1. Multiple Choice: Which neurotransmitter is most commonly associated with the reward pathway and substance addiction? a) Serotonin b) Dopamine c) GABA d) Acetylcholine Correct Answer: b) Dopamine Rationale: Dopamine is the neurotransmitter most commonly linked to the pleasure and reward pathways in the brain, which are significantly affected during substance abuse and addiction. 2. True/False: Physical dependence on a substance is characterized by the presence of withdrawal symptoms when the substance is not taken. Answer: True Rationale: Physical dependence is indicated by withdrawal symptoms that occur when the substance use is reduced or stopped, reflecting the body's adaptation to the substance. 3. Fill-in-the-Blank: The term "_________" refers to the compulsive seeking and taking of a substance despite adverse consequences. Correct Answer: Addiction Rationale: Addiction is defined by compulsive drug-seeking