Lecture 9

Question 1

What is the largest organisms by area?

Answer 1

fungus

Question 2

Humongous Fungus

Answer 2

invades roots; through DNA fingerprinting has been determined one organisms spans over 1000 hectors

Question 3

Fungus as “Friend”

Answer 3

more benefits from fungus than harm

break down lignin and cellulose

Question 4

Fungi

Answer 4

• absorptive heterotroph
• decomposer (saprobes, saprotrophs)
• cell wall of chitin (poly-glucosamine) and glucans (polysaccharide)

Question 5

absorptive heterotroph

Answer 5

don’t synthesize, release enzymes into the environment that partially digests organic matter then draw nutrients in across cell wall

Question 6

saprobes

Answer 6

feed on dead organic matter

Question 7

chitin

Answer 7

poly-glucosamine

Question 8

glucan

Answer 8

polysaccharide

Question 9

Produce spores - Fungus

Answer 9

single cell that yields new organisms, disperse from parent and can live out unfavourable condition

Question 10

Fungus - similarities to plants and animals (3)

Answer 10

• multicellular (unicellular yeast budding)
• terrestrial
• produce spores

Question 11

Fungus - Filamentous (5)

Answer 11

• provide large surface area
• divided into cell-like components by porous septae
• cytoplasm is continuous
  hyphae - long branched filaments
  mycelium - tangled mass of hyphae

Question 12

mycelia (4)

Answer 12

mycelium (dense hyphae) 
mycelium of absorptive structure (spaced hyphae, to absorb more nutrients) 
fruiting body (capable of producing spores)

Question 13

Stucture

Answer 13

most fungus is underground

-above ground is a fruiting body

Question 14

fruiting bodies

Answer 14

• only small portion of biomass
• reproduction
• fairy ring

Question 15

symbiotic

Answer 15

commensal (+/0)
mutualistic (+/+)
parasitic (+/-)

Question 16

saprophytic

Answer 16

decomposer

Question 17

predatory

Answer 17

create loops as noose that tightens down on nematode that accidentally swam through it, then secretes enzymes into nematode for digestion

Question 18

How is fungus important to plant’s growth and survival?

Answer 18

mycorrhiza (mutualistic relationship with plant root)
fungus receives carb
plant receives minerals
plant grows bigger if with fungus

Question 19

endomycorrhiza

Answer 19

within plant root and cell(80%)

Question 20

ectomycorrhiza

Answer 20

hyphae extends into soil and cell wall but not cells

Question 21

Fungal hyphae in stem (When?)

Answer 21

• long history
• older than vascular plants
• Devonian period (385 MYA)

Question 22

Lichen with fungus

Answer 22

fungus + cyanbacterium/green algae

-given protection from desiccation (dryness) & algae provides photosynthetic products to fungus

Question 23

Lichen

Answer 23

• pioneer species in newly formed habitats
• sensitive to poison air
• breaks down rock to form soil
• tolerate extreme climates
• food for tundra
• diverse

Question 24

Lichen mutualistic relationship with leaf cutter ant

Answer 24

• feed fungal colony that breaks down cellulose
• hyphae feed to any
• ants provide protection

Question 25

Fungi - Pathogens (6)

Answer 25

- ring worms - ergot in rye - athlete's foot - thrush - tar spots - corn smut fungal infection are harder to treat than bacteria coz it's closer in relationship with animal

Question 26

spores of fungus

Answer 26

unicellular reproductive structure; asesually/ sexually

Question 27

mushroom gill

Answer 27

basidia - spores

Question 28

fungus - asexually (4)

Answer 28

- budding - fission - conidia (spores at the end of hyphae) - spores in sporangia disperse by air/water (puffball)

Question 29

Phylogeny of Fungi

Answer 29

- flourish by Permian period - closely related to animals than plants - domain of botanists for 100 years - 100,000 species

Question 30

Chytrid and Zygomecetes

Answer 30

potentially arises multiple times or some traits are lost, phylogeny is not clear

Question 31

Basidiomycota

Answer 31

mushrooms

Question 32

yeast

Answer 32

- unicellular - have plasmid (good for model for genetics) - belong to zygomecetes, basidiomycota, ascomycota

Question 33

microsporidia

Answer 33

- relationship to other eukaryotes have puzzled taxonomists for decades - Among smallest eukaryotic organisms - Unicellular - Lack mitochondria, but instead have mitosomes (derived from mitochondria, but lack DNA) - Obligate intracellular parasites

Question 34

Chytrides (paraphyletic)

Answer 34

- aquatic - 1000 species - flagellated gametes and spores (only group with motile stage) - unicellular and multicellular stage - saprobic, mutualistic, parasitic (affected frog epidermis, causing global decline of amphibians) - only fungi with alternating life cycle

Question 35

Zygomycota

Answer 35

- saprobic, parasitic, terrestrial - >1000 species - spores contained in sporangia astop specialized hyphae

Question 36

Zygomycota - reproduction cycle

Answer 36

- haplontic life cycle - Zygosporangium - resistant spore - dikaryotic cycle: cytoplasm fuse but not nuclei (plasmogamy) leads to this phase then nuclei fuse in karyogamy

Question 37

Glomeromycota

Answer 37

- >200 species - terrestrial - form arbuscular endomycorrhizae - transfer phosphorus to plants - no known sexual stage

Question 38

Basidiomycota (Club Fungi)

Answer 38

- terrestrial, aquatic - fruiting bodies = basidiocraps - 30,000 species - saprobes - ectomycorrhizae - only group able to digest lignin - rusts & smuts

Question 39

Basidiomycota (Club Fungi)

Answer 39

- diploid stage very short | - cytoplasm and nuclei fusion not parallel

Question 40

Ascomycota (Sac Fungi)

Answer 40

- terrestrial, aquatic - fruiting bodies with sacs: morels, truffles - 70,000 - conidia produced asexually in specialized hyphae - karyogamy before plasmogamy - Pseudogymnoascus destructans: cold-loving; important to conservation - fungal infection on bats: white nose syndrome