During a laboratory examination of a bread mould (*Rhizopus stolonifer*) culture, root-like hyphal structures called rhizoids are observed penetrating the substrate. What is the primary functional role of these rhizoids?
- Anchoring the mycelium to the substrate and secreting extracellular enzymes for digestionAnswer
- BIngesting solid bread particles holozoically through specialized cell mouth pores
- CSynthesizing organic nutrients autotrophically using absorbed sunlight and water
- DElevating sporangia into the air to facilitate the dissemination of asexual spores
Answer
The primary role of rhizoids in Rhizopus stolonifer is to anchor the fungus into the organic substrate and secrete extracellular enzymes to digest complex nutrients into soluble forms for absorption.
Rhizoids are specialized root-like hyphae in moulds such as Rhizopus that penetrate the substrate. They perform a dual role: securely anchoring the fungal mycelium to the food source and secreting extracellular digestive enzymes (e.g., amylases) to hydrolyze insoluble substrate materials into simple soluble compounds, which are then absorbed across the chitinous cell wall.
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Key Concept
Rhizoid function and saprophytic extracellular digestion in filamentous fungi