______ are a symbiosis between a photosynthetic organism and a fungus.
Part 1 | Part 2 | Part 3 | Part 4 | Part 5. Biology : Symbiotic Fungal Associations: Lichens and Mycorrhizae : Part Five. Symbiotic Fungal Associations: Lichens and Mycorrhizae. Lichens are a symbiosis between a photosynthetic organism (an alga or cyanobacterium) and a fungus (either an ascomycete or a basidiomycete). Lichen often live in marginal environments and often grow only one or two centimeters per year.