Plant–fungus symbiosis — naming the association with roots A very common mutualistic, symbiotic relationship between a fungus and the roots of a plant is called what?
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ALichen
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BMycorrhiza (mycorrhizal association)
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CAscomycete
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DBasidiomycete
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ERhizobium
Answer
Correct Answer: Mycorrhiza (mycorrhizal association)
Explanation
Introduction / Context:Plants and fungi often form mutualisms that improve nutrient and water acquisition. The best-known root–fungus partnership has a specific name that appears across ecology, botany, and agriculture curricula.
Given Data / Assumptions:
- Symbiosis is between plant roots and a fungus.
- Mutual benefits include enhanced nutrient uptake and carbon supply to the fungus.
- We must identify the standard term for this association.
Concept / Approach:
Mycorrhizae are associations in which fungal hyphae colonize root cortex tissues or soil around roots (ectomycorrhizae and endomycorrhizae). The plant gains improved uptake of phosphorus, nitrogen, and micronutrients; the fungus receives photosynthate. This boosts plant fitness, particularly in nutrient-poor soils.
Step-by-Step Solution:
Identify the partners: plant roots + fungi.Recall the technical term for this mutualism: mycorrhiza.Verify that lichen is algae/cyanobacteria + fungi, not roots.Choose “Mycorrhiza (mycorrhizal association)”.Verification / Alternative check:
Ecology and plant physiology texts define mycorrhizae as the primary plant–fungus mutualism at roots, distinct from lichen.
Why Other Options Are Wrong:
Lichen involves a photosynthetic partner and fungi, not plant roots. “Ascomycete” and “Basidiomycete” are fungal phyla, not relationships. “Rhizobium” is a nitrogen-fixing bacterium associated with legumes, not a fungus.
Common Pitfalls:
Confusing mycorrhiza with lichen or with bacterial nodulation. Always match the partners in the definition.
Final Answer:
Mycorrhiza (mycorrhizal association)