Though fungi share many traits with plants, there are several key differences between plants and fungi that require fungi to be classified into their own kingdom. Fungi are unable to produce their own food through photosynthesis.
The cell walls of fungi organisms are made of a substance called chitin. Chitin adds rigidity to the cell wall of fungi in the same way that cellulose provides strength to the cell walls in plants.
Multicellular or Unicellular
Fungi can be either one cell or multiple cells.
Eukaryote
The cells in fungi are complex. Cells of eukaryotic organisms have organelles and a nucleus to contain genetic information.
Heterotroph
As decomposers, fungi break down other organisms as food into raw nutrients.
