1. Kingdom Fungi
Chapter 22

2. Characteristics of Fungi
All fungi share 3 characteristics:
Fungi have threadlike bodies
Fungal cell walls contain chitin
CHITIN – a tough carbohydrate that is found in the hard outer covering of insects and other organisms
Fungi are heterotrophic

3. Body Structure
Fungi have bodies made of threadlike strands called HYPHAE.
Hyphae form a tangled mass often many meters long called a MYCELIUM.
In some fungi, hyphae also form root-like structures called RHIZOIDS

4. Obtaining Nutrients
Fungi release enzymes that break down organic and inorganic matter into nutrients.
Fungi absorb the nutrients across their cell walls.
SAPROBES – fungi that absorb nutrients from dead organisms
PARASITES – fungi that absorb nutrients from living hosts

5. Reproduction Most fungi reproduce sexually and asexually
In SEXUAL reproduction, spores are produced by meiosis
Allows for genetic diversity
Specialized structures (like mushrooms) for sexual reproduction
In ASEXUAL reproduction, spores are produced by mitosis
Allows for rapid reproduction
Fungi that do not have an observed sexual stage are grouped together and called IMPERFECT FUNGI

6. Reproduction

7. Yeast and Mold
The words “yeast” and “mold” refer to SPECIFIC STAGES of the life cycle that are shared by several types of fungi
YEAST
Common name for fungi that exist in a unicellular stage
Reproduce asexually by budding
MOLD
The rapidly growing, asexually reproducing stage of some types of fungi

8. Groups of Fungi Chytrids (Family CHTRIDIOMYCOTA)
A group of aquatic fungi that provide clues about the evolution of fungi
Mostly unicellular saprobes that feed on protists, plants, animals, and other fungi
Common parasites of aquarium fish
Believed to have been the cause of the decline in amphibians in the wild

9. Groups of Fungi (cont.) Zygote Fungi (Family ZYGOMYCOTA)
Named for sexual reproductive structures that produce zygotes inside a tough capsule (called a ZYGOSPORANGIUM)
Asexual reproduction by spores is most common in zygote fungi
Example: RHIZOPUS – bread mold; can also live in soil

10. Groups of Fungi (cont.) Sac Fungi (Family ASCOMYCOTA)
ASCUS – a sac-like reproductive structure that produces spores
Usually reproduce asexually
Asexual spores called CONIDIA form by mitosis on specialized hyphae called CONIDOPHORES

11. Groups of Fungi (cont.) Club Fungi (Family BASIDIOMYCOTA)
Include mushrooms, toadstools, puffballs, jelly fungi, shelf fungi, rusts, and smuts
BASIDIUM – a club-like sexual reproductive structure that produces spores
Sexual reproduction is most common – usually form rings
Basidiocarp – reproductive structure (the “actual” mushroom)

12. Fungal Partnerships
Fungi form mutualistic symbiotic associations to form lichens and mycorrhizae
LICHEN
An association between fungus and a photosynthetic partner such as cyanobacteria or algae
MYCORRHIZA
An association between fungi and the roots of nearly all plants

13. Fungi and Industry, Ecosystem, and Disease (cont.)
Fungi are used for food, medicines, research, alternative fuels, and pest control.
FOOD: mushrooms; blue cheese; yeast in baking, brewing, and winemaking; produce citric acid found in soft drinks and candy
MEDICINES: produce antibiotics like penicillin; bread mold makes cortisone (used to treat skin irritations); yeast has been used to make vaccines for Hepatitis B
ALTERNATIVE FUELS: yeast produce gasohol (gasoline alternative)
FUNGAL INSECT PESTICIDES: reduces the need for harmful/toxic pesticides on crops

14. Fungi and Industry, Ecosystem, and Disease
Fungi play important ecological roles by decomposing organic matter and by breaking down and absorbing minerals from rocks and soil.
Fungi cause disease by absorbing nutrients from host tissues and by producing toxins.
Fungi can grow on and inside tissues of the body and therefore can be difficult to cure
DERMATOPHYTES – fungi that infect the skin and nails
(ex: Athlete’s Foot, Toenail Fungus, and Ringworm)
Yeast Infections – occur on reproductive organs and mouth
Toxins produced by fungi can cause vomiting, diarrhea, liver damage, cancer, and even death