fungi lecture 16 Flashcards
what do the cell walls of fungi contain
chitin
are fungi autotrophs or heterotrophs
heterotrophs (absorb food)
what do fungi secrete
exoenzymes: (break down to easier absorbe nutrients)
- enzymes released into the environment,
- breakdown large molecules into smaller more soluble forms that then get
absorbed
what is particular about fungi generations
- two seperate free-living organisms in the same generation
- gametophyte : haploid
- sporophyte : diploid
are fungis uni or multi cellular
range from unicellular (yeast) to multicellular (mushrooms)
what are bodies of fungai made of
tiny filaments called hyphae
what is the use of hyphae
increased surface area for absorption
what is mycelium
- filamentous body (mat of hyphae)
- usually hidden (below ground)
- like the roots
(look at picture on slide)
how to fungi disperse
- they produce spores
- carried by wind and water
what was the name of one of the largest fungi discovered
- Armillaria bulbosa
- 2000
what is the fruiting body
fleshy, spore baring part of the mushroom
In what way do fungi reproduce
both sexually and asexually
explain the asexual reproduction
- mushroom (fruiting bodies) release spores
- sporulation
- spores are dispersed by wind
- when they land on a suitable environment they produce mycelium
underground - adult mushroom grows up from the mycelium
explain the sexual reproduction
- Generally, the life cycle involves the fusion of hyphae
from two individuals (plasmogamy) - forming a mycelium that contains haploid nuclei of both
individuals. - Eventually the 2 nuclei that originated from different
individuals fuse to form a diploid zygote - Meiosis can then produces four haploid cells
what are fungi primary role in the ecosystem
decomposers
Recycle nutrients in ecosystems
Many species involved in:
* Break down of wood & leaves
* Some nutrients absorbed & used
* Rest returns to soil recycled by plants
* Slow process – could take years
how long does the decomposing process take
Temperate forests: 4-6 years
Tropical forests: few months to years
what is the second ecological significance of fungi
pathogens
* Some cause disease in plants reduce yield or kill plants
* fruit - especially berries
* vegetables: potatoes, root crops, corn, grain
*Some cause disease in animals including humans.
ex: Athlete’s foot, Jock itch, Yeast infections, Nail infections and respiratory
diseases (ex.mold problems in hospitals, schools)
(check slides)
what is apergilloma
fungus ball that colonizes in a healed lung scar or abscess from a previous desease
what cause fungi in buildings
- toxigenic fungi produce mycotoxins (they do not invade tissues)
- Spores and mycelial
fragments carry the
toxins - vehicles for their inhalation
what is the third ecological signifiance of fungi
mutualistic symbionts
what are the mutualistic symbionts between fungus and green algae or cyanobacteria
lichens: association between a fungus and a green algae (or cyanobacteria)
*check slides for structure
what is the relationship between the fungus and the algae or cyanobacteria, what do they bring to each other
Alga provides fungus with food
(organic carbon)
fungus provides alga with a suitable
physical environment for growth
what are the mutualistic symbionts between fungus and plant
Mycorrhizae = Association between a
fungus and a plant
*found on roots of over 90% of all
vascular plants
what is the relationship between the fungus and the plant, what do they bring to each other
- Fungus acquires carbon from plant
- plant gets nutrients, water, minerals,
pathogen resistance, increased
resistance to toxic elements in the
soil
