fungi and invertebrates Flashcards
describe fungi
are one of the oldest and largest monophyletic kingdoms.
-ancestor resembled unicellular, flagellated choanoflagellates.
-were one of the first organisms to exploit land.
created a suitable environment for the evolution of plants. How?
also phloem tissue of plants. doesn’t need to search for food, but most fungus do
are more closely related to animals than plants. How?
Animal fungi plants
heterotroph Heterotrophs (decomposes) photoautotroph
Glycogen (food stores) Glycogen (food stores) Starch (food stores)
Exoskeleton: chitin (insects, crustaceans Cell wall: chitin Cell wall: cellulose
fungi are mainly multicellular eukaryotes. Exception?
yeast is a unicellular fungus. were once multicellular, but became unicellular because of where they are found. found in areas with lots of nutrients. find on fruit, vaginal tracts, fermenting fruits
what are fungi made of?
the structure
Fungi are composed of thin, cylindrical structures
called hyphae.
cell wall of fungi vs cell wall of bacteria
have protective cell walls made of a nitrogen containing polysaccharides called chitin.
bacteria have cell walls made of peptidoglycan
Bacteria cell walls vs chitin in fungal cell walls. Hydrogen bonds between chitin, easeir to break down. Peptidoglycan hard to break because of covalent bonds
what is the undeground structure of fungi called and why does it grow the way it does?
Mycelium grows a lot to decompose dead matter and get food. It decomposes dead leaves and rats. Mycelium has a large surface area, so it can produce more enzymes. These enzymes use food to externally digest. This releases nutrients, which the mycelium then absorbs. Fungus is underground and very extensive.
why are the reproductive structures of fungi temporary?
because they tend to sprout in favourable conditions (after rain there is lots)
what is coenocytic hyphae?
“continuous” cytoplasmic mass. No separation btw the hyphae. Does mitosis. Lacks cytokinesis so cells don’t separate from each other. Allows for easier transport. Easier growth. Faster growth. Makes it a more efficient hunter. Saves energy by not making cross walls, all that energy goes into growth instead
-the issue is that most of the nucleuses could end up at the tip, not a lot in the rest, not good
septate hyphae. Why are they more advanced
there is separation that happens between the nuclei. Has wholes where nutrients can still go across. Only stops nucleus from groing through cross-walls. The advantage of cross walls is that they can cut off part if a portion of it is infected. Bacteria is limited to how much it can affect fungus.
If there is a cut in the cross wall, limits the amount of damage in the other one, no way of cutting off cyoplasmic flow.
-crosswalls make it less likeley to collapse. when it’s being stepped on
-nucleus equally spaced apart
how are fungi classfied?
They all have mycota in the name
which fungi are the most advanced. Why?
Basidiomycota and Ascomycota because of their multicellular sexual reproductive structures
are septate hyphae analogous or homologous
homologous because on tree (slide 3) found in common ancestor
are basidiocarps and ascocarps analogous or homologous?Why?
analogous because evolved independently due to convergent evolution
describe Zygomycota and give an example?
develop coenocytic hyphae
an example is Rhizopus (black bread mold)
Choose sexual reproduction in unfavourable environment, this makes offspring genetically diverse and some of them survive
how do Zygomycota sexually reproduce
the tips of negtive and positive mating types. (attract each other via pheromones) swell up when they meet. This is calles plasmogamy which meand “cytoplasm” together
Then creat protective wall.
They reproduce via zygosporangium (which is dormant until in a favourable nevironment)
plasmogamy vs karyogamy in zygomycota
plasmogamy is the fusion of two parent fungi that brings 2 nuclei together, but doesn’t fuse (n+n)
karyogamy is the fusion of the two haploid nuclei in the cell that resulted from plasmogamy. This forms a diploid nucleus, which contains two sets of chromosomes, one from each parent.
what are the 3 stages of sexual reproduction in fungi
- Plasmogamy: The fusion of the protoplasts
- Karyogamy: The fusion of the nuclei
- Meiosis: The division of the diploid nucleus to reduce the chromosome number to one set per cell
what are asci, ascocarps and ascospores? (Ascomycota)
Asci: These are specialized sac-like structures where meiosis occurs. They are formed during the sexual reproduction phase of ascomycete fungi. Each ascus typically contains eight ascospores, although the number can vary in some species.
Ascocarps: These are the fruiting bodies, where asci are produced. The structure of the ascocarp can influence how spores are released into the environment.
Ascospores: These are the spores produced within the asci. After the asci mature, they release the ascospores, which can then germinate to form new fungal individuals. The release of ascospores often occurs when the asci burst or when the ascocarp is disturbed.
describe life cycle of ascomycota
1.Plasmogamy: The process begins when two compatible fungal hyphae fuse, leading to the formation of a dikaryotic mycelium (with two nuclei).
2.Karyogamy: The nuclei eventually fuse to form a diploid nucleus.
3.Meiosis: This diploid nucleus undergoes meiosis, producing four haploid nuclei.
4.Mitosis: Each haploid nucleus may then undergo mitotic division, resulting in a total of eight nuclei.
5.Formation of Asci: The eight nuclei are enclosed within the asci, and the asci are developed within the ascocarp.
6.Release of Ascospores: Once mature, the asci release the ascospores into the environment, where they can disperse and germinate under suitable conditions.
what phylum is orange peel cup fungus in and morel in?
ascomycota
what phylum are truffle and yeast in?
ascomycota
true or false basidomycota reproduce asexually
false, they don’t do that
what are basidia, basidiocarp and basidiospores?
Basidia are specialized club-shaped structures where sexual reproduction occurs. Each basidium typically produces four basidiospores. They are formed on the surface of the basidiocarp.
basidiocarps are the fruiting bodies of basidiomycete fungi. They can take various forms, such as mushrooms, puffballs, or bracket fungi. The basidiocarp contains the basidia and is responsible for producing and releasing basidiospores.
Basidiospores are the spores produced by basidia. After maturation, they are released into the environment and can germinate to form new mycelium.
describe the lifecycle of Basidiomycota
- Plasmogamy: The process starts with the fusion of two compatible haploid hyphae from different mating types. This fusion leads to the formation of a dikaryotic mycelium (with two distinct nuclei).
- Karyogamy: In the basidia, the two nuclei from the dikaryotic mycelium eventually fuse, resulting in a diploid nucleus.
- Meiosis: The diploid nucleus undergoes meiosis, producing four haploid nuclei.
- Formation of Basidia: Each haploid nucleus migrates into a developing basidium, where it becomes enclosed, leading to the formation of four basidiospores.
- Maturation and Release of Basidiospores: The basidiospores mature and are released from the basidia, typically through a process that involves the swelling and elongation of structures called sterigmata that connect the basidiospores to the basidia.
6.Dispersal and Germination: Once released, the basidiospores can disperse into the environment and, under favorable conditions, germinate to form new hyphae and begin the life cycle anew.
what phyla are shelf fungus and netted stinkhorn fungus in?
basidiomycota
what phyla are birds nest fungi and puffballs in?
basidiomycota
what is ergots
purple ascomycete structures that infect rye.
these can make people very sick when flour is made out of them because the fungus produces a toxin. Get psychosis like symptoms, hallucinogenic
mild version given to reduce excessive bleeding during childbirth. LSD
Ringworm and athletes’ foot. Why is it difficult to treat?
caused by ascomycota that feed on dead cells and perspiration. Happens when not washing feet properly in public spaces
ingworm is hard to get rid of because on the surface of the skin. Outer layers of skin, don’t get oxygen and nutrients from blood vessels, so your immune system can’t get to it. Fungi are eakaryotes and so are we. So we get major side effects when taking medications.
what are cordyceps
Sporangia produces, spores are released. Chances chemical structure of brain. Climb to highest place possible, cling onto branch and then the spores spread from there. They kill the ant that is a zombie.
Cordyceps erupt from body. Protect diversity so that no insects overtake any other organism.
give 3 reasons why fungi are ecologically important.
Are the main decomposers on land because bacteria just wait for food, while fungi hunt decomposing materials
- form symbiotic relationships with plant roots called mycorrhizal. Arbuscules: tree-like network of hyphae. Coenocytic hyphae
Plasma membrane is intact, so can continuously absorb nutrients from plant cell without killing it. Fungus gives sugar and oxygen. Not parasitic because fungues delivers minerals from far distances and supplies plant with potassium, nitrogen, phosphate. Gets things from super far. Mutualistic symbiotic relationship
90% of plants have this symbiotic relationship. Without it, plants do pretty poorly. All plants in given area connected via mycelium. Also allows plants to communicate. Like wifi or internet. Plants can also poison each other through fungi.
- From symbitoic relationships with either algae or cyanobacteria. Called lichens (combination of fungus and either algae or cyanobacteria)
Algae produces sugar and oxy to give to fungus, fungus protects it (liitle house)
Cyanobacteria also does nitrogen fixation to turn into ammonia or Nitrates. (NH3, NO3) fungus uses nitrogen and ommonia to make chitin
what kind of drugs do fungi produce
peptidoglycan. Enzyme turned off, so cell wall of bacteria become very weak. Wall protects against too much water going into the cell. When cell wall is weak, water enters and pops the cells (bursts)
Cyclosporine. Used to prevent your body rejecting an organ. Does this by reducing your immune system until organ is accepted
Fumagilin is used against cancer cells. Prevents the spread of cancer cells. Prevents metastasis (the spreading of cancer cells). Reduces spread from one part of body to antoher. Reduces blood vessel formation and therefore prevents the spread of cancer cells
