Dopamine is a chemical released by neurons to send signals to other nerve cells. the brain includes several distinct dopamine pathways, one of which plays a major role in reward motivated behavior.
smoking is a habit, in a habit there is the cue, routine, and reward. with smoking the cue can be different things, most commonly stress or anxiety. the routine how you react to those cues, the reward is the chemical 'triggers' that are pulled inside you're brain leaving you feeling calm, happy, or relieved, etc.
Hello, Heredity is located in genes, found in the chromosomes of each cell.
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The correct answer is (d.) proteins. Higher organisms use nitrogen to make their protein. Food that is containing protein also involves nitrogen in it. Protein also has amino acids that contain nitrogen in it which is a necessary essential nutrient for the body.