Exam 3 Flashcards
(58 cards)
Do fungi have genders?
They do not! Sexual cycles make no M/F gametes. They have no genders but instead are + or - mating types.
What are the three steps to form a zygote in fungal reproduction?
1) Plasmogamy - fusion of haploid (+) and (-) hyphae
2) Heterokaryotic stage - hyphae with unfused haploid nuclei of both types
3) karyogamy - fusion of +/- haploid nuclei to form zygote (2n)
Draw the life cycle/fungal reproduction cycle.
Check slide of cycles in the slideshow
What are Chytrids?
-basal fungus group
-Aquatic decomposers or parasites
- have flagella on their zoospores
What are zygomycetes?
- sexual cycle makes a resistant zygosporangium
- make asexual spores via mitosis called sporangiospores
- have coenocytic hyphae
What are glomeromycetes?
- mutualistic arbuscular mycorrhizae
-90% of plant species have a mycorrhizal relationship
What are ascomycetes?
- sexual spores within saclike ascus
- morels are really tasty
- asexual
What are basidiomycetes?
- has sexual spores within club-like basidium
- no asexual spores
- “mushrooms”
- has a lot of different shapes
What are the importances of fungi?
- medicine and research
- huge decomposers
- Symbioses - commensalism, mutualism
- Food
- property damage
What is the importance of fungi as decomposers?
they can break down the component of wood that most organisms cannot which is called lignin. It can feed on stumps of trees and turn it into soil.
What is the importance of fungi as property damage?
They can cause dry wall, dry rot, wet rot, mold, mildew, etc.
After floods or snow, there can be mildew. Paper in the walls have cellulose and lignin so they are susceptible to fungus.
What is the importance of fungi as mutualists?
- Mycorrhizae: fungi living in close association with almost all plant roots (80 - 90% of all plants)
-Ectomycorrhizae: fungus remains outside of - Endomycorrhizae: fungi penetrate cell wallls and form haustoria (All glomeromycetes are endomycorrhizal)
Mycorrhizal fungi help plants absorb moisture and minerals and the fungus gets sugars from the plant
Lichens: relationship between a fungus and an cyanobacteria. Fungus gives the structure, moisture and minerals. Algae/cyanobacteria gives back sugar.
Soredia can reproduce as a dual organism - a little bit of both
Which group of fungi are ALL endomycorrhizal?
glomeromyctes
What are the key “pioneers” that break down bare rock and live in harsh environments?
Lichens
What is the importance of fungi as pathogens?
- can break down/kill other plants with disease
- Some produce mycotoxins (Ex: ergot - ergotism, LSD)
- infects animals (ascomeycete/cordycepts can create zombie ants, amphibian disease)
-infecting humans:
- mycosis = infection due to fungus
- Ex: “valley fever” - dust storms in the south have fungus living in the dust and can enter our body through respiratory pathways
- Many common ones: ringworm, oral thrush, athlete’s foot, jock itch, vaginal yeast infections
What is the importance of fungi as medicine/research?
- source of antibiotics & other meds
- Ex: penicillin, cephalosporins
- yeasts: can use them to create proteins in-vitro
What is the importance of fungi as food?
- mushrooms
- morels
- truffles - ascomycetes - found underground in roots of trees and they trained pigs to find them
- yeast do fermentation: beer and bread
- Blue cheese: the blue stuff is actually spores in fungi without the fungus it’ll basically just be more like brie
- Soy sauce: fermentation of soy beans using the aspirillus fungus
What is the importance of fungi as poison?
- Moldy foods can kill humans and livestock
- Ex: Ergotism from ergot on rye
- Ex: aflatoxin from aspergillus on corn, peanuts, etc.
What qualities do chlorophytes, charophytes, and plantae share?
What do charophytes share with plantae?
- similar flagellated
Sporopellenin: druable polymer that protects - ## zygotes in charophytes
What does it take to live on land?
- motility
- water balance
- pH condition
- Structure
What was it like for the green algae who moved from water to land?
-more resources, less competition - nobody was there so
- subjected to periodic dehydration
- populations with land adaptation thrive
Advantages:
- more CO2 - no water in the way
- more minerals from the soil instead of just surrounding you in the water
Disadvantages:
- gonna dry out and get crispy without water
- no “support” in air
What classification is horsetails in and describe them?
Horsetails (Equisetum)
- have jointed hollow stems with tiny leaves (the hollow stems have a ton of silica in them)
- this is the plant in the old cartoons where they are underwater with a straw above water to breathe
What classification are ferns in and describe them?