Science (086) — AI-generated practice question

Decomposers (bacteria, fungi) break down dead organic matter and waste into simpler substances, returning nutrients to the soil. In nature, they recycle all biodegradable waste automatically, preventing its accumulation.

The problem arises because many human-made materials — plastics, synthetic chemicals — are non-biodegradable. Decomposers cannot act on them since specific enzymes needed to break these substances down are absent in microorganisms. These materials persist in the environment for very long periods and may harm ecosystem members.

Therefore, human waste-disposal systems (recycling, landfills, sewage treatment) must intervene to manage what decomposers cannot, compensating for this biological limitation.

Source: Chapter 13, Section 13.2.2 — Managing the Garbage we Produce

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• The question has two linked parts: (1) what decomposers do, and (2) why human systems must compensate. Address both clearly.
• Key concept: biodegradable waste is handled by decomposers naturally; non-biodegradable waste is not, because the right enzymes don't exist in bacteria/saprophytes.
• Examiners expect the terms biodegradable, non-biodegradable, and the enzyme-specificity logic from the chapter.
• Don't over-explain decomposers from outside the textbook — stay grounded in the passage.