Kingdom Fungi
Chapter 22
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
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
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
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
Reproduction
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
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
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
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
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)
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
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
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