Which process uses chemical energy to synthesize organic matter, typical in hydrothermal vent ecosystems?

• A. Chlorophyll
• B. Chemosynthesis
• C. Convergent Evolution
• D. Denitrifying Bacteria

Answer: (B)

Chemosynthesis is the method by which microbes use energy from chemical reactions, such as the oxidation of reduced inorganic molecules like hydrogen sulfide, to fix carbon dioxide into organic matter. In hydrothermal vent ecosystems, sunlight cannot reach the deep ocean, so primary production relies on these chemical energy sources rather than light. The vent microbes convert inorganic compounds from vent fluids into organic biomass, supporting the rest of the vent community. Chlorophyll is linked to photosynthesis and requires light, which is not available here. Denitrifying bacteria are involved in nitrogen cycling, not in generating organic matter for the food web. Convergent evolution is an evolutionary pattern, not a metabolic process.