproduce? What is the F plasmid and what reproductive process relies on the F plasmid?

Answer 5

Question 6

Inflation of the lungs in mammals is accomplished by

Answer 6

Question 7

Which of the following lipids is a key component of myelin sheaths?

A. Terpenes

B. Sphingolipids

C. Prostaglandins

D. Tocopherols

Answer 7

Sphingomyelin, a type of sphingolipid, is an important lipid component in the myelin sheath of nerve cell axons (choice B is correct). The other compounds do not play an important role in myelin (choices A, C, and D are incorrect).

Question 8

The urea cycle occurs primarily in what part of the human body?

Answer 8

human liver, the site of most amino acid catabolism (elements of the urea cycle also take place in the kidneys;

Question 9

What energy does ATP synthase use directly in order to catalyze the formation of ATP from ADP and inorganic phosphate?

A. The energy of the proton gradient generated by the electron transport chain

B. The energy released by the hydrolysis of GTP

C. The energy released via coupling of ATP synthase to substrate-level phosphorylation

D. The energy of the conformational change induced by binding of ADP and inorganic phosphate to ATP synthase’s catalytic domain

Answer 9

A. The energy of the proton gradient generated by the electron transport chain

that’s because ATP synthase is only in the mitchondria/electron transport chain

Question 10

If a drug inhibited the activity of the Na+/K+ ATPase in neurons, this would result in:

A. increased cellular glucose uptake via secondary active transport.

B. increased cellular glucose uptake via primary active transport.

C. decreased cellular glucose uptake via primary active transport.

D. decreased cellular glucose uptake via secondary active transport.

Answer 10

D. decreased cellular glucose uptake via secondary active transport.

The Na+/K+ ATPase is used to generate a Na+ gradient which is then used for glucose uptake by cells via secondary active transport (choices B and C are wrong). Uptake of glucose is mediated by the Na+-glucose cotransporter. Inhibiting the Na+/K+ ATPase would destroy the Na+ gradient and in turn decrease glucose uptake

Question 11

Which one of the materials listed in Table 1 will produce visible light of the shortest wavelength?

A. Barium nitrate

B. Cryolite (Na3AlF6)

C. Copper sulfate

D. Strontium nitrate

Answer 11

C. Copper sulfate (blue light has highest frequency on list so shortest wavelength)

Question 12

Question 49

When an oxidizer and fuel react together to produce an explosion, the resulting sound waves are:

A. longitudinal, causing air molecules to move perpendicular to the direction of wave propagation.

B. longitudinal, causing air molecules to move parallel to the direction of wave propagation.

C. transverse, causing air molecules to move perpendicular to the direction of wave propagation.

D. transverse, causing air molecules to move parallel to the direction of wave propagation.

Answer 12

B. Sound waves are longitudinal, which means that the air molecules oscillate in the direction parallel to the direction of wave propagation.

Question 13

All of the following are expected to increase the activity of the pyruvate dehydrogenase complex (PDC) EXCEPT high:

A. [NAD+].

B. [CoA].

C. [AMP].

D. [ATP].

Answer 13

D. The pyruvate dehydrogenase complex catalyzes the conversion of pyruvate to acetyl-CoA, with the ultimate goal of increasing ATP production. Therefore, high levels of ATP negatively feedback on the activity of this enzyme (choice D would not increase the activity of the PDC and is the correct answer choice). NAD+, CoA, and AMP would stimulate the activity of the PDC since their levels are higher when ATP levels are low (choices A, B, and C would increase the activity of PDC and can be eliminated).

Question 14

T/F: In trans-1,3-disubstituted cyclohexanes, one substituent will always be axial and one equatorial;

Answer 14

true

Question 15

What are the most likely patterns of inheritance for CF and achondroplasia?

A. CF: X-linked recessive
Achondroplasia: autosomal dominant

B. CF: autosomal dominant
Achondroplasia: autosomal recessive

C. CF: spontaneous mutation only
Achondroplasia: X-linked recessive

D. CF: autosomal recessive
Achondroplasia: autosomal dominant

Answer 15

D. CF: autosomal recessive
Achondroplasia: autosomal dominant

Remember to answer the three basic questions before tackling any pedigree problem, and remember that in pedigrees showing two different conditions, the three questions must be answered separately for each condition. First, is the condition/disease caused by a dominant allele or a recessive allele? If the disease skips generations it is most likely recessive. Based on this, we can conclude that CF is recessive and achondroplasia is dominant (choices B and C are wrong). Second, is the disease allele carried on an autosome or on one of the sex chromosomes? If significantly more men than women are affected, the disease is most likely sex-linked. Based on the pedigree, we can conclude that both CF and achondroplasia are autosomal (choice D is correct and A is wrong). Since both conditions are autosomal, the third question (“If sex-linked, is the disease carried on the X chromosome or the Y chromosome?”) is irrelevant and unnecessary in this case.

Question 16

T/F: damage to exocrine tissue within the pancreas may hinder the secretion of lipases.

Answer 16

true

Question 17

A solution is prepared conataining 450 grams of NaI in enough water to create a 2 L solution. What is the molarity of this solution?

A. 1.5 M

B. 3 M

C. 6 M

D. 9 M

Answer 17

QUESTION EXPLANATION

A. Sodium iodide (NaI) has a molar/molecular mass of 23 (Na) + 127 (I) = 150 g/1 mol, so 450 g of NaI is 3 moles of NaI (450g/1 x 1 mole/150g=3moles). If this is dissolved in enough water to make a 2 L solution, then the concentration of NaI(aq) is [NaI] = 3 mol/2 L = 1.5 M

Question 18

Which of the following can be deduced about a ketotetrose with an absolute configuration of S?

A. It is a D sugar.

B. It is an L sugar.

C. It is levorotatory.

D. It is dextrorotatory.

Answer 18

S is L and

D is R

*unless the group opposite the hydroxyl of the highest priority chiral center is not priority higher than oxygen

Question 19

Which type of inheritance pattern is most consistent with increased phenotypic expression of a rare disease arising as a result of inbreeding within a population?

A. X-linked dominant

B. Autosomal dominant

C. Mitochondrial inheritance

D. Autosomal recessive

Answer 19

D. Autosomal recessive

Question 20

Ultrafiltration refers to

Answer 20

a type of membrane filtration in which forces like pressure or concentration gradients lead to a separation through a semipermeable membrane.

Question 21

T/F: osteocyte is another word for osteoclast

Answer 21

false!

An osteocyte is a mature bone cell that does not form or remodel bone, and therefore, osteocytic activity would have no influence on calcium homeostasis. wherease osteoclasts breakdown bone in order to release calcium into the blood for homeostasis

Question 22

In which of the following people would you expect an increase in PTH activity?

A. A person whose parathyroid glands have been removed

B. A person with increased osteoblastic activity

C. A person with increased osteocytic activity

D. A person with higher than normal urinary calcium concentration

Answer 22

B. A person with increased osteoblastic activity

because osteoblasts are reponsible for pulling calcium from the blood to form bone

Question 23

One of the ways in which RNA polymerase differs from DNA polymerase III is that RNA polymerase does/does not have exonuclease activity

Answer 23

RNA polymerase does not have exonuclease activity

Question 24

A proton gradient is most directly related to the functioning of:

A. the Na+/K+ ATPase.

B. the collecting ducts in the nephron.

C. voltage-gated calcium channels.

D. ATP synthase.

Answer 24

D. ATP synthase.

Proton gradients are established by the electron transport chain during aerobic respiration. The gradient is then used to power an ATP synthase (D is correct). The Na+/K+ ATPase hydrolyzes a molecule of ATP to move sodium and potassium against their concentration gradients (A is wrong), the collecting ducts in the nephron regulate osmotic balance of the body through interactions with ADH (B is wrong), and voltage-gated Ca2+ channels are regulated by voltage, not proton gradients (C is wron

Question 25

what does a pedigree of X linked recessive trait look like?

Answer 25

notice that whether the mutation is X linked or Y linked, males will be disproportionately affected because in either case they’re only getting one non-mutated chromosome, wherease girls have a chance of getting one non-mutated (if its X linked) or none at all (if Y linked)

Question 26

A couple comes to you for genetic counseling. They are considering having children, but the man is colorblind and a hemophiliac (both X-linked recessive traits). The woman does not have relatives with either disease. The couple wants to know how likely it is that they will have a child with either disease. What should be your response?

A. There is a 50% chance that they will have a child with both diseases.

B. There is a 25% chance that they will have a child with one of the two diseases.

C. There is a 25% chance that, if they have a son, he will have both diseases.

D. There is essentially no chance that they will have a child with either disease.

Answer 26

D. There is essentially no chance that they will have a child with either disease.

you don’t need to draw a punnet square to solve. Just visualize the fact that since the X chromosome is coming from the mom, theres no chance that the son will get any of the mutated Xs from dad

Question 27

During times of abundant energy, ATP acts as a:

A. positive feedback regulator by stimulating the activity of PFK.

B. negative feedback regulator by inhibiting the activity of PFK.

C. competitive inhibitor by inhibiting the activity of PFK.

D. noncompetitive inhibitor by stimulating the activity of PFK.

Answer 27

B. negative feedback regulator by inhibiting the activity of PFK.

reducing glycolysis products

Question 28

Decreased Fru-2,6-P2 in the hepatocytes will stimulate which of the following?

A. Gluconeogenesis

B. Glycolysis

C. Krebs cycle

D. Electron transport

Answer 28

A. Gluconeogenesis

Question 29

T/F: Glucagon is a peptide hormone that binds to cell surface receptors and activates second messenger systems, notably cAMP.

Answer 29

TRUE:

this means that it binds to cell surface receptors and not intracellular receptors (it cannot diffuse across the PM)

Question 30

It was discovered that all the viruses in an experiment were enveloped. A researcher hypothesized that this was the reason the viruses could not replicate in insect cells. Is the researcher’s hypothesis reasonable

A. Yes; the cell walls of the insect cells prevent an envelope from being acquired.

B. Yes; the insect exoskeleton prevents an envelope from being acquired.

C. No; insect walls are made of chitin.

D. No; insect cells do not possess a cell wall.

Answer 30

D. No; insect cells do not possess a cell wall.

A viral envelope is acquired as the virus exits its host cell by budding through the plasma membrane and becoming coated in lipid bilayer. Viruses are unable to bud from cells that possess a cell wall (such as bacteria or plants), thus those viruses cannot acquire an envelope. However, insects are members of Kingdom Animalia, and as such their cells do not possess a cell wall, so this could not be the reason for the inability of the viruses to replicate in these cells. (Do not confuse chitinous exoskeleton of insects with a cell wall.)

Question 31

T/F: Enveloped viruses are unable to replicate in cells that possess a cell wall (such as bacteria or plants).

Answer 31

True.

Plants are eukarytoes but have a cell wall like prokarytoes

Question 32

Crystallization separates solid compounds based on their ________

Answer 32

solubilities

Question 33

In a population of 10,000 people, how many carriers of XP are there given that XP is an autosomal recessive allel with a frequency of 1%

A. 99

B. 198

C. 900

D. 1,800

Answer 33

B. 198

You use the Hardy-Weinberg equation, where the number of carriers of a recessive allele is determined by the expression 2pq (from p² + 2pq + q²=1)

So, the frequency of the dominant non-disease expressing allele, p, is 0.99. Therefore, in a population of 10,000 people, the number of carriers would be 2(0.01)(0.99)(10000), or 198.

Question 34

T/F: Cognitive dissonance can be observed among people who engage in risky conduct despite knowing that it is dangerous and attempt to reduce the dissonance that they experience. A heterosexual woman who does not engage in safer sex may downplay her HIV risk by relying on the stereotype that HIV is most prevalent in the gay male community

Answer 34

True

Question 35

Internal validity vs external validity?

Answer 35

Internal validity refers to the extent to which a causal conclusion based upon an experiment is warranted; a study that lacks systematic error is said to have internal validity.

External validity refers to the extent to which the results of an experiment can be generalized to other situations and to other people.

Question 36

External validity vs Test-retest reliability

Answer 36

External validity refers to the extent to which the results of an experiment can be generalized to other situations and to other people.

Test-retest reliability applies to test scores and assesses the degree to which they are consistent from one administration to the next

Question 37

Test-retest reliability vs replicability

Answer 37

Test-retest reliability applies to test scores and assesses the degree to which they are consistent from one administration to the next

Replicability refers to the ability to obtain the same results under the same experimental conditions (it does not mean that the same experiment would produce the same results when applied to a slightly altered scenario)

Question 38

confounding variable vs participant variable

Answer 38

confounding variable is one that the experimenter does not intentionally manipulate but which may vary with the independent variable and thus confuse the results of the study.

participant variable is a type of extraneous (uncontrolled) variable that is related to the individual characteristics of the subjects.

Question 39

Yerkes-Dodson law refers to

Answer 39

how stress and arousal affect performance; a moderate level of stress helps people perform at their best (but only up to a point). It is categorized as social facilitation

Question 40

cultural capital refers to

Answer 40

certain non-financial assets that promote or allow upward mobility in society, such as education, social graces, proper speech, specialized attire,

Question 41

cultural capital vs social capital

Answer 41

cultural capital refers to certain non-financial assets that promote or allow upward mobility in society, such as education, social graces, proper speech, specialized attire,

Social capital refers to the benefits of belonging to social networks

Question 42

Symbolic capital refers to

Answer 42

certain intangible assets, such as prestige, honor, and recognition, that help one advance within a society

Question 43

The theorist most closely associated with structural functionalism is

Answer 43

Emile Durkheim

Question 44

Construct validity refers to

Answer 44

how well a test measures what it is expected to measure

Question 45

Split-half reliability refers to

Answer 45

a multiple-item instrument and how well parts of it assess what is being measured compared to the whole

Question 46

A token economy is a simple system of rewards for desirable behavior, which is one type of ___________ conditioning

Answer 46

operant

Question 47

The fundamental attribution error refers to

Answer 47

the tendency of people to attribute the negative behaviors of others to their core personalities, rather than to situational or circumstantial factors.

*don’t confuse with self-serving bias or the actor-observer effect

https://docs.google.com/document/d/14UB95HsbVzMwsD7BbtjH5EI19HD9VZ0s3PdIMA304a0/edit?disco=AAAABw4uc90

Question 48

there are three important systems that contribute to working memory, they are:

1. phonological loop
2. the episodic buffer
3. the visuospatial sketchpad

define each

Answer 48

the phonological loop is the system that is responsible for allowing us to repeat auditory information back to ourselves long enough in working memory to either write the information down or to somehow encode it into long-term memory;

The episodic buffer integrates information across domains;

the visuospatial sketchpad is the site for processing visual and spatial information in working memory

Question 49

T/F: Iconic sensory memory is not part of the working memory system

Answer 49

True

Question 50

Structural discrimination vs institutional discrimination;

Answer 50

Structural discrimination is similar to institutional discrimination; however, structural discrimination occurs when individuals who run the institutions in question do not intend to treat any group differently or unjustly, but inadvertently do so through their established practices

Question 51

intergenerational mobility vs social reproduction

Answer 51

intergenerational mobility occurs when there is a change in social class between parents and children within a family;

social reproduction occurs when structures and activities in place within a society serve to transmit and reinforce social inequality from one generation to the next. Cultural and social capital are two mechanisms by which social reproduction occurs.

Question 52

downward mobility vs intergenerational mobility

Answer 52

downward mobility describes a lowering in social class for an individual.

intergenerational mobility occurs when there is a change in social class between parents and children within a family

Question 53

T/F: A “punitive organization” is not one of the three formal organizations in sociology

Answer 53

true

don’t be tricked!

*prison is a coersive organization not a punitive one because membership is involuntary

Question 54

Dysthymic disorder vs Cyclothymic disorder

Answer 54

Dysthymic disorder, dysthmia (aka persistent depressive disorder) a less severe pattern of depression, is characterized by the sad mood, lack of interest, and loss of pleasure associated with major depression. These symptoms are milder but longer lasting. To qualify as a dysthymic disorder, the symptoms must last for at least two years in adults and one year in children

Cyclothymic disorder is a milder form of bipolar disorder and is characterized by an alternating pattern of mood swings (choice A is wrong).

Question 55

Anhedonia is defined as

Answer 55

the inability to feel pleasure.

Question 56

T/F: While serotonin dysregulation is associated with depressive symptoms, serotonin is not involved in reward processing

Answer 56

true

Question 57

Psychological drug dependence is characterized by

Answer 57

the use or abuse of the drug in response to painful emotional triggers, such as depression or anxiety

Question 58

Parallel processing describes the brain’s ability to

Answer 58

simultaneously process incoming stimuli of differing quality,

Question 59

Which of the following is/are true regarding Gestalt laws of perceptual organization?

1. Certain basic features of vision, including color and motion, are processed consciously in a bottom-up manner
2. In our visual field, we tend to group nearby objects together; this is known as “proximity”
3. When viewing something, we tend to fill in gaps in order to complete whole objects; this is known as “closure”

Answer 59

2 and 3 are gestalt principles

One of the Gestalt principles of grouping is that of proximity; we tend to group nearby figures or objects together. Another of the Gestalt principles of grouping is that of closure; we tend to fill in gaps in order to perceive objects that are whole and complete

Question 60

T/F: Comorbidity rates for this condition and DID are quite high.

Answer 60

TRUE

Borderline personality disorder involves a pervasive pattern of instability in self-image, mood, interpersonal relationships, and behavior. The striking similarities have led to the speculation that DID is actually a manifestation of borderline personality disorder in which the patient erroneously attributes his or her chronic instability to the existence of alternate personalities

Question 61

Shaping is an operant conditioning technique that involves

Answer 61

producing a desired behavior (in this case acceptance of the DID diagnosis) by reinforcing successive approximations of that behavior

Question 62

Aversive conditioning is a behavior modification technique that …

Answer 62

attempts to eliminate an unwanted behavior by pairing it with an unpleasant stimulus

Question 63

Conceptual salience refers to

Answer 63

the prominence of a word or object in one’s mental representations

Question 64

Dissociation is defined as a split in consciousness, and this phenomenon can allow contradictory thoughts or behaviors to occur simultaneously. In the case of a person reporting no pain but indicating otherwise, can dissociation explain this?

Answer 64

yes, dissociation might explain this behavior

Question 65

Vygotsky’s zone of proximal development refers to

Answer 65

the gap between what a student has already mastered and what he or she could master if provided with educational support.

Question 66

What does this represent and how do you interpret it?

Answer 66

it is a certain class of phase diagrams that displays the relationship between the predominate species of electrolyte and the combined factors that influence its predominate form: electric potential and pH. Demarcation lines indicate equilibrium between the species, where a horizontal line represents no change with pH at that voltage

Question 67

octahedral compounds have how many atoms covalently bonded?

Answer 67

octahedral compounds have 6 symmetrically bonded molecules (atoms, groups of atoms, or ligands) which form 8 symmetrical faces

Question 68

what does a mono-ester look like?

Answer 68

Question 69

what linkage does glycogen synthase perform?

Answer 69

the main chain bond in glycogen

Question 70

glycogen branching takes place via what type of bonds

Answer 70

alpha 1,6 glycosidic

Question 71

what will happen if a homogenous catalyst cannot be separated fromt he products at the end of a reaction

Answer 71

the products will be contaminated

Question 72

chemiosmosis refers to

Answer 72

selective transport of ions across a semipermeable membrane, down their electrochemical gradient.

this occurs during ETC when hydrogens travel down their concentration gradient through the ATP synthase to get the mechanism to work to produce ATP

Question 73

what characterizes steroid structure?

Answer 73

4 ring structure

Question 74

true/false “glomerular filtrate” refers to filtrate regardless of where it is in the kidney (not just at the glomerulus)

Answer 74

True

Question 75

what is a lipid raft

Answer 75

a section of the plasma membrane that is cholesterol rich and glycosphingolipids rich

Question 76

T/F: the hormone cascade regulation involves negative feedback which extends all the way up to the level of hypothalamus release of stimulating factors

Answer 76

true

Question 77

T/F: glucose is the main fuel for brain cells

Answer 77

True