Chemosynthetic organisms at hydrothermal vents

Steps:

• Recognize the dark, lightless environment rules out photosynthesis for glucose synthesis.
• Note energy source is chemicals from hot volcanic water, indicating chemosynthesis.
• Recall chemosynthesis uses inorganic chemicals (e.g., H2S) to produce organic compounds like glucose via CO2 fixation.
• Match to option C, which describes chemosynthetic autotrophs.

Why C is correct:

• Chemosynthesis definition: Autotrophic process using chemical energy (not light) to convert CO2 and H2O into glucose, as in 6CO2 + 6H2O + energy → C6H12O6 + 6O2, powered by vent chemicals.

Why the others are wrong:

• A: These thermophiles have heat-stable enzymes adapted to high temperatures, not easily denatured.
• B: Chemosynthesizers require CO2 as a carbon source for glucose production.
• D: They are autotrophs making their own food from chemicals, not carnivores relying on prey.

Final answer: C