Which organism is associated with slow nutrient cycling?

• A. Bacteria
• B. Fungi
• C. Algae
• D. Protozoa

Answer: (B)

The main idea here is how different soil organisms affect how fast nutrients are released back to plants. Fungi tend to slow nutrient cycling because they are specialized at decomposing complex plant polymers like lignin and cellulose. Their extensive hyphal networks let them explore soil and access tough litter, but the mineralization of that material happens more gradually. They also often immobilize nutrients in their own biomass and have high carbon-use efficiency, so a larger portion of the carbon they take up stays in fungal tissue rather than being rapidly converted into plant-available nutrients. This combination—slow breakdown of complex organic matter and nutrient retention—leads to slower overall nutrient turnover in fungal-dominated systems. In contrast, bacteria rapidly mineralize simple substrates, and protozoa can speed up nutrient release by grazing on bacteria, while algae mainly contribute to surface processes and primary production rather than slow decomposition. So fungi are the best match for slow nutrient cycling.