Molds    yeasts, and higher fungus are examples of fungi. All fungi are eukaryotic and their cell membranes include sterols but not peptidoglycan. Cellulose makes up their cell walls; it is the same material that plants employ as a building material. The majority of fungi are aerobic chemoheterotrophs that need organic nourishment. Many fungi are also saprophytes, which feed by absorbing dead organic matter from the soil and water. Fungal stains are still a crucial diagnostic tool for identifying infectious microorganisms in the histology laboratory. After growth in culture, fungi are identified based on visual characteristics such as colony morphology and color.