Lab 3: Fungi Flashcards
In what form do all fungi grow?
hyphae
- single hypha
what is hyphe?
In fungi, long narrow strand of cells which makes up the body of a fungus.
* branched, tubular, thread-like strands that give fungus a fuzzy appear
- even compact mushrooms are composed of these
what are a group of hyphae in a fungus called?
mycelium
what is mycelium?
the body of a fungus which is composed of many hyphae
- a group of hyphae
are fungi mostly unicellular or multicellular?
mostly multicellular
Are fungi prokaryotic or eukaryotic?
eukaryotic
are fungi autotrophic or heterotrophic?
heterotrophic
what are fungi known to be?
Major decomposers (especially plant material)
- unlike other decomposers; can degrade cellulose & lignin (major components of plant cell walls)
- make nutrients available for recycling in the ecosystem
Why are fungi considered Saphrobes?
they are heterotrophic organisms that use extacellular digestion to get their energy by breaking down dead or decaying organic material (ie. secrete digestive enzymes into it and absorbing the products of digestion)
- decomposers
- breakdown larger mol. into smaller absorbable ones
what does the suffix -mycota mean?
organism of the phylum fungi
what are the 4 major phyla of fungi?
- Chytridiomycota
- Zygomycota
- Ascomycota
- Basidiomycota
Do fungi have motile or non-motile reproductive cells?
Non-motile reproductive cells
- exception: phylum Chytridiomycota (produce flagellated gametes during sexual reproduction)
How do members of the phylum Zygomycota, Ascomycota, & Basidiomycota reproduce sexuall?
Produce non-motile gametes thus:
- hyphae of 2 mating strains grow towards each other and fuse to produce a reproductive structure
- Zygomycota: fusion of hyphae — zygospore (resistant)– meiosis – spores
- Asomycota: fusion of hyphae – ascocarp (contains asci) – meiosis – spores
- Basidomycota: fusion of hyphae – basidiocarp (mushroom) – basidia on gills surface – meiosis – basidiospores
are most fungi terrestrial or aquatic?
terrestrial (some aquatic)
Do fungi contains chlorophyll?
NO - lack chlorophyll as they are heterotrophs
what kind of cell wall do the dominant stages of fungi have?
cell wall made of Chitin
- thus they can’t ingulf their food (ie. are saphrobes that do extracell
how did fungi evolve?
evolved along with plants to eploit terrestial habitats
What are 2 ways that fungi use to live?
- As symbionts - live in close assocaitions with other organisms where both organims benefit (eg. with plant roots)
- As parasites (live in or on the bodies of plants or animals and benefit at their expense)
- As pathogens that cause disease
Symbionts
live in associations with another organism where both organisms benefit
Lichens
association of fungi with algae
- symbiont relationship of fungi with algae
mycorrhizae
A mutualistic association b/w fungi of either phylum Zygomycota or the phylum Basidiomycota and the roots of plants
Fungi grows in and around the plants roots
Plant benefits:
- aids in water & mineral uptake by the plant
- provides protection to plant roots from the environment & parthogenic organisms
Fungi benefits:
- provides fungi water & nutrients from plant roots
Why do fungi have few adaptations against dessication in dry environment?
- have few adaptations
- grow within their food source and use its moisture + moisture from environment (soil/leaf littter)
What do fungi do if their environment dries out?
quickly produce spores which are waterproof and can remain dormant for years
what do fungi do when moist conditions return?
release spores which land on a food source to germinate and grows into hyphae
when are fungi conspicuous?
- easily seen
when undergoing sexual reproduction
what structural adaptations do fungi have in terms of their sexual structures?
elevated or exposed sexual strucutres so that the spores released can be dispersed by air currents
- ex. mushroom is a reproductive structure above the soil with haphae network underneath
How do most fungi reproduce?
Asexual: fragmentation of the mycellium or by production of asexual spores
Sexual: fusion of gametes from 2 diff. mating strains of the same species of fungus (usually involves sexual spores for dispersal)
- gametes produced by gametangia
sexual vs asexual spores
Sexual spores result from the fusion of nuclei and promote genetic diversity, while asexual spores are genetically identical to the parent organism.
sexual spores: Basidiospores (e.g. mushrooms) and ascospores (e.g., sac fungi).
asexual spores: sporangiospores (e.g., Rhizopus)
Chytridiomycota: They primarily produce asexual spores called zoospores
Zygomycota: produce both sexual (zygospores) and asexual (sporangiospores) spores
Ascomycota: This phylum produces sexual spores called ascospores, often contained within sac-like structures called asci.
Basidiomycota: They primarily produce sexual spores called basidiospores, which are formed externally on structures called basidia. Basidiomycota fungi typically lack a well-defined asexual stage.
How are fungi divided/grouped?
- presence or absence of cross walls (septa) in thier hyphae
- type of seuxal reproductive structures
Septa
cell walls which divide the hypha into distinct cells
Septa are … hypha
which phylum?
Uninucleate
phylum: Ascomycota & Basidiomycota
- have cell walls
Asepta are …. hypha
which phylum?
Multinucleate (more than 1 independent nuclei)
Phylum: Chytridiomycota & Zygomycota
- no cell walls; single-celled hypha
Characteristics of the Phylum Chytridiomycota (Chytrids)
- mostly aquatic
- aseptate; multinucleated hyphae
- most primitive
- only group that produce motile gametes for sexual reproduction
- produce motile spores
- septae only present at bases of reproductive strucutres and may be present in older or injured hyphae
- some may live in soil or be parasites of algae or plants
Allomyces
Domain: Eukaryoa
Kingdom: Fungi
Phylum: Chytridomycota
Genus: Allomyces
Common name: water mold
- used to be classified as Blastocladiales
Habitat of Allomyces
small bodies of freshwater
- found world-wide