Chapter 31 Notes
Fungi
Concept 31.1
All fungi are eukaryotic; most are
multicellular
mycete = fungi
Fungi differ from plants in nutritional
mode, structural organization, growth,
and reproduction
Concept 31.1
Fungi are heterotrophs that acquire their
nutrients by absorption
- fungi digest their food outside their
body by secreting powerful hydrolytic
enzymes (exoenzymes) into the food.
- decomposers, parasites, and
mutualistic symbionts
Concept 31.1
Fungi have a large surface area and grow
rapidly to assist with absorption
The bodies of fungi are constructed of
tiny filaments called hyphae
- the hyphae are divided into cells by
cross-walls, or septa
- cells walls are made of chitin
Concept 31.1
Concept 31.1
Concept 31.2
Fungi disperse and reproduce by
releasing spores that are produced
sexually and asexually
- heterokaryotic stage: fusion of two
hyphae that have genetically different
nuclei
Concept 31.2
Concept 31.4
Concept 31.4
More than 100,000 fungi are known;
estimated that 1.5 million may exist
Phylum Chytridiomycota:
- chytrids are mainly aquatic
- saprobes or parasites
- most primitive fungi; ancestors of
protists
Concept 31.4
Phylum Zygomycota:
- mostly terrestrial; live in soil or on
decaying plants and animals
- many form mycorrhizae, a
mutualistic association with the roots of
plants
Concept 31.4
Concept 31.4
Phylum Ascomycota:
- sac fungi
- range from unicellular yeasts to cup
fungi
- produce spores in saclike asci
Concept 31.4
Phylum Basidiomycota:
- “club fungus”
- mushrooms, puffballs, and rusts
- important decomposers of wood and
other plants
Concept 31.4
Concept 31.5
Molds, yeasts, lichens, and mycorrhizae
have specialized lifestyles
Molds
- a rapidly growing, asexually
reproducing fungus
Yeasts
- unicellular fungi that inhabit liquid or
moist habitats
Concept 31.5
Concept 31.5
Concept 31.5
Lichens
- symbiotic relationship of millions of
photosynthetic microorganisms held in
a mesh of fungal hyphae
- the alga provides the fungus with
food. The fungus provides a suitable
environment for growth
Concept 31.5
Concept 31.5
Concept 31.5
Mycorrhizae
- mutualistic association of plant roots
and fungi
- responsible for making nutrients able
to be absorbed
Concept 31.5
Concept 31.5