CH 31: Fungi Flashcards
What are the evolution and distinctive features of fungi?
Part of Eukaryote supergroup Opisthokonta
More closely related to animals than plants
- Heterotrophic
- Absorptive nutrition
- Store surplus food as glycogen
What is the only fungi without chitin cell wall?
Cryptomycota
What is the cell wall chemistry of fungi?
Fungal cells enclosed by tough cell walls composed of chitin
-Different than animals
Cannot engulf food due to chitin
Also restricts mobility
What is Hyphae?
Colorless threads that branch to make up main body of most fungi
What is mycelium?
Vast number of hyphae that grow together to make up a tangled web (this is the main body)
What are the different body forms of fungi?
Hyphae Aseptate (early diverging fungi) -"no septa", no division between nuclei in hyphae
Hyphae Septate (later diverging fungi) -septa divides hyphae into sections with one nucleus
Fruiting bodies
-reproductive structures that produce spores
How does fungi grow?
- Grows quick when food plentiful
- Grows at edges
- Narrow branches provide high surface area for absorption
- Osmosis causes hyphae to grow outwards
How do fungi reproduce asexually?
Produce asexual clone spores
Ideal for rapid spread
- don’t need to find a mate
- no fruiting body
- no meiosis
How do fungi reproduce sexually?
Gametes fuse, form zygote, meiosis
Gametes are cells from hyphal branches
-hyphal branches fuse
Plasmogamy (gamete cytoplasm fuse) followed by karyogamy (gamete nuclei fuse)
Nuclei remain separate for long time after plasmogamy as dikaryons (two nuclei)
What are the fruiting bodies of fungi?
Contains dikaryotic cells that fuse when mature
Produce zygotes and undergo meiosis to produce haploid spores
How do fruiting bodies deter consumption?
Toxins and hallucinogens
What are the features of Cryptomycota?
- Lack Chitin
- Found in water/soil
What are the features of Chytridiomycota?
- Water/soil
- decomposers/pathogens
What are the features of Microsporidia?
- Small size
- Pathogens that need animal host to reproduce
What are the features of Zygomycetes?
- Decomposers
- Bread mold
What are the features of Arbuscular mycorrhizal fungi?
- Live with plant partners
- Aseptate hyphae
- Asexual reproduction
- Helped early plants live on land
What are the features of Ascomycetes?
Sac-fungi
- Septate hyphae
- Sporangia called asci
- Decomposers/plant pathogens
What are the features of Basidiomycetes?
Club fungi
- Septate hyphae
- most recently diverged froup
- mycorrhizal partners
- sexual spores called basidiospores
What is the ecology of fungi?
Decomposers
- can break down cellulose and lignin
- release minerals to soil and water
Some are:
- predators: lasso fungi
- parasites: cordyceps
- pathogens: athletes foot or crop rust
What is fungal association, Mycorrhizae?
Association between hyphae of certain fungi and roots of most seed plants
- plants receive more water/minerals
- fungi receive organic food molecules
Types are endomycorrhizae and ectomycorrhizae
What is fungal association, endomycorrhizae?
Grow inside root cells to get nutrients
-don’t grow too deep into plant or else it will be killed
What is fungal association, ectomycorrhizae?
Coat root surface and grows between root cells
What is the fungal association, fungal endophytes?
Live within leaf and stem tissues of plant
- Fungal endophytes get organic molecules from plant
- Plant gets toxins/antibiotics for defense against herbivory/pathogens
What is the fungal association, lichens?
partnership of certain fungi and photosynthetic green algae or cyanobacteria
- partner gets CO2, water, minerals
- fungi gets organic food molecules and oxygen
