What Are Fungi?
§ Fungi are eukaryotic heterotrophs that have cell walls.
complex carbohydrate, makes up their cell walls
§ Digest their food outside their bodies and then absorb it
§ Feed on decaying matter in the soil
§ Live as parasites, absorbing nutrients from their host
Structure and Function of Fungi
§ All fungi are multicellular except yeasts.
§ Composed o f thin fi laments called hyphae
§ Cross walls divide some fungi into cells containing one or two nuclei
§ Cross walls are tiny openings through which the cytoplasm and nuclei can move
a tangled mass of hyphae
§ Mycelium absorb food due to its large surface area coming into contact with a
§ Fruitinq body is a reproductive structure
growing from the mycelium in the Sofl beneath it.
§ Clusters of mushrooms are often part of the same mycelium hence, the same organism.
§ A "fairy ring" is composed of the fruiting bodies of
mushrooms that developed at the outer edges of a single mycelium.
§ As the center nutrients become depleted, new mushrooms sprout only at the edges
of the mycelium producing a ring.
Reproduction in Fungi
§ Most fungi reproduce sexually and asexually.
§ Cells or hyphae break off from a fungus and begin to grow on their own.
§ Some produce spores which scatter and produce new organisms (a spore is a reproductive
§ Spores are produced in sporangia
§ Sporangia are found at the tips of specialized hyphae called sporangiophores
§ Involves two different mating types
§ Not male and female but "+" (plus) and
§ When opposite mating types meet, they fuse, bringing plus and minus together in
the same cell.
§ Form a diploid zygote nucleus, which enter meiosis producing haploid spores.
How Fungi Spread
§ Fungal spores are found in almost every environment.
§ Mold will appear where there is the right combination of moisture and food
§ A few liters of fresh air may contain hundreds of spores from many species of
§ Spores will grow if they have the right temperature, moisture and food
§ Some fungi are specialized to lure animals, which disperse fungal spores over
a long distance.
§ Stinkhorns smell like rotting meat and attract flies
§ The spore-containing fluid in ingested by the flies that distribute it over many