Chitin walls
Unlike cellulose in plants or peptidoglycan in bacteria. Chitin also appears in arthropod shells — a hint of shared history with animals.
Fungi are neither plants nor animals, though molecular trees place them closer to animals. They digest outside the cell and absorb the soup — osmotrophy — behind a chitin-rich wall.
The familiar mushroom is a fruiting body. Most of the organism is mycelium in soil, wood, leaf litter or a living partner.
Traits
Osmotrophy
Enzymes go out; sugars and peptides come in. A fungus is a digestive tract turned inside out.
Hyphae and yeasts
Filaments explore space; yeasts are single cells that bud. Candida can switch forms — dimorphism — in some settings.
Closer to animals
Opisthokonts share a flagellated ancestor story. Fungi are not 'failed plants'.
Spores
Meiotic and mitotic spores travel on air and animals. A single puffball can release billions of particles.
Partnership default
Mycorrhizae link most land plants to phosphorus. Lichens are fungi farming phototrophs.
Once you see fungi as a kingdom, 'mould on bread' becomes one lifestyle among yeasts, mycorrhizae and human pathogens.
Keep exploring
More in Tree of microbes
Bacteria
Single-celled prokaryotes with cell walls ? the oldest widespread life form, and both partners and pathogens.
Familiarity 95Viruses
Packets of DNA or RNA that are not cells — they replicate only inside living hosts.
Familiarity 96Archaea
A prokaryotic domain that is not bacteria — methanogens, extremophiles and no known human pathogens.
Familiarity 35Bacteriophages
Viruses that infect bacteria — Earth's most abundant biological entities, and a concept-level idea in medicine.
Familiarity 42Protozoa
Motile unicellular eukaryotes — a teaching grade that includes pond ciliates and a minority of serious parasites.
Familiarity 58