MIC 102 FINAL QUESTIONS & ANSWERS
Fungi: 3 major morphological groups - Answers -1. Multicellular filamentous molds
-old food/classic fungus
2. Multicellular fruiting body formers
-Fruiting bodies = Mushrooms (fungus is in the soil)
3. Yeasts
-single celled
Unique properties of Fungus: Cell wall - Answers -Thematically similar to bacteria &
archaea but contain differences eg:
-Chitin: protein; insect shells are made of this
-Mixed glycans: similar to peptidoglycan but in a dif order
Can also secrete glycocalyx on top; hard shell
Unique properties of Fungus: Cell membrane - Answers -In order to provide more rigid
shape, add in sterols
Primarily Ergosterol: Unique to fungi, required for plasma membrane structure and
function
Filamentous fungus (2 types) - Answers -Single filament = hypha
Multiple = mycelium
-Mushrooms are a reproductive mycelium
Fungal ecology - Answers --Incredibly common in soil
-A single fungus can spread incredible distances through its mycelium underground
-Fungi are major contributors to decomposition in environment; great at digesting
cellulose + lignin (bark)
Mycorrhizae (definition + 2 types) - Answers --symbiotic relationship with plants & fungi
-Tube system; allows plants to extend their weeds/roots
Types:
-Endo: grow into plant root
-Ecto: surround plant root
Common mycorrhizal network: definition + function - Answers --connect many species
of plants and fungi into a single network
-Can pass nutrients to plants, or
,-Can be used by plants to pass molecular signals to each other (can be different
species of plants)
Other things fungi can function in (4) - Answers --Antibiotics
-Statins (for high cholesterol)
-Food production
-Disease (difficult to treat because fungi are pretty closely related to us)
Filamentous fungal reproduction: Overview - Answers -Sporulate → start growing →
grow filaments as haploids → at some point one filament of one fungus might come
close to another filament of another fungus → grow together → fuse → fused mycelium
(2 nuclei) = dikaryon (kind of a diploid) → this grows → takes on classic mushroom
shape → environmental signals prompt nuclei to fuse = true diploid → immediately
undergo meiosis; produce new spores
Filamentous fungal reproduction: Spelled out - Answers -1. Haploid filaments grow
normally with asexual divisions
2. Filaments fuse and Dikaryon forms (one filament cell contains two nuclei)
3. In response to changing conditions, nuclei will fuse and form true diploid, which will
immediately undergo meiosis to produce spores
-Filamentous fungi (esp. mushrooms) can have thousands of different mating types;
many combinations are compatible for forming dikaryons (must be compatible mating
types)
Spore formation: 2 main types - Answers -Varies from species to species; 2 main
types:
1. Ascomycetes
2. Basidiomycetes
Can make observations based on morphology that match up with phylogenetics
Ascomycetes - Answers -(found in yeasts and non-mushroom forming molds)
An ascus with 8 spores
-A single diploid cell undergoes meiosis and produces 4 unique spores
-Those 4 spores undergo mitosis, end up with a total of 8 spores in a pack called an
ascus
Basidiomycetes - Answers -(mushrooms and other filaments)
-Basically bud off "freely shed" spores from meiotic (former) dikaryons
-Constantly being made and shed; not packaged up
, Yeast reproduction: general idea - Answers -Technically ascomycetes but do things a
little differently
Can reproduce via asexual budding (like filamentous fungi) but limited this way because
each budding forms a scar; once scar is formed you can't bud from that spot
Yeast reproduction: S. cerevisiae - Answers --Haploid cells, can reproduce asexually or
sexually
-2 haploid mating types, a and α
-As long as a and alpha are close enough together they will fuse = 1 diploid cell
-Diploid cell can reproduce asexually by budding too
-Nutrient limitation induces sporulation of a diploid cell
-Meiosis of diploid produces 4 haploid spores
STOPS HERE: Haploid does not undergo mitosis; ascus only holds 4 spores (=tetrad)
-2 of each mating type
-Spores germinate under appropriate conditions (Can be just 1 spore or all at the same
time)
How does S. cerevisiae ensure survival with only 2 of each mating type? - Answers -
Haploids can switch mating types (a to α or vice versa) by switching which gene is
expressed
Control of mating types - Answers --Mating type is entirely determined by the
expression of one gene
-Exist silently: No promoter in front of them in standard locations
-Either a or α gene can be copied into the MAT expression site where it will be
expressed
= whichever copy you put in front of it, that's what gets expressed, that's what mating
type you are
Protists: broad definition - Answers -Diverse, generally unicellular eukaryotes
4 major groups of protists - Answers -1. Flagellates
2. Amoeboids
3. Ciliates
4. Apicomplexa
Amoeboids: quick overview - Answers -Undefined shape
Use pseudopodia to get around
Feeding: Phagocyotsis
Example: N. fowleri (encephalitis)
Fungi: 3 major morphological groups - Answers -1. Multicellular filamentous molds
-old food/classic fungus
2. Multicellular fruiting body formers
-Fruiting bodies = Mushrooms (fungus is in the soil)
3. Yeasts
-single celled
Unique properties of Fungus: Cell wall - Answers -Thematically similar to bacteria &
archaea but contain differences eg:
-Chitin: protein; insect shells are made of this
-Mixed glycans: similar to peptidoglycan but in a dif order
Can also secrete glycocalyx on top; hard shell
Unique properties of Fungus: Cell membrane - Answers -In order to provide more rigid
shape, add in sterols
Primarily Ergosterol: Unique to fungi, required for plasma membrane structure and
function
Filamentous fungus (2 types) - Answers -Single filament = hypha
Multiple = mycelium
-Mushrooms are a reproductive mycelium
Fungal ecology - Answers --Incredibly common in soil
-A single fungus can spread incredible distances through its mycelium underground
-Fungi are major contributors to decomposition in environment; great at digesting
cellulose + lignin (bark)
Mycorrhizae (definition + 2 types) - Answers --symbiotic relationship with plants & fungi
-Tube system; allows plants to extend their weeds/roots
Types:
-Endo: grow into plant root
-Ecto: surround plant root
Common mycorrhizal network: definition + function - Answers --connect many species
of plants and fungi into a single network
-Can pass nutrients to plants, or
,-Can be used by plants to pass molecular signals to each other (can be different
species of plants)
Other things fungi can function in (4) - Answers --Antibiotics
-Statins (for high cholesterol)
-Food production
-Disease (difficult to treat because fungi are pretty closely related to us)
Filamentous fungal reproduction: Overview - Answers -Sporulate → start growing →
grow filaments as haploids → at some point one filament of one fungus might come
close to another filament of another fungus → grow together → fuse → fused mycelium
(2 nuclei) = dikaryon (kind of a diploid) → this grows → takes on classic mushroom
shape → environmental signals prompt nuclei to fuse = true diploid → immediately
undergo meiosis; produce new spores
Filamentous fungal reproduction: Spelled out - Answers -1. Haploid filaments grow
normally with asexual divisions
2. Filaments fuse and Dikaryon forms (one filament cell contains two nuclei)
3. In response to changing conditions, nuclei will fuse and form true diploid, which will
immediately undergo meiosis to produce spores
-Filamentous fungi (esp. mushrooms) can have thousands of different mating types;
many combinations are compatible for forming dikaryons (must be compatible mating
types)
Spore formation: 2 main types - Answers -Varies from species to species; 2 main
types:
1. Ascomycetes
2. Basidiomycetes
Can make observations based on morphology that match up with phylogenetics
Ascomycetes - Answers -(found in yeasts and non-mushroom forming molds)
An ascus with 8 spores
-A single diploid cell undergoes meiosis and produces 4 unique spores
-Those 4 spores undergo mitosis, end up with a total of 8 spores in a pack called an
ascus
Basidiomycetes - Answers -(mushrooms and other filaments)
-Basically bud off "freely shed" spores from meiotic (former) dikaryons
-Constantly being made and shed; not packaged up
, Yeast reproduction: general idea - Answers -Technically ascomycetes but do things a
little differently
Can reproduce via asexual budding (like filamentous fungi) but limited this way because
each budding forms a scar; once scar is formed you can't bud from that spot
Yeast reproduction: S. cerevisiae - Answers --Haploid cells, can reproduce asexually or
sexually
-2 haploid mating types, a and α
-As long as a and alpha are close enough together they will fuse = 1 diploid cell
-Diploid cell can reproduce asexually by budding too
-Nutrient limitation induces sporulation of a diploid cell
-Meiosis of diploid produces 4 haploid spores
STOPS HERE: Haploid does not undergo mitosis; ascus only holds 4 spores (=tetrad)
-2 of each mating type
-Spores germinate under appropriate conditions (Can be just 1 spore or all at the same
time)
How does S. cerevisiae ensure survival with only 2 of each mating type? - Answers -
Haploids can switch mating types (a to α or vice versa) by switching which gene is
expressed
Control of mating types - Answers --Mating type is entirely determined by the
expression of one gene
-Exist silently: No promoter in front of them in standard locations
-Either a or α gene can be copied into the MAT expression site where it will be
expressed
= whichever copy you put in front of it, that's what gets expressed, that's what mating
type you are
Protists: broad definition - Answers -Diverse, generally unicellular eukaryotes
4 major groups of protists - Answers -1. Flagellates
2. Amoeboids
3. Ciliates
4. Apicomplexa
Amoeboids: quick overview - Answers -Undefined shape
Use pseudopodia to get around
Feeding: Phagocyotsis
Example: N. fowleri (encephalitis)
