Question

a loss of plant life on the planet would block aerobic respiration in humans because of the loss of ______.

• glucose.
• sunlight.
• carbon dioxide.
• glucose and oxygen
• oxygen.

Explanation:

Aerobic respiration in humans requires oxygen ($O_2$) as the final electron acceptor. Plants produce oxygen via photosynthesis. Loss of plant life would reduce oxygen availability, blocking aerobic respiration. Glucose for respiration can come from other sources (e.g., food), so only oxygen loss directly blocks the process.

Answer:

E. oxygen.