Feb. 20th (Exam 2) Flashcards
What are the economic concerns surrounding fungi?
- yeasts
- food
- crop diseases
- human diseases
- fermentation
What are the ecological concerns regarding fungi?
- interaction with other organisms
- decomposition
- succession (change in species composition within a community)
Regarding fungi:
How do they get nutrients?
Cell wall structure?
Storage carbohydrate?
- They are heterotrophic
- They have cell walls composed of chitin fibrils
- Glycogen (oftentimes)
Regarding fungi:
What features are plant like?
What features are animal like?
Plant like:
- Sessile
- Rigid cell wall
- Growth from spores (some early plants)
- Have branching filaments (hyphae) that are somewhat like roots
Animal like:
- Heterotrophic
- Glycogen storage
- Chitin in cell walls are analogous to exoskeletons of arthropods
- Use digestive enzymes
What eukaryotic supergroup are animals in?
What is the subgroup that both animals and fungi belong to?
- Unikonts
- Opisthokonta`
Describe the general structure of fungi.
They can be made of single cells (like yeasts) or as multicellular filaments.
The multicellular filaments are called hyphae
What are a bunch of hyphae called?
Mycelium
Define hyphae.
These are the threadlike structures that make up the body of the multicellular fungi.
Define mycelium.
This is the network of hyphae that form the main body of the fungus.
What is the difference between septate and nonseptate hyphae?
- Septate - have walls called septa that separate the hyphae into sections, each with its own nucleus
- Nonseptate - there are no walls between sections, so hyphae are long continuous and have many nuclei
Describe fungi reproduction.
Can be asexual or sexual by producing spores in one way or another - 100k spores per cubic meter!
Describe sexual reproduction of fungi:
What is plasmogamy?
What is a dikaryon?
What is karyogamy?
Plasmogamy is the fusion of cytoplasm of two fungi.
Dikaryon is the idea of two separate genetically distinct nuclei in one cell that follows plasmogamy.
Karyogamy is the fusion of the nuclei of the the two fungal cells after plasmogamy (results in a diploid nucleus
Describe asexual spore formation.
Can be produced within a sporangium (enclosed)
Can be produced within a conidia (without enclosure)
What are the fungi like protists that we talked about?
What are they actually more closely related to?
- Slime molds - amoeba
- Water molds - diatoms/brown algae
What are Chitridiomycota?
Type of fungi that are typically parasites of plants animals and other fungi.
Why have Chitridiomycota been associated with the world-wide amphibian decline?
They infect the dermal cells of amphibians and cause respiratory issues, as this is how some respirate.
What was the basis for the naming of Zygomycota?
They have thick-walled zygosporangium (sexual reproduction)
What type of hyphae do the zygomycota have typically?
What is an example of zygomycota?
nonseptate
The rhizopus stolonifer bread mold
What is the basis for the naming of ascomycota?
Asci means “sac” i.e “sack fungi”
Do ascomycota have septate or nonseptate hyphae?
They have septate hyphae
What is the ascocarp?
What is it made of?
This is the fruiting body of the ascomycota where spores are formed and released
Separate dikaryons
Describe the sexual reproduction of ascomycota.
- Karyogamy
- Then meiosis (spores)
- Then mitosis
Creates 8 spores
What are four examples of ascomycota?
- Morelles
- Truffles
- Brewers/ Bakers yeast
- Thrush (female)
- Athletes foot
Why does ascomycota include “imperfect fungi”
like what does this mean?
It means that they don’t have a known sexual stage, but their DNA is still linked to ascomycota.
What are the three examples of imperfect fungi that belong to ascomycota?
- Penicillium
- Aspergillus
- Geomyces destructans
Describe penicilllium
This is the source of the antibiotic penicillin - also a component of cheese
Describe aspergillus
This can cause a lung infection - you know it.
Found in compost heaps
Describe the geomyces destructans
Causes white nose syndrome in the insect eating bats - kills all of them nearly
What is the basis for the naming of the fungi Basidiomycota?
Their spores are produced on basidium - club like or peg like “club like fungi”
What is the sporulating body called and what is it made of?
It is called the basidiocarp and it is made of separate dikaryon (septate)
Explain the sexual reproduction of the basidiomycota.
AKA how are the basidiospores made?
Karyogamy and then meiosis occur within the basidium to make them.
What are examples of basidiomycota?
- Most mushrooms
- Puffballs
- Plant pathogens like rusts and smuts
What are the various ecological roles of fungi?
- Parasitic - like rusts/smuts and also chitridiomycota and some ascomycota
- Mutualistic symbiont (benefit host) - mycorrhizal fungi
- Saprobe - nutrients from non-living stuff (mushrooms/puffballs)
What is the idea of mycorrhizae?
What do plants get?
What do fungi get?
This is the symbiotic relationship between plant roots and fungi.
Fungi aid the plant in absorption of mineral nutrient and water by increasing surface area of roots, plant aids fungi by giving substrate to live on and giving it sugars and amino acids.
What are the two types of mycorrhizae?
Ecto - form mantle around the root
e.g mostly basidiomycetes
Endo - hyphae penetrate the plant cell walls
What are the two structures (endo/ecto) that help the plant absorb nutrients?
Ecto - Hartig nets
endo - Arbuscle
What are lichens?
This is a symbiotic relationship between fungi and cyanobacteria or green algae.
Who benefits more typically?
Fungi, most algae can exist on their own
What is very unique about lichens?
Because of their symbiotic relationship, they can survive extreme conditions that they might not otherwise be able to.
What type of “fungi” caused the Late Blight of the Potato
Water mold which belongs to oomycota
What are the characteristics of the Rusts (plant disease causing fungi)?
Where are they common to?
Most of them require two hosts to complete their life cycle.
Cereal grains
Talk about the requirements of the fungus “Cedar rust fungus” and its life cycle.
- Requires the juniper (cedar) to overwinter surviving the harsh conditions
- When conditions are right, they infect the apple tree where they can actually sexual recombine and then infect the juniper again.
*leaves and fruit of apple
What are other diseases that we talked about?
- Corn smut (one host) delicacy
- Dutch elm (beetles then elm)
- Sudden oak
What approaches can be used to control fungal diseases without the widespread use of fungicides?
The most important methods for controlling fungal diseases without fungicides are using resistant plant varieties and practicing crop rotation. These approaches disrupt the pathogen’s life cycle and make plants more resilient to infections.
