Answer: The extraradical hyphae vastly increase the absorptive surface area beyond the root hair zone.
- A Mycorrhizal fungi produce phosphatase enzymes mainly, with little other contribution
- B The extraradical hyphae vastly increase the absorptive surface area beyond the root hair zone
- C Mycorrhizal fungi convert organic phosphorus to plant-available forms mainly, rarely otherwise
- D Glomus secretes phosphorus-mobilizing acids mainly in alkaline soils, rarely in acidic ones
Correct answer: B. The extraradical hyphae vastly increase the absorptive surface area beyond the root hair zone
Explanation: The extensive network of extraradical hyphae of Glomus mycorrhizae extends far beyond the nutrient depletion zone around roots, massively increasing the surface area for phosphorus uptake from soil.
Sewage passes through physical removal (primary), then aerobic biological treatment where microbes form flocs that consume organic matter (secondary); the settled activated sludge is then digested anaerobically to produce biogas - a deliberate switch from aerobic to anaerobic conditions between stages.
Concept context
Microorganisms in food, medicine, sewage treatment, biocontrol, and biofertilizers