1. KEY CONCEPT Fungi recycle nutrients in the environment.

2. Fungi may be decomposers, pathogens, or mutualists.
Fungi and bacteria are the main decomposers in any ecosystem.
decompose dead leaves, twigs, logs, and animals
return nutrients to the soil
Called saprobes (they eat dead stuff)

3. Fungi can act as pathogens.
Some always cause disease
Others cause disease when a change in homeostasis
gives fungi a chance to grow.
Corn smut

4. Fungi can act as pathogens.
human diseases include ringworm and athlete’s foot
Extra moisture
Sometimes overuse or incorrect use of antibiotics cause fungal infections
Yeast infections

5. ringworm
Athlete’s foot

6. Fungi can act as pathogens.
May damage fruit trees and wooden structures
Plant diseases include Dutch elm disease
Rusts
Smuts
Blights
Elm bark beetles burrow into Dutch Elm trees and spread the fungus

7. Ergot Fungus on wheat
Causes hallucinations and erratic behavior
May have been the cause during the Salem Witch Trials, Salem, Mass. 1692

8. Fungi can act as mutualists.
Mutualism: a relationship between 2 organisms where both benefit.
lichens form between fungi and algae
Fungi are the home
Algae (or cyanobacteria)
make the food

9. Fungi can act as mutualists.
mycorrhizae form between fungi and plants
Plants provide the home and food
Fungi help the plants take up water and nutrients

10. Fungi can act as mutualists.
relationships form between fungi and some insects

11. Fungi are studied for many purposes.
Fungi are useful in several ways.
as food
as antibiotics
as model systems for molecular biology