Practice free →
HomeICAR JRFPlant SciencesSoil and Plant Nutrition › How do fungal hyphae help a root overcome a nutr…

How do fungal hyphae help a root overcome a nutrient depletion zone?

AThey dissolve the soil minerals with strong acid
BThey pump water upward into the root cortex
CThey are narrow and spread beyond that zone
DThey store nitrogen fixed from the atmosphere
Answer & Solution
Correct answer: C. They are narrow and spread beyond that zone
1. A nutrient depletion zone develops around a root when uptake is rapid, concentrations are low, diffusion is slow or moisture is low. 2. These conditions are very common, so most plants rely on fungi to help take up minerals. 3. Mycorrhizae increase the surface area of the root system because their hyphae are narrow and spread beyond the depletion zone. 4. Hyphae can also grow into small soil pores and reach phosphorus that would otherwise be unavailable. 5. Nitrogen fixation belongs to rhizobia in nodules, so storing fixed nitrogen is the wrong partnership. 6. The benefit of the association is best observed in poor soils, where reaching beyond the depleted shell matters most. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 31 "Soil and Plant Nutrition", section 31.3 Nutritional Adaptations of Plants_
Solve this in the app — ICAR JRF practice & 24k+ MCQs →
Related questions