The Biology of Behavior

A comprehensive set of practice Q&A flashcards covering genetics, the nervous system, neurons, brain regions, brain plasticity, and brain measurement methods.

What is behavioral genetics?

The scientific study of the role of heredity in behavior.

Why is the relationship between genes and behavior considered complex?

Usually many genes influence each trait; single genes can cause a specific trait or disease, but they play only a small part in creating a given behavior.

What does polygenic mean?

Many genes interact to create a single characteristic.

What does monogenic mean?

Traits determined by a single gene.

What is an example of a trait passed on by a single gene?

Lactose tolerance/intolerance.

What is heritability?

The extent to which a characteristic is influenced by genetics.

What do gene-by-environment studies examine?

Whether genes are correlated with a particular trait.

What is epigenetics?

Changes in how genes are turned on or off without changing the DNA sequence.

What structures compose the central nervous system (CNS)?

Brain and spinal cord.

What structures comprise the peripheral nervous system (PNS)?

All the nerve cells outside the CNS.

What is the function of the somatic nervous system?

Serves the skeletal muscles and carries sensory information to the CNS.

What does the autonomic nervous system (ANS) control?

Involuntary systems of the body such as organs and glands.

What is the sympathetic nervous system responsible for?

Activates bodily systems in emergencies; the fight-or-flight response.

What is the role of the parasympathetic nervous system?

Usually relaxes the body and returns it to a less active, restful state.

What are the main structural components of a neuron?

Soma (cell body with nucleus); Axon (transmits signals); Dendrites.

What is the function of the myelin sheath?

Insulates the axon to speed the neural impulse.

What is a synapse?

The gap where the axon meets a dendrite or cell body; site of neurotransmission.

What is an action potential?

The positively charged impulse that travels down the axon; follows the all-or-none principle.

What is the resting potential?

The electrical difference across the neuron's membrane when at rest.

What is the refractory period?

The time between an action potential and the neuron’s resting state.

What are the Nodes of Ranvier?

Gaps in the myelin sheath across which the action potential jumps.

What triggers neurotransmission?

Arrival of an action potential at the end of the axon.

What are neurotransmitters?

Chemicals that transmit information between neurons; can be excitatory or inhibitory.

What do excitatory neurotransmitters do?

Increase the likelihood of an action potential.

What do inhibitory neurotransmitters do?

Decrease the likelihood of an action potential.

What are the components of the hindbrain?

Medulla, Pons, Cerebellum.

What does the medulla regulate?

Breathing, heart rate, and blood pressure.

What functions does the pons serve?

Similar to the medulla and also body movement.

What is the cerebellum responsible for?

Body movement, balance, coordination, fine-tuning motor skills, and learning.

What does the midbrain regulate?

Eye muscles; processes auditory and visual information; initiates voluntary movement.

What is the forebrain?

The largest part of the brain containing structures for cognitive functioning, motor movement, regulation of temperature, eating, sleeping, and more.

What structures comprise the limbic system?

Hypothalamus, amygdala, hippocampus, and cingulate cortex.

What is the thalamus?

The sensory relay station; receives information from senses (except smell) and relays to the cortex.

What is the hypothalamus responsible for?

Regulation of drives and motivations (hunger, thirst, temperature, sexual behavior).

What is the hippocampus' role?

Learning and memory.

What is the amygdala's role?

Determines the emotional significance of stimuli, especially fear.

What is the function of the cingulate gyrus?

Attention and cognitive control.

What is the basal ganglia involved in?

Voluntary motor control.

What is the cerebrum?

The upper part of the brain with two hemispheres; contains four lobes; the cerebral cortex is the thin outer layer.

What are the functions of the frontal lobes?

Planning, impulse control, attention, abstract thinking; include the primary motor cortex.

What are the functions of the parietal lobes?

Sensation and perception of touch; contains the somatosensory cortex.

What is the corpus callosum?

Connects the two hemispheres and enables extensive communication for logical and creative tasks.

What are the temporal lobes responsible for?

Hearing; contains the auditory cortex.

What are Broca's and Wernicke's areas?

Broca's area produces speech; Wernicke's area understands language.

What is the occipital lobe responsible for?

Vision; contains the primary visual cortex.

What is the cerebral cortex?

The thin outer layer of the cerebrum.

What is neuroplasticity?

The brain’s ability to adopt new functions, reorganize itself, or form new neural connections.

What is neurogenesis?

Development of new neurons.

What is EEG used for?

Measuring electrical activity of the brain via scalp electrodes.

What is MRI used for?

Producing detailed images of brain structure using magnetic fields.

What is fMRI used for?

Measuring brain activity indirectly by detecting changes in blood oxygenation.

What is PET used for?

Measuring blood flow to active brain areas.