AP Psychology Unit 1: Biological Bases of Behavior Practice Exam

1. [Skill: 2.A | Topic: 1.1] A behavioral geneticist is studying the role of heredity and environment in major depressive disorder (MDD). The researcher reports the following concordance rates (the likelihood that both individuals show MDD): - Monozygotic (identical) twins reared together: 0.60 - Monozygotic (identical) twins reared apart: 0.50 - Dizygotic (fraternal) twins reared together: 0.30 - Adoptive siblings reared together (not genetically related): 0.10 Which of the following conclusions is best supported by the data?

2. [Skill: 3.A | Topic: 1.1] A pediatrician explains to parents that their infant tested positive for a gene associated with phenylketonuria (PKU). Without treatment, PKU can lead to severe cognitive impairment. However, if the child follows a strict low-phenylalanine diet beginning early in life, typical cognitive development is expected. Which statement best illustrates the relationship between heredity and environment described in the scenario?

3. [Skill: 1.A | Topic: 1.1] Researchers report that across many cultures, young children show rapid attention to stimuli that resemble snakes or spiders, even when they have had little direct experience with these animals. The researchers propose that this pattern reflects an evolved tendency. Which explanation best reflects the evolutionary perspective described by the researchers?

4. **1.** [Skill: 1A | Topic: 1.2] A hospital report states: “The patient sustained damage to neural tissue located within the vertebral column. The injury interfered with transmission of information between the brain and the rest of the body.” Which of the following best identifies the affected structure and explains why it is classified within the central nervous system (CNS)?

5. **2.** [Skill: 2A | Topic: 1.2] A student in a physiology lab observes two responses in a participant: - Response 1: The participant chooses to lift a hand when instructed. - Response 2: The participant’s digestion slows during a stressful countdown task. Which option correctly matches each response to the appropriate subsystem of the peripheral nervous system (PNS)?

6. **3.** [Skill: 2A | Topic: 1.2] A person walking alone at night hears footsteps behind them. Within seconds, their heart rate increases and their pupils dilate. A few minutes later, after realizing the sound was harmless, their breathing slows and digestion returns to typical levels. Which of the following best explains the nervous system activity described?

7. [Skill: 1B | Topic: 1.3] A student accidentally touches a hot pan and immediately jerks their hand away before consciously feeling pain. In a class demonstration, the teacher explains that the response is produced by a spinal reflex arc. Which of the following best describes the correct sequence of neural communication in the reflex arc that produces the rapid withdrawal?

8. [Skill: 2A | Topic: 1.3] A researcher records the membrane potential of a neuron while delivering two brief electrical stimuli. The first stimulus causes the neuron to fire an action potential. The second stimulus is delivered 2 milliseconds later, but the neuron does not fire a second action potential. Which of the following best explains why the second stimulus fails to trigger another action potential?

9. [Skill: 1C | Topic: 1.3] A lab study compares participants who receive cocaine with participants who receive a placebo. Compared to the placebo group, the cocaine group reports increased energy and euphoria. The researchers conclude the drug increases the availability of dopamine in synapses in reward-related brain circuits. Which mechanism best supports the researchers’ conclusion?

10. [Skill: 3A | Topic: 1.4] A neurologist is evaluating a patient who recently experienced a small stroke. The patient reports that they can understand spoken instructions and can move their arms and legs with normal strength, but they have difficulty maintaining balance while standing and their movements (e.g., reaching for a cup) appear jerky and poorly timed. Brain imaging shows localized damage to a structure at the back of the brain. Which of the following brain structures was most likely damaged?

11. [Skill: 4A | Topic: 1.4] In a split-brain study, a participant has had the corpus callosum severed to reduce severe seizures. During a lab task, the researcher briefly flashes the word “KEY” to the participant’s left visual field while the participant fixates on a central point. Immediately afterward, the participant is asked to say what word was shown and then is asked to select the matching object from a set of items using either hand. Which of the following outcomes is most consistent with split-brain research and typical hemispheric specialization?