CH 31: Fungi

Question 1

What are the evolution and distinctive features of fungi?

Answer 1

Part of Eukaryote supergroup Opisthokonta

More closely related to animals than plants

• Heterotrophic
• Absorptive nutrition
• Store surplus food as glycogen

Question 2

What is the only fungi without chitin cell wall?

Answer 2

Cryptomycota

Question 3

What is the cell wall chemistry of fungi?

Answer 3

Fungal cells enclosed by tough cell walls composed of chitin
-Different than animals

Cannot engulf food due to chitin

Also restricts mobility

Question 4

What is Hyphae?

Answer 4

Colorless threads that branch to make up main body of most fungi

Question 5

What is mycelium?

Answer 5

Vast number of hyphae that grow together to make up a tangled web (this is the main body)

Question 6

What are the different body forms of fungi?

Answer 6

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

Question 7

How does fungi grow?

Answer 7

• Grows quick when food plentiful
• Grows at edges
• Narrow branches provide high surface area for absorption
• Osmosis causes hyphae to grow outwards

Question 8

How do fungi reproduce asexually?

Answer 8

Produce asexual clone spores

Ideal for rapid spread

• don’t need to find a mate
• no fruiting body
• no meiosis

Question 9

How do fungi reproduce sexually?

Answer 9

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)

Question 10

What are the fruiting bodies of fungi?

Answer 10

Contains dikaryotic cells that fuse when mature

Produce zygotes and undergo meiosis to produce haploid spores

Question 11

How do fruiting bodies deter consumption?

Answer 11

Toxins and hallucinogens

Question 12

What are the features of Cryptomycota?

Answer 12

• Lack Chitin

- Found in water/soil

Question 13

What are the features of Chytridiomycota?

Answer 13

• Water/soil

- decomposers/pathogens

Question 14

What are the features of Microsporidia?

Answer 14

• Small size

- Pathogens that need animal host to reproduce

Question 15

What are the features of Zygomycetes?

Answer 15

• Decomposers

- Bread mold

Question 16

What are the features of Arbuscular mycorrhizal fungi?

Answer 16

• Live with plant partners
• Aseptate hyphae
• Asexual reproduction
• Helped early plants live on land

Question 17

What are the features of Ascomycetes?

Answer 17

Sac-fungi

• Septate hyphae
• Sporangia called asci
• Decomposers/plant pathogens

Question 18

What are the features of Basidiomycetes?

Answer 18

Club fungi

• Septate hyphae
• most recently diverged froup
• mycorrhizal partners
• sexual spores called basidiospores

Question 19

What is the ecology of fungi?

Answer 19

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

Question 20

What is fungal association, Mycorrhizae?

Answer 20

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

Question 21

What is fungal association, endomycorrhizae?

Answer 21

Grow inside root cells to get nutrients

-don’t grow too deep into plant or else it will be killed

Question 22

What is fungal association, ectomycorrhizae?

Answer 22

Coat root surface and grows between root cells

Question 23

What is the fungal association, fungal endophytes?

Answer 23

Live within leaf and stem tissues of plant

• Fungal endophytes get organic molecules from plant
• Plant gets toxins/antibiotics for defense against herbivory/pathogens

Question 24

What is the fungal association, lichens?

Answer 24

partnership of certain fungi and photosynthetic green algae or cyanobacteria

• partner gets CO2, water, minerals
• fungi gets organic food molecules and oxygen