MDCAT Biology MCQ #300

Certain sulfur bacteria utilize hydrogen sulfide instead of water during photosynthesis. What substance is released as a byproduct instead of oxygen?

MDCAT Biology MCQ #300

  1. Question 1

    Q1. Certain sulfur bacteria utilize hydrogen sulfide instead of water during photosynthesis. What substance is released as a byproduct instead of oxygen?

    • A) Carbon dioxide
    • B) Elemental sulfur
    • C) Methane
    • D) Sulfuric acid

    Answer: Elemental sulfur

    Explanation: Sulfur bacteria use hydrogen sulfide as a reductant, releasing sulfur instead of oxygen. Oxygen is the byproduct in oxygenic photosynthesis.