Biological Basis of Behavior Flashcards

Which part of the neuron integrates incoming signals and initiates the action potential?

Answer: Axon hillock

The axon hillock sums excitatory and inhibitory postsynaptic potentials and fires an action potential when the threshold is reached.

Heritability estimates in behavioral genetics reflect:

Answer: The proportion of population variance in a trait attributable to genetic differences

Heritability is a population statistic indicating what proportion of trait variability in a specific population is due to genetic variation.

The reticular activating system (RAS) in the brainstem plays a key role in regulating:

Answer: Arousal and states of consciousness

The RAS modulates arousal, wakefulness, and attention by sending diffuse activating signals to the cortex.

Which hormones are released by the adrenal medulla during acute stress?

Answer: Epinephrine and norepinephrine

The adrenal medulla releases epinephrine (adrenaline) and norepinephrine in response to acute stress via sympathetic nervous system activation.

In the context of genetics, a phenotype that appears only when two copies of a recessive allele are present is called:

Answer: Autosomal recessive

Autosomal recessive traits require homozygous recessive genotype (two copies of the recessive allele) to be expressed phenotypically.

The cerebellum is primarily responsible for:

Answer: Coordinating movement, balance, and fine motor skills

The cerebellum fine-tunes motor movements, maintains balance, and is essential for motor learning and coordination.

When a neurotransmitter binds to an inhibitory postsynaptic receptor, the most common result is:

Answer: Hyperpolarization making the cell less likely to fire

Inhibitory receptors typically open chloride channels or potassium channels, hyperpolarizing the membrane and reducing the probability of an action potential.