Kingdom Fungi: Types of Fungi and Their Characteristics
I. Background Information and Characteristics
A. Background Information
1. Fungi (singular: fungus) are organisms that do not contain chlorophyll—they rely on other organisms
for energy (they are heterotrophs).
a. parasitic fungi— feed on living organisms by breaking down their tissues with enzymes.
1. Examples: athlete’s foot; “ick” on aquarium fish; fungus that causes Dutch elm disease; ringworm
b. saprophytic fungi— use enzymes to break down and feed on dead organisms.
1. These fungi are decomposers— are important because they:
a. return (recycle) nutrients to the soil to be used by the plants.
b. help clear the Earth of dead organic material.
2. Fungi usually live in moist (or humid), shady (or dark) areas.
3. Some types of fungi are helpful to us:
a. used as food or in food production— ex. mushrooms, truffles, yeast to make bread rise
b. used to make certain drugs— ex. penicillin.
4. Some fungi are harmful or damaging:
a. spoil food—ex. mold
b. cause disease in plants and animals—ex. fungus that caused the potato blight in Ireland in the 1840’s.
c. mildew can destroy leather goods, fabrics, and plastics
B. Characteristics and Structure
1. The body of a fungus is made up of threadlike structures or filaments called hyphae.
a. Hyphae grow into the fungus’s food source and produce digestive enzymes which breakdown the
food.
1. The broken-down food passes into the fungus by diffusing through the hyphae (the enzymes digest
the food so the particles are small enough to pass through the hyphae’s pores).
2. Hyphae also absorb water (by osmosis) for the fungus.
2. Most of a fungus’s hyphae are down in the food source— the part we see is usually only a small part of
the whole organism.
a. For example, we may see just a few mushrooms on our lawn, but the whole fungus may 35 meters
across.
3. The body of a fungus is made up of 2 parts:
a. mycelium = a mass of twisted, interconnected hyphae that form the main body of the fungus which
usually not seen because it is down inside the food source.
b. fruiting body = the part of the fungus that is responsible for reproduction by producing spores; it is
the part of the fungus that we see .
4. Most fungi reproduce by producing spores in their fruiting bodies.
a. spores = small reproductive cells that form into a new organism without the need of fertilization.
b. When the spores are mature, they are released into the air by the fruiting body.
1. If the spore lands in an area with a food source and enough moisture, it will develop into a new
fungus of the same kind.
5. Fungi are classified according to the type of fruiting body they have.
II. Types of Fungi
A. Zygote or Sporangium Fungi—Phylum Zygomycota
1. This type of fungus produces spores in round spore cases called sporangia.
a. The sporangia form on the top of long, tall hyphae that stick up from the surface of the fungus.
b. The sporangia turn dark when the spores are mature and split open to release them.
2. Molds that form on bread, fruits, and other foods are examples of this type of fungus.
a. Bread that you buy in a grocery store usually has preservatives in it that slow down the development
of spores into the fungus.
b. Bakery bread usually does not contain such preservatives and may become moldy much faster.
B. Sac Fungi—Phylum Ascomycota
1. This type of fungus produce spores in little sacs called asci (singular: ascus).
a. The ascus breaks open when the spores are mature.
2. Examples of this fungus are truffles, mildew, and yeasts.
a. In addition to forming spores, yeast can reproduce by budding.
1. budding = a form of asexual reproduction in which a new organism grows off the side of the
parent.
b. Yeasts metabolize their food by fermentation, producing alcohol and carbon dioxide as wastes.
C. Club Fungi—Phylum Basidiomycota
1. This type of fungus produces spores in club-shaped structures called basidia (singular: basidium).
a. On a mushroom, the basidia are on the gills found on the underside of the cap.
1. When mature, the spores are pulled down out of the cap by gravity.
2. Examples of this type of fungus are mushrooms, puffballs, bracket fungi.
a. Puffballs dry out when the spores inside it are mature. They are releases when an animal touches
them or when raindrops fall on them.
b. Bracket (or shelf) fungi are the shelf-like fungus that are found growing on the side of trees or on
dead logs.
III. Lichen: A Special Kind of Relationship
A. Lichen are made up of a fungus and either a cyanobacterium or a green algae living together.
1. The algae (or cyanobacteria) live within the tangle of hyphae that make up the fungus.
2. By living together and helping each other, lichen can live in environments that neither could live in
alone (ex. on rocks, in deserts, on wooden poles, even in the ice and snow in the Arctic).
a. The fungus part provides the algae with water and minerals that the fungus absorbs from whatever the
lichen is growing on.
b. The algae part uses the water to do photosynthesis to make food for the fungus and itself.
3. symbiosis = a type of relationship in which 2 different organisms live together and benefit from (help)
each other (also called mutualism).
B. Lichen are an example of organisms called pioneer species.
1. Pioneer species are the first organisms that go into rocky areas or areas that have had lava deposited by
volcanic activity.
a. Lichen release acids that break down the rock and cause it to crack. Bits of dead lichen and the rock
particles combine to produce the first soil in these barren areas.
1. As seeds land in this new soil, plants begin to grow.
2. Lichen do not do well in areas where there is a high amount of air pollution.
a. Scientists use lichen to monitor air pollution levels.
1. If they disappear from an area, levels are increasing.
2. If they return to an area, then the methods used to clean up the pollution have been successful and
levels are decreasing.