Fungi Flashcards
are fungi multicellular or unicellular, Prokaryotic or eukaryotic
Fungi are mostly multicellular eukaryotes, though there are some unicellular fungi.
how do all fungi feed
All Fungi feed by absorption (chemoheterotrophs)
what are hyphae
In filamentous fungi, the thin strands of cells are called hyphae.
what is a mycelium
The majority of a fungi biomass is a non reproductive region called the mycelium.
what is a fruiting body (Fungi)
The part of the fungi that is usually visible above the ground is called the fruiting body. This is what we call a mushroom. It is the reproductive tissue.
what supports fungal cells
Fungal cells have cell walls and contain chitin for support compared to plant cellulose.
what are the two types of hypha in fungi
- Septate fungi (most fungi) have hypahe divided into cells by septa, with pores that allow cell-to-cell movement of organelles
- Coenocytic fungi lack septa and have a continuous cytoplasmic mass containing hundreds of thousands of nuclei.
what are the 5 fungi phyla
- Chytrids
- Zygomycetes (Zygote fungi)
- Glomeromycetes (arbuscular mycorrhizal fungi)
- Ascomycetes (sac fungi)
- Basidiomycetes (Club fungi)
how are fungi divided
Divided based on cell characteristics and/or spore-producing structures
what are the 4 broad categories of feeding fungi have
All fungi are chemoheterotrophs but have a wide range of feeding habits that fit into 4 broad categories:
- Saprotrophic
- Parasitic
- Predatory
- Mutualistic
where can you find fungi
Fungi are generally confined to aquatic or moist habitats, though some have specialized into arid conditions like deserts
what are Saprotrophic fungi
The majority of fungi are probably saprotrophs and many are closely associated with certain species of plant or animal.
They play a crucial role in decomposition or organic materials and the mycelia of countless species reach deep into soils.
What are Parasitic fungi
Some fungi will attack living hosts, using hyphae adapted to penetrate into living tissue, and some are serious agents of disease for plants and animals
Diseases caused by fungi are often referred to as ‘mycosis’
what are predatory fungi
Some fungi have hyphae adapted for trapping and killing prey
what are mutualistic fungi
Many fungi especially in Glomeromycota have evolved very close associations with plant roots via mycorrhizae.
“Endophyte” is a general term that refers to mutualistic organisms that live in plant roots
what are mycorrhizal fungi
Many fungi are considered mycorrhizal and form close symbiosis with plant roots, many are mutualistic some are parasitic.
what are Ectomychorrizae fungi
- Ectomychorrizae - fungal symbiotes living on the outside of surrounding roots
- Appear in Zygomycetes, Ascomycetes, Basidiomycetes
what are Endomychorrizae fungi
- Endomychorrizae - fungal symbiotes living on the inside of roots.
- Confined to Glomeromycetes
what are arbuscules
Some fungi have specialized hyphae that allow them to penetrate tissues of their host. e.g. arbuscules
what are lichens
A lichen is a symbiotic associtation between a photosynthetic microorganism and a fungus (sometimes more than one fungus)
The symbioses are so complete in lichens that they are given their own species names.
what ploidy do fungi spend most of their life in
For the typical multicellular species, most of the life is spent in the form of the mycelium (i.e. as a haploid
Nuclei are normally haploid with the exception of transient diploid stages formed during the sexual phase of reproduction.
how do fungi reproduce
Fungi can reproduce sexually without ‘sexes’
Two separate cells with different mating time fuse into one cell with two separate nuclei (heterokaryon)
the fused cells can eventually form a zygote with a single nucleus.
What are heterokaryote cells
mainly fungal cells that come from 2 fused cells of different mating types. Have two nuclei, not quite a zygote
what does Karyo refer to
nuclear material and chromosomes
how does sexual reproduction occur in fungi
Sexual reproduction requires fusion of nuclei from different mating types (and usually quickly followed by meiosis)
when did fungi colonize land
Fungi were among the earliest colonizers of land and possibly formed mutualistic relationships with early land plants.
where do fungi come from
They are in the group Opisthokonts along with animals, Chanoflagellates and Nucleariids. Closest to Nucleariids.
Both Nucleariids and Choanoflagellates are flagellated and unicellular, the common ancestor of fungi and animals was likely also unicellular and flagellated. Though in extant fungi the flagella is typically absent and most are multicellular.
how many species of fungi are there
Around 1.5 million species of fungi have been described but there are an estimated 15 million species in the world today.
what are Coenocytic fungi analogous to
Coenocytic fungi with no septum in the hypha are analogous to plasmodial slime molds, and these analogous characteristics led to early confusion about the classification of ‘slime molds’ as fungi.
what is Mycology
Mycology = the biological study of fungi
based on “myco” the greek word for fungus or mushrooms
what is the Humongous fungus
The world largest individual organism is the mycelium of a ‘honey mushroom’ Armillaria ostoyae
The Humongous fungus occupies approximately 9.1 $km^2$ and possibly weighs 35,000 tons
what is Basidiomycetes
includes mushrooms but also many other forms like shelf fungi and puffballs
what is Ascomycetes
includes truffles, morels, and yeasts
make bread, beer, etc
what is Zygomycetes
sometimes referred to as ‘pin molds’ because of the shape of the ‘fruiting bodies’ aka Sporangia
Black bread mold
what is Glomeromycetes
includes mycorrhizal fungi (plant root symbiotic)
Glomeris roughly means ball shaped
has ball shaped spores
what are chytrid fungi
found in moist terrestrial freshwater and marine habitats
Spores have whip-like flagella
Unlike the other fungal phyla, chytrids are characterized by having motile (flagellated) spores
One species is notorious for inflecting amphibians.
what is a basidiocarp
Basidiocarp is the precise name of the fruiting body of basidiomycete fungi.
Some mushrooms are consumed really common.
Ex: White button = Cremini = Portabella = Agaricus bisporus
how do other animals rely on fungi
They are also food or habitat for many other organisms
Although toxicity of some mushrooms species may be the product of natural selection for protective chemicals, some fungus-loving species can tolerate these toxins.
Nonhuman animals like leafcutter ants farm the fungi from leaf cuttings
how have fungi impacted health
Fungi have led to the development of human medicines.
Many fungi have evolved biochemical ‘weapons’ that have been indispensable for human medicine.
Ex: Penicillin was made from Penicillium a mold.
what is Cordyceps
One unique group of parasitic fungi are Cordyceps, which zombify ants by infecting them with spores, then causes it to climb to the stem or underside of a leaf before latching on and dying. The fungus grows and consumes the ant, then grows a stem called a stroma from the ants head, and releases spores into a killing zone which infect new ants.
do fungi parasitis other fungi
Some fungi parasitize other fungi. Life Hypomyces Lactifluoru infects Russula brevipes and turns it into the lobster mushroom.
what is interesting about oyster mushrooms
The oyster mushroom, Pleurotus ostreatus is partly carnivorous and uses poison to kill small invertebrates.
how is kombucha produced
Kombucha is a drink resulting from fermentation by a: Symbiotic culture of Bacteria and Yeast
what are the 4 components of a fungal lifestyle
- Zygote (fusion of gametes)
- Meiosis (recombination)
- Haploid phase
- Heterokaryotic phase
describe the lifecycle of a Basidiomycetes fungi
Basidiospores (n) dispers and germinate.
They make haploid mycelia of mating types + or -.
When they find another mycelia of opposite type they undergo plasmogamy to form a Dikaryotic Mycelium.
This then grows a Basidiocarp (n+n) that has gills lined with basidia.
In the basidia (n+n) Karyogamy occurs creating a diploid phase.
then very quick meiosis occurs creating diploid nuclei.
Each Basidium contains four haploid nuclei which are made into four basidiospore, which are released.
describe the lifecycle of a Ascomycete fungi
Spores (n) disperse and germinate in the spring.
They produce mycelia of mating types + or -.
The - mating type creates a conidiophore which asexually reproduces and releases conidiums (like spores), which either make more type - mycelia,
or come in contact with a type + mycelia.
From the Conidium and Mycelium plasmogamy occurs creating the heterokaryotic hyphae.
On the Heterokaryotic hyphae an ascus forms: a sac shaped structure.
In the ascus the nuclei fuse and diploid nuclei exist.
Then meiosis occurs resulting in four haploid nuclei in the ascus.
They then create 8 ascospores.
The ascus then creates a large structure called an Ascocarp, which contains asci, which contain spores which are released.
describe the lifecycle of a Zygomycete
Spores disperse and germinate.
They create mating types + or - mycelia
Some might undergo Asexual reproduction releasing spores.
When a mating type + and - mycelia connect they make a Gametangia with haploid nuclei.
The Gametangia undergoes Plasmogamy to form a Zygosporangium where heterokrayotic cells exist.
It grows and then undergoes Karyogamy to make a diploid nuclei, which undergoes meiosis.
The Zygosporangium produces a sporangium which releases spores
