Topic 4: Unikont Diversity I (Fungi)

Question 1

What came first? Fungi or plants?

Answer 1

FUNGI

Question 2

Before plants, what did Earth look like?

Answer 2

“green slime” terrestrial life

• cyanobacteria
• algae
• small heterotrophs including fungi

Question 3

What is the shared derived trait of fungi related to nutrition?

Answer 3

absorptive heterotrophy

Question 4

What are the 3 steps of absorptive heterotrophy?

Answer 4

1. hyphae secrete hydrolases (hydrolytic enzyme)
2. hydrolases externally digest polymers -> monomers
3. Hyphae absorb small organic molecules

Question 5

What is the shared derived trait of fungi related to structure?

Answer 5

chitinous cell wall

Question 6

What is chitin? Characteristics of chitin?

Answer 6

N-containing polysaccharide

strong and flexible; very durable

Question 7

Is fungi multicellular or unicellular?

Answer 7

BOTH

mostly multicellular but some are unicellular

Question 8

What are the 2 structural characteristics of multicellular fungi? What are they and what do they do?

Answer 8

1. hyphae: long-branched, thread-like filaments
   - basic building block of fungus body
   - tubular cell wall surrounds plasma membrane
   - grows longer -> allows fungi to expand towards new food source
2. mycelium: tangled mass of hyphae
   - feeding network that grows around and within food source

Question 9

What are the characteristics of a spore? What do they do?

Answer 9

haploid
sexual or asexual
non-motile
land in moist place with food -> germinate -> new mycelium

Question 10

What are spores produced by? What do each of these do?

Answer 10

1. aerial hyphae: specialized to increase spore dispersal

2. fruiting bodies: complex, multicellular reproductive structure (e.g. mushrooms)

Question 11

How do fungi go through sexual reproduction?

Answer 11

they have mating types instead of male/female

Question 12

What is a mating type?

Answer 12

alleles coding for certain pheromone receptors

Question 13

How does sexual reproduction occur through mating types? What does this lead to?

Answer 13

only fungi with different mating types can reproduce with each other
this leads to genetic variation

Question 14

What are the steps of fungal mating?

Answer 14

1. Hyphae (n) release and detect pheromones
2. Hyphae extend towards source of other pheromones
3. If different mating types, meet and fuse cytoplasm, but not nuclei

Question 15

What is plasmogamy?

Answer 15

cytoplasmic fusion

Question 16

What is heterokaryon? Haploid/diploid? What is it produced from?

Answer 16

a fused mycelium with different nuclei
(n + n) - neither haploid or diploid
produced as a result of plasmogamy

Question 17

What happens after plasmogamy?

Answer 17

heterokaryon divides and grows (with two types of nuclei/cell) via MITOSIS

Question 18

What is karyogamy? What does it lead to?

Answer 18

nuclear fusion -> zygote with 2n ploidy

Question 19

What are the 2 main types of asexual reproduction? How do they reproduce?

Answer 19

1. Filamentous fungi - spores via mitosis

2. Single-celled yeast - spores via cell division or budding

Question 20

What are the 3 types of ecological fungi?

Answer 20

Decomposers
Parasites
Mutualists

Question 21

What does a decomposer do? What if there weren’t any decomposers?

Answer 21

absorb nutrients from non-living organic material
no decomposers = NO LIFE
- nothing to break down and recycle inorganic nutrients

Question 22

What does a parasite do?

Answer 22

absorb nutrients from cells of living hosts

ex: athlete’s foot, chytridiomycosis in frogs

Question 23

What does a mutualist do?

Answer 23

absorb nutrients from host organisms, but also benefit host

Question 24

What is an endophyte? Location? What does it do?

Answer 24

it is located on the inside of leaves

it deters herbivores

Question 25

What is a lichen? Where can you find it? What does it do?

Answer 25

fungus and photosynthetic microorganism provides a habitat for microbe growth; protection, retains water and nutrients can grow on rocks, trees, roofs

Question 26

What are some practical uses of fungi?

Answer 26

``` cosumption - truffles and morels - blue cheese - yeasts ferment sugars into CO2 and alcohol medical - antibiotic production ```

Question 27

What is a chytrid? Phylum? Ancestral character state? Derived character state? What is this considered in the phylogenic tree of fungi?

Answer 27

``` a terrestrial, freshwater, marine phylum: chytridiomycota has unique flagellated spores -> zoospores = ancestral character state flagella = derived character state it is a basal taxon ```

Question 28

What is a zygomycete? Phylum? What does it produce?

Answer 28

decomposer in soil phylum: zygomycota - > produces zoospores ex: black bread mold

Question 29

What is a glomeromycete? Phylum? What does it form?

Answer 29

found in about 80% of plant species phylum: glomeromycota - > forms glomerospores

Question 30

What phylum is ascomycetes in? Unicellular/multicellular?

Answer 30

``` phylum: ascomycota (ascospores) "sac fungi" largest number of known species very diverse; BOTH uni and multicellular ex: penicillium, morels and truffles, baking/brewing yeast, component of lichens ```

Question 31

What is basidiomycetes? Phylum? What does it form? Sexual/asexual?

Answer 31

``` many familiar decomposers phylum: basidiomycota forms basidiospores ALL sexual ex: bracket fungi, puff balls, wheat rust, corn smut, edible mushrooms ```

Question 32

What are fungi?

Answer 32

absorptive, heterotrophic eukaryotes