Multiple choice

How do organisms generate energy when oxygen is not available?

  1. cellular respiration

  2. fermentation

  3. lactation

  4. photosynthesis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the absence of oxygen, organisms use fermentation to regenerate the electron carriers needed to keep glycolysis running. This allows them to continue generating a small amount of ATP without aerobic cellular respiration.

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