Question

question 5
dopamine ______.
a is an addictive drug
b is not normally produced by healthy humans
c is normally only produced at night
d triggers a fight or flight reaction in most humans
e is a neurotransmitter

question 6
drugs of abuse ______.
a stimulate pain sensors
b block motor neurons
c deactivate the neurons in the brain
d stimulate dopamine production
e stimulate melatonin production

Explanation:

Question 5

• Option A: Dopamine is a neurotransmitter, not an addictive drug (drugs may mimic or affect its function).
• Option B: Healthy humans normally produce dopamine (it's involved in many brain functions).
• Option C: Dopamine production isn't limited to night; it's produced as needed.
• Option D: Fight - or - flight is triggered by adrenaline, not dopamine.
• Option E: Dopamine is a neurotransmitter that plays roles in reward, motivation, etc.

• Option A: Drugs of abuse don't primarily stimulate pain sensors.
• Option B: They don't block motor neurons as a main effect.
• Option C: They don't deactivate brain neurons; often they over - activate reward - related pathways.
• Option D: Many drugs of abuse (like cocaine, opioids) stimulate dopamine production or enhance its effects in the reward pathway, leading to addictive behavior.
• Option E: Drugs of abuse don't stimulate melatonin production (melatonin is for sleep - wake cycles).

Answer:

E. is a neurotransmitter

Question 6