Science — AI-generated practice question

Anaerobic respiration is the breakdown of glucose in the absence of oxygen to release energy. It produces less energy compared to aerobic respiration. For example, in yeast, glucose is broken down to produce ethanol and carbon dioxide. In our muscles during heavy exercise, glucose breaks down to produce lactic acid, causing muscle cramps.

Source: Life Processes, Chapter 5

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• The examiner expects: definition (no oxygen), products (ethanol + CO₂ in yeast / lactic acid in muscles), and the fact that less energy is released.
• Mentioning both examples (yeast and human muscles) secures both marks.
• Do not confuse anaerobic with aerobic — aerobic uses oxygen and releases CO₂ + water + more energy.