Which organism is able to produce organic matter from inorganic sources using light or chemical energy?

• A. Tombolo
• B. Well-Mixed Estuary
• C. Bathyal Zone
• D. Autotroph

Answer: (D)

Organisms that can synthesize organic matter from inorganic carbon using energy from light or chemical reactions are autotrophs. They form the producers in an ecosystem by converting inorganic carbon (like CO2) into organic compounds such as glucose. Photoautotrophs use light energy to drive photosynthesis (think plants, algae, and cyanobacteria), while chemoautotrophs rely on chemical energy from inorganic reactions (for example, bacteria near hydrothermal vents using hydrogen sulfide).

That makes autotroph the correct description for the organism in question because it captures the ability to produce organic matter from inorganic sources using either light or chemical energy. The other options are not organisms and don’t describe this metabolic capability.