Passage:
In 1867, Swiss botanist Simon Schwendener proposed the dual hypothesis of lichens, asserting that lichens were not autonomous plants but rather composite organisms consisting of a green alga trapped within a parasitic fungus. Initially met with fierce resistance from traditional lichenologists who viewed the fungal component as a structural tissue of a single plant, Schwendener’s framework gained gradual support as microscopic staining techniques improved. In 1879, German mycologist Heinrich Anton de Bary expanded Schwendener’s concept by coining the term 'symbiosis' to describe the living together of unlike organisms. Crucially, de Bary departed from Schwendener’s strictly antagonistic model of fungal parasitism; instead, de Bary posited a broad spectrum of symbiotic associations, ranging from mutually beneficial mutualism to destructive parasitism. De Bary demonstrated that while certain fungal hyphae absorb nutrients directly from algal cells without causing immediate host death, the algal partner retains photosynthetic capabilities that nourish the fungal matrix.
Which of the following statements regarding nineteenth-century theories of lichen biology is explicitly supported by the passage? Select all that apply.
- Traditional lichenologists initially rejected Schwendener's dual hypothesis because they considered the fungal element to be structural tissue belonging to an individual plant.Cevap
- BDe Bary's definition of symbiosis restricted the relationship between unlike organisms exclusively to mutually beneficial interactions.
- In de Bary's model, algal cells involved in lichen associations maintain their ability to perform photosynthesis.Cevap