Explain THREE unique characteristics of fungi. Solution Three unique characteristics of fungi are- 1)Fungi are filamentous and not truly multicellular. They are composed of unique thread-like filamentous structures called hyphae. In higher fungi, these hyphae anastomose to form a network called mycelium.The cell wall of fungi is composed of chitin or cellulose. Fungi can build mutual relationships with other organisms in order to get nutritional benefits from such association. For example: The symbiotic relationship between funfi and algae is called lichen. 2) They need preformed food, optimum temperature, pH and moisture to grow properly. In order to avoid dessication, they also require some amount of water to grow. They are resistant to osmotic pressure and hence, can grow in relatively high salt and sugar concentrations. 3)Fungi are heterotrophic and they lack plastids.They collect nutrients from the environment, from dead or living organisms. Fungi are capable of metabolising complex carbohydrates (like lignin)..