AP Psychology — Unit 1: Biological Bases of Behavior

What AP Psychology Unit 1 covers

The College Board Course and Exam Description breaks Unit 1 into 6 topics:

1. 1.1 Interaction of Heredity and Environment
2. 1.2 The Nervous System
3. 1.3 The Endocrine System
4. 1.4 Brain Structure and Function
5. 1.5 Sensation
6. 1.6 Perception

AP Psychology Unit 1 practice questions

• Identical twins raised in completely different households still end up with very similar IQ scores. What does this tell us about intelligence?

  Heredity plays a major role; genetics strongly shape intelligence. That holds even when environments differ greatly.

• A geneticist suspects depression runs in families and wants to pin down how much is genes versus upbringing. Her first study compares how often identical vs. fraternal twins both have it; her second traces the trait down through generations of blood relatives. What are these two designs called?

  Twin study and family/pedigree study. Both estimate heritability via degrees of genetic relatedness.

• A child raised in poverty scores lower on cognitive tests than her genetically identical twin raised by a wealthy family. What does this reveal about the nature-nurture relationship?

  Environment can either suppress or enhance genetic potential. Genes set a reaction range; environment places you within it.

• Someone severs their spinal cord but their brain is undamaged. Which part of the nervous system is disrupted, and what functions are lost?

  The central nervous system is disrupted; the spinal cord is part of the CNS. Damage cuts brain-body communication below the injury.

• You're about to give a speech and your heart races, palms sweat, and pupils dilate — even though you haven't moved yet. Which nervous system branch is responsible?

  The sympathetic nervous system, which triggers fight-or-flight. It readies the body for action under threat or stress.

• After a near-accident, your heart rate slows, digestion resumes, and your breathing returns to normal. Which nervous system division is now dominant?

  The parasympathetic nervous system, which restores a calm state. It takes over after the fight-or-flight response subsides.

• Your immune system attacks the fatty insulation wrapped around your nerve fibers. Signals start misfiring, but the fibers themselves are fine. What are the two cell types: the signal-carrier and the one whose insulation is under attack?

  Neurons and glial cells. Neurons carry signals; glia make the myelin attacked in MS.

• A neuron reaches its threshold — then fires at full strength regardless of whether the stimulus was barely over threshold or massively over it. What principle does this demonstrate?

  The all-or-none principle — a neuron fires at full strength or not at all. Stimulus strength above threshold doesn't change firing strength.

+ 27 more AP Psychology cards in the app.

Key terms in Unit 1

These 12 terms show up in the Unit 1 cards. Each one links to its definition in the AP Psychology key-term reference.

• All-or-none principle
• Central nervous system
• Dopamine hypothesis
• Gate control theory
• Just-noticeable difference
• Monocular depth cues
• Opponent-process theory
• Parasympathetic nervous system
• Peripheral nervous system
• Sensory interaction
• Split-brain research
• Sympathetic nervous system