Princeton Review MCAT Practice Test
Questions and Correct Answers Updated
Question 1
Dynamical systems theory is concerned with finding qualitative solutions to
mathematical questions involving complex dynamic systems, which involve a fixed or
iterative time-dependent equation that describes the evolution of the system over
time. Two fundamental principles contribute to the difficulty of predicting the
evolution of complex systems: emergence and sensitivity to initial conditions.
Emergence describes the way that a system composed of many separate elements
combines these elements in such a way that the system itself is more complex than
the constituent elements themselves. Sensitivity to initial conditions, popularly known
as the butterfly effect, postulates that even seemingly slight changes to early states of
a complex system can lead to radically different qualitative states as the system
evolves over time.
How could the James-Lange theory of emotion best be explained by the dynamical
systems theory concept of emergence?
A. Perception of the emotional stimulus is determinative for the emotional experience.
B. Different collections of physiological markers combine to represent distinct
emotions.
C. Convergence of perceptive stimuli onto the thalamic and hypothalamic structures
creates a global emotional experience.
D. Cognition and physiology combine to create a more complex emotional
experience than the constituent components.
Correct Answer
B. Different collections of physiological markers combine to represent distinct
emotions.
Emergence, according to the passage, describes the way that a system composed of
many separate elements combines these elements in such a way that the system
itself is more complex than the constituent elements themselves. Since the James-
Lange theory deals with the way different physiological states represent emotions,
this theory of emotion could be explained by the dynamic systems concept of
emergence if different collections of physiological markers combine to represent
distinct emotions (choice B is correct). Perception of the emotional stimulus being
determinative does not bring together different constituent elements, as in the
definition of emergence, but is more similar to sensitivity to initial conditions
(choice A is wrong). Convergence onto thalamic and hypothalamic structures is
prominent in the Cannon-Bard theory, not the James-Lange theory (choice C is
Page 1 of 107
, wrong). The way that cognition and physiology combine during emotion is a central
component of the Schachter-Singer, or two-factor, theory of emotion (choice D is
wrong).
Question 2
Wives with more positive predictions (e.g., expected improvements in relationship
quality) reported higher levels of external stress and physical aggression. Therefore, it
was suggested that these predictions might be affected by individual perceptions of
risk factors in the relationship. For example, when women are facing stressful
circumstances, positively-biased cognitive processes might be used to regulate
contextual risks. Furthermore, results indicated that women with higher levels of
external stress also reported significantly greater declines in relationship satisfaction
in the measured timeframe following marriage. For both correlations, there were no
significant findings among the male participants.
Attribution is a concept that addresses how individuals view behavior, both our own
behavior and that of others. In the process of reasoning about behavior, there are
often errors. The findings discussed in the passage suggest a(n):
A. self-serving bias.
B. optimism bias.
C. just-world phenomenon.
D. actor-observer bias.
Correct Answer
B. optimism bias.
According to the passage (paragraph 4), the participants who had more positive
predictions for the future of their relationship also reported higher levels of physical
aggression. The fact that these participants maintain positive expectations for their
relationship despite the presence of problematic behaviors suggests the presence
of an attribution bias. The optimism bias describes the belief that bad things will not
happen to oneself in the future. This can be applied to the finding that people
continue to predict positive changes in their relationship, as opposed to divorce,
even in the presence of, for example, aggression (B is correct). The self-serving bias
describes the attribution of positive experiences to one's own character and actions
but negative experiences to factors external to one's own character and actions (A is
wrong). The just-world phenomenon describes the belief that the world is fair;
success or failure is the result of positive or negative behavior, respectively (C is
wrong). The actor-observer bias describes the belief that one's actions are
situational while the actions of others are the direct result of their personalities (D is
wrong)
Page 2 of 107
,Question 3
Ghrelin, the "hunger hormone," is released when the stomach is empty. It increases
hunger and promotes secretion and motility in the digestive tract. The receptor for
ghrelin is found on the same cells in the brain as the receptor for leptin. Which of the
following is a true statement?
A. The interaction of leptin and ghrelin can be considered competitive inhibition
because they produce antagonistic effects.
B. The interaction of leptin and ghrelin is considered to be allosteric inhibition.
C. The interaction of leptin and ghrelin is considered uncompetitive because ghrelin
only binds when leptin is already bound.
D. There is no interaction between leptin and ghrelin because they operate on
separate receptors.
Correct Answer
Even though they bind to the same cells in the brain, the fact that leptin and ghrelin
bind to separate receptors means that there cannot be any kind of inhibition or
interaction between them (D is correct). For competitive inhibition to occur, two
things must be trying to bind to one site on the same receptor. The fact that they
have separate receptors prevents this (A is wrong). Likewise, allosteric inhibition
requires that the inhibitor bind to a separate site on the same enzyme or receptor
(B is wrong), and there is nothing in the question stem or passage to suggest that
ghrelin can only bind when leptin is bound (C is wrong).
Page 3 of 107
, Question 4
Aldosterone binds to an intracellular protein receptor, inducing an allosteric change
which enables this protein to bind DNA and promote the transcription of the Na+/K+
ATPase gene. An activated aldosterone receptor most directly regulates activity of
which of the following enzymes?
A. DNA polymerase
B. RNA polymerase II
C. Na+/K+ ATPase
D. Renin
Correct Answer
B. RNA polymerase II
Aldosterone binds aldosterone receptors to regulate transcription of a specific set
of genes. The enzyme that synthesizes mRNA is RNA polymerase II, so it is this
enzyme that would be most directly affected by the activated aldosterone receptor
(B is correct). DNA polymerase is used in replication, not transcription (A is
incorrect), and while aldosterone may ultimately affect the activity of the Na+/K+
ATPase and renin, these would be indirect effects (C and D are incorrect).
Page 4 of 107
Questions and Correct Answers Updated
Question 1
Dynamical systems theory is concerned with finding qualitative solutions to
mathematical questions involving complex dynamic systems, which involve a fixed or
iterative time-dependent equation that describes the evolution of the system over
time. Two fundamental principles contribute to the difficulty of predicting the
evolution of complex systems: emergence and sensitivity to initial conditions.
Emergence describes the way that a system composed of many separate elements
combines these elements in such a way that the system itself is more complex than
the constituent elements themselves. Sensitivity to initial conditions, popularly known
as the butterfly effect, postulates that even seemingly slight changes to early states of
a complex system can lead to radically different qualitative states as the system
evolves over time.
How could the James-Lange theory of emotion best be explained by the dynamical
systems theory concept of emergence?
A. Perception of the emotional stimulus is determinative for the emotional experience.
B. Different collections of physiological markers combine to represent distinct
emotions.
C. Convergence of perceptive stimuli onto the thalamic and hypothalamic structures
creates a global emotional experience.
D. Cognition and physiology combine to create a more complex emotional
experience than the constituent components.
Correct Answer
B. Different collections of physiological markers combine to represent distinct
emotions.
Emergence, according to the passage, describes the way that a system composed of
many separate elements combines these elements in such a way that the system
itself is more complex than the constituent elements themselves. Since the James-
Lange theory deals with the way different physiological states represent emotions,
this theory of emotion could be explained by the dynamic systems concept of
emergence if different collections of physiological markers combine to represent
distinct emotions (choice B is correct). Perception of the emotional stimulus being
determinative does not bring together different constituent elements, as in the
definition of emergence, but is more similar to sensitivity to initial conditions
(choice A is wrong). Convergence onto thalamic and hypothalamic structures is
prominent in the Cannon-Bard theory, not the James-Lange theory (choice C is
Page 1 of 107
, wrong). The way that cognition and physiology combine during emotion is a central
component of the Schachter-Singer, or two-factor, theory of emotion (choice D is
wrong).
Question 2
Wives with more positive predictions (e.g., expected improvements in relationship
quality) reported higher levels of external stress and physical aggression. Therefore, it
was suggested that these predictions might be affected by individual perceptions of
risk factors in the relationship. For example, when women are facing stressful
circumstances, positively-biased cognitive processes might be used to regulate
contextual risks. Furthermore, results indicated that women with higher levels of
external stress also reported significantly greater declines in relationship satisfaction
in the measured timeframe following marriage. For both correlations, there were no
significant findings among the male participants.
Attribution is a concept that addresses how individuals view behavior, both our own
behavior and that of others. In the process of reasoning about behavior, there are
often errors. The findings discussed in the passage suggest a(n):
A. self-serving bias.
B. optimism bias.
C. just-world phenomenon.
D. actor-observer bias.
Correct Answer
B. optimism bias.
According to the passage (paragraph 4), the participants who had more positive
predictions for the future of their relationship also reported higher levels of physical
aggression. The fact that these participants maintain positive expectations for their
relationship despite the presence of problematic behaviors suggests the presence
of an attribution bias. The optimism bias describes the belief that bad things will not
happen to oneself in the future. This can be applied to the finding that people
continue to predict positive changes in their relationship, as opposed to divorce,
even in the presence of, for example, aggression (B is correct). The self-serving bias
describes the attribution of positive experiences to one's own character and actions
but negative experiences to factors external to one's own character and actions (A is
wrong). The just-world phenomenon describes the belief that the world is fair;
success or failure is the result of positive or negative behavior, respectively (C is
wrong). The actor-observer bias describes the belief that one's actions are
situational while the actions of others are the direct result of their personalities (D is
wrong)
Page 2 of 107
,Question 3
Ghrelin, the "hunger hormone," is released when the stomach is empty. It increases
hunger and promotes secretion and motility in the digestive tract. The receptor for
ghrelin is found on the same cells in the brain as the receptor for leptin. Which of the
following is a true statement?
A. The interaction of leptin and ghrelin can be considered competitive inhibition
because they produce antagonistic effects.
B. The interaction of leptin and ghrelin is considered to be allosteric inhibition.
C. The interaction of leptin and ghrelin is considered uncompetitive because ghrelin
only binds when leptin is already bound.
D. There is no interaction between leptin and ghrelin because they operate on
separate receptors.
Correct Answer
Even though they bind to the same cells in the brain, the fact that leptin and ghrelin
bind to separate receptors means that there cannot be any kind of inhibition or
interaction between them (D is correct). For competitive inhibition to occur, two
things must be trying to bind to one site on the same receptor. The fact that they
have separate receptors prevents this (A is wrong). Likewise, allosteric inhibition
requires that the inhibitor bind to a separate site on the same enzyme or receptor
(B is wrong), and there is nothing in the question stem or passage to suggest that
ghrelin can only bind when leptin is bound (C is wrong).
Page 3 of 107
, Question 4
Aldosterone binds to an intracellular protein receptor, inducing an allosteric change
which enables this protein to bind DNA and promote the transcription of the Na+/K+
ATPase gene. An activated aldosterone receptor most directly regulates activity of
which of the following enzymes?
A. DNA polymerase
B. RNA polymerase II
C. Na+/K+ ATPase
D. Renin
Correct Answer
B. RNA polymerase II
Aldosterone binds aldosterone receptors to regulate transcription of a specific set
of genes. The enzyme that synthesizes mRNA is RNA polymerase II, so it is this
enzyme that would be most directly affected by the activated aldosterone receptor
(B is correct). DNA polymerase is used in replication, not transcription (A is
incorrect), and while aldosterone may ultimately affect the activity of the Na+/K+
ATPase and renin, these would be indirect effects (C and D are incorrect).
Page 4 of 107
