Cell wall is composed of chitin , a polymer that consists of subunits of a nitrogen-containing sugar.
Chitin is highly resistant to enzymatic breakdown.
Fungi lack chlorophyll and are nonphotosynthetic. Nonetheless, some species exist as symbiotic partners with algae in lichens. Most fungi have a filamentous body plan, in which filaments called hyphae permeate through the habitat in which they live. The entire tangled mass of hyphae is called a mycelium . The biomass of a mycelium can be quite extensive.