According to the material, what is the functional unit of life?

• A. Molecules and Atoms
• B. Protons
• C. An Ion
• D. Organelle

Answer: (D)

Life’s essential activities are carried out by specialized structures inside cells. Organelles are the functional units because each one performs a specific, vital task that supports the cell’s life—energy production in mitochondria, protein synthesis in ribosomes, waste processing in lysosomes, and so on. These compartments create the organized, regulated environment needed for metabolism and growth. In contrast, atoms and molecules are just raw building blocks, and protons or ions are merely particles without the capacity to coordinate the complex, integrated processes that keep a cell alive. So, within this framework, the organelle is the functional unit of life because it serves as the working module that enables cellular life.