The Fungi are a group of eukaryotic, non-phototrophic organisms with rigid cell walls. This includes mushrooms, molds and yeasts. Many fungi are saprophytes, getting nutrients by absorbing them from dead, decaying plant material.Still, other fungi are parasitic, stealing resources from a host organism.et's review. The Fungi are a group of eukaryotic, non-phototrophic organisms with rigid cell walls. This includes mushrooms, molds and yeasts. Many fungi are saprophytes, getting nutrients by absorbing them from dead, decaying plant material. Still, other fungi are parasitic, stealing resources from a host organism.