Step 1: Heroin is an opioid drug synthesized from morphine, which is derived from the opium poppy. Morphine is the precursor to heroin.
Step 2: Heroin is chemically diacetylmorphine, meaning that it is morphine with two acetyl groups added to the molecule.
Step 3: Therefore, heroin is a derivative of morphine, not cocaine, caffeine, or nicotine.