Topic 1 Flashcards
What is the role of fungi?
Essential for the well-being of most terrestrial ecosystems
Break down organic material (leaves, wood, bones, rotting bodies etc.)
Recycle vital nutrients & make nutrients available to other organisms (N, C & P)
What nutrients does fungi recycle?
N, C & P
What are some fungi separated by?
Septa
What do pores enable?
cell - to - cell movement –> exchange of cytoplasm & organelles
Up take nutrients & move them to the tips of hyphae to grow
Coenocytic fungi
lack septa
attack sugar rich substrates
hype grow fast
Move material to the tips of the hype to build material around the cell wall
What is the composition of fungal cell walls in most fungi?
chitin (polysaccharide) & other polysaccharides (ex: cellulose)
Chitin has a bit of PRO –> N component
Mycelia
networks of branched hyphae
branched hyphae –> adapted for absorption
or
pseudo “tissues” –> sexual structures
Hymenium
region on the mushroom where meiosis occurs
What do the cells of the fruiting bodies develop into?
Basidia or ascus –> Sexual spores
Why do we refer to the sexual structures as pseudo “tissues”?
No germ cells –> not true tissues
How are fungi classified in an ecosystem?
heterotrophs
absorb nutrients, don’t ingest
How do fungi uptake nutrients?
Secrete exoenzymes
break down nutrients
absorb smaller compounds
What are the 4 lifestyles of fungi?
Decomposers (Saprotrophs)
Parasites
Necrotrophs
Mutualistic symbionts
Decomposer (saprotroph)
perform essential recycling of chemical elements b/w the living & non-living world
-Use exoenzymes & excretes materials that other organisms can use
Parasites
Feeds on living material, tissues or body fluids of another species while in or on a host, harm but don’t kill host
living on living material
30% of all fungi
Necrotrophs
feed on host & then switch to a saprotroph once the host is dead (kill living host cells)
Mutualistic symbionts
symbiotic relationship where both parents benefit
lichens: assoc with fungal & algae
- Most mushrooms, form assoc with roots micohizas
What organisms does fungi form symbiotic relationships with?
plants
algae
animals
Ectomycorrhizae
mutually beneficial relationships b/w fungi & plant roots
- Importance natural ecosystems & agriculture - Incres plant productivity Incres the absorption of phosphorus & other needed minerals - Plant provides C & mushroom provides nitrogen N cycling - Mushroom connects from one tree to another, creating water movement
Endomycorrhizae
arbuscular mycorrhizae (glomeromycetes) highly branched feeding structures in the cell space (not in cell membrane)
- Nutrient exchange across membrane systems - From plant into fungus & vice versa - Don’t penetrate cell, cell forms around the arbuscular
What phylum forms endomycorrhizae?
glomeromycetes
arbuscular mycorrhizae
What is an ex of fungus-animal relationship?
break down plant material in the guts of cows & grazing mammals
animal provides C
&
Fungi provides nutrients
Ants –> take advantage of digestive power by raising fungi in farms
lichen
degrade lithic (rock) & lignicolous (wood) substrates to initiate soil formation
Symbiotic relationship of photosynthetic organisms help in fungal hyphae
What are the parts of lichens?
Fungal component –> often a sac fungus (Ascomycete) forms an outer covering & skeletal framework
Algae or cyanobacterium–> occupy an inner layer below the lichen surface
How do lichens reproduce?
Sexually (ascus)
OR
Asexually (soredia)
What is the role of mycelium?
Gather & absorb nutrients to grow & produce mushrooms
What is an ex of parasitic fungi?
Fungi parasitizing a nematode
Hyphae form constricting rings, nematode moves through the soil where these rings are & becomes trapped
Hyphae enables penetration of the tissues –> form haustoria
Haustoria
PENETRATES protoplasm of a cell & feeds on cell contents
Acquires enough nutrients to form spores
What are the 2 forms of sexually spore forming structures?
Basidiocarp
Ascocarp
What are the 2 forms of assexually spore forming structures?
Soredia
Isidia
What does a dikaryote in the sexual life cycle represent?
plasogamy has already occurred
Where does reproduction occur in a fungi?
Septa
When does basidium form?
2 nuclei form via karyogamy –> zygote
Plasogamy
cell fusion
Karyogamy
nuclear fusion
What part of the sexual life cycle is occurring when you have a haploid nuclei from 2 parents?
intervening heterokaryotic stage b/w plasmogamy & karyogamy
What stage only occurs in mushrooms?
Dikaryotic stage
How many nuclei does the hyphae that make up the fruiting body usually have?
monokaryotic (usually)
What restricts a dikaryon’s growth?
Asci
What are the asexual products & processes?
- Produce mitospores
- Hyphal fragments
- Specialized thallus structures –> soredia & asidia
- Budding (spores)
- Fission (spores) etc.
- Spores are specialized to be either budded off or undergo fission
What do asexual fungi include?
mold
yeasts
How do yeasts reproduce?
simple cell division (budding & fission)
What term is used to identify that no recognized sexual stage? & what are those fungi?
Deuteromycetes or imperfect fungi
molds & yeasts
Anamorph
asexual stage of a known sexually reproducing fungi
Telomorph
fungi named for their sexual stage in case of known sexual & asexual stages
What type of spores do sporangium release?
haploid
What does molecular evidence display that fungi & animals diverged from?
unicellular & had flagella
Fungi were the earliest colonizers of land as symbionts with which organisms?
land plants
What type of fungi were the first to come to land?
Unicellular living as endomychorizhae
Where are Chytrids located?
freshwater & terrestrial habitats
What is the type of lifecycle of a chytrid?
saprotrophic
parasitic
Zoosporic
mobile, flagellated asexual spore
What is unique about the Chytrids?
flagellated spores called zoospores
What kind of lifecycles are found in the Zygomycota?
molds
parasites
saproptrophic
symbionts
What lifecycle processes occur on the zygosporangia?
plasmogamy
karyogamy
meiosis
What phylum does Pilobus belong to? & how does it release spores
Zygomycota
sporangium sit on vesicles filled with water, the vesicles accumulate with water & then burst releasing the spores
aim sporangium toward conditions with good food sources
What is zygosporangium resistant to?
freezing & drying
What phylum consists of endomycorrhizae & what is it called?
Glomermycota
arbuscular mycorrhizae
What phylum did Glomeromycota used to be classified under?
zygomycetes
What type of lifecycle does glomermycetes have?
symbiotic
What is the habitat for ascomycetes?
marine
freshwater
terrestrial
Asci
short-lived diploid phase during the lifecycle & undergoes meiosis forming haploid spores
How do ascomycetes reproduce?
Producing asexual spores called conidia
budding or splitting
specialized thallus structures (lichens)
Basidium
transient diploid stage in the life cycle
What process of the lifecycle occur in basidia?
karyogamy & meiosis
How many sterigma are formed on a basidium?
4
Annulus
remnants of partial veil associated with the stipe
Universal veil
temporary membrane structure covering immature fruiting bodies
What are the remanant structure of the universal veil?
Volva
remnants on the pileus
What are the remanant structure of the partial veil?
stem ring
annulus
partial veil
tissue found on the fruiting body of Basidiomycota, covers from the stem to the edge of the cap
Stem ring
Remnant structure of the partial veil
partial veil disintegrates once fruiting body is mature & releases spores, remnant structure is a stem ring
Volva
cap structure associated at the bottom of the stipe, remnant structure of the universal veil
Pili Pileus
covers top of pileus
Puffballs used to be classified under what phylum
glomeromycota
What is unique about the puffballs?
don’t have gills, spororcarp is located on the inside
Polypores
bracket fungi which contains spores or tubes on the underside of the cap
Somatogamy
sexual reporduction where 2 nuclei fuse
septum
cross walls that divide fungal hypha cells, have pores large enough to allow cell-to-cell movement of cytoplasm & organelles
soredia
small cluster of fungal hyphae with embedded algae
isidia
outgrowth from the surface of the thallus in certain lichens that resemble a soredium
basidia
reproductive appendage that produces sexual spores on the gills of mushrooms
basidiocarp
fruiting body of a dikaryotic mycelium of a club fungus
ascocarp
fruiting body of a sac fungi
plasmogamy
in cells, the fusion of the cytoplasm of cells from 2 indivs, occurs as one stage of sexual reproduction followed later by karyogamy
sterigma
slender stalks at the top of basidium of from the tips of where of which the basidiospores are produced
fission
the separation of an organism into 2 or more indvs of approximately equal size
Deutromycetes
any fungi in the class of imperfect fungi
zygosporangia
in zygomycete fungi, a sturdy multinucleate structure in which plasmogamy, karyogamy & meiosis occur
gametangia
mycelia of different mating types form hyphal extensions enclosing haploid nuclei
sporangium
multicellular organ in which meiosis occurs & haploid cells develop
clade
genetically distinct grp
conidia
haploid spore produced at the tip of specialized hypha in ascomycetes
probasidia
a cell in which two haploid nuclei fuse to form a diploid nucleus from which the basidium arises in some basidiomycetes
basidia of where karyogamy occurs
metabasidia
basidia whre meiosis occurs
homobasidiomycota
fungi that are not divided by septae
heterobasidiomycota
fungi that are divided by septae
peridium
protective layer that encloses a mass of spores
