Pesticides in the soil are eventually broken down by which organisms?

• A. Plants
• B. Bacteria and fungi
• C. Insects
• D. Algae

Answer: (B)

Microorganisms in the soil are the main agents that break down pesticides over time. Bacteria and fungi have a wide range of enzymes that can attack and metabolize many pesticide chemistries, transforming them into less toxic compounds and eventually mineralizing them to simple substances like carbon dioxide and water. Their diverse metabolisms let them degrade a broad spectrum of pesticides under different soil conditions, making them the primary drivers of soil pesticide degradation. Plants may take up and modify some pesticides, but actual breakdown in the soil is dominated by microbes. Insects and algae aren’t the primary degraders in this context. So the organisms responsible are bacteria and fungi.