Biology - Fungi
* are _opportunistic_ - they do not normally cause disease, but do so in
hosts which are weakened in some way; for example, thrush (Candida)
* are _systemic_ - they occur deep in the systems or tissues of the body;
usually they have entered as spores via the lungs; not contagious
* are _cutaneous_ and _sub-cutaneous_ - they live on the surface and
below the surface of the skin; obtain nutrients from skin or hair; for
example, ringworm, athlete's foot, jock itch
In plants, fungal diseases are usually specific to one part of a plant.
They can be classified in a number of ways, including according to their
method of nutrition.
_Heterotrophic _ fungi obtain nutrients from the living cells of the
_Saprophytic_ fungi feed on dead tissues. Some secrete enzymes that kill
the host cells, and they then feed on the dead cells.
Fine fungal hyphae or threads penetrate the surface to access the cells
below, and the powdery layer on the surface may contain the reproductive
spores. Common plant diseases caused by fungi include: potato blight, mould
rot of fruits, powdery mildew, rust of wheat and other cereals, Dutch elm
disease, and dieback of eucalypts by cinnamon fungus.
Mould feeding on bean tissue
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