Plants: Lecture 7 Flashcards
Examples of fungi?
- Bread yeast
- Pizza crust yeast
- mushrooms
- Athlete’s foot
- Ringworm
- Black bread mold
- Beer and wine yeast
Characteristics of fungi?
- Heterotrophs (don’t make their own food)
- Eukaryotic
- Main body is haploid
- Can be multicellular or unicellular (yeast is unicellular)
- Cell wall made of chitin (Polysaccharide that makes up arthropod shells, squid beaks and fish scales)
- External digestion of food
- ~120,000 species have been described
What are Hyphae?
Extensions that form a network called a mycelium.
2 kinds of hyphae?
Septate: have divisions between different areas. contains a pores that allow certain items through
Coenocytic: No septums controlling flow and no division whatsoever.
Examples of specialized hyphae?
Predators: makes a noose/snare to trap worms and kill them
Haustoria: go through cell walls and have a symbiotic relationship typically
How do fungi grow?
they digest material outside of their body then bring it inside.
Generalized life cycle?
Typically asexual reproduction
- spores produced with protective coat then germinate (out of coat)
Sometimes go off to sexual reproduction
- Plasmogamy ( 2 cytoplasms with 2 haploid nuclei fuse) creating the heterokaryotic stage with 1n + 1n
- Karyogamy (“fertilization” where nuclei fuse to form 1 diploid)
- Undergoes meiosis to make spores
Spores in fungi?
- Haploid (1n)
- Most are less than 20 micrometers and rarely more than 100
- Each contains a nucleus, dehydrated cytoplasm and a protective coat.
- Can remain dormant for long periods to wait out environment for years sometimes
- Produced by mitosis or meiosis
Purpose of spores in fungi?
- Move to new food source
- Avoid or wait out adverse environment
- Create new genetic combinations by combining 2 genomes
Zygotic Meiosis?
- No sexes beacause no big and small.
- instead we use + or - cells
Types of asexual reproduction in fungi?
- Spores in sporangia
- Conidia spores in conidiophores
- Budding
Fungi are closely related to/
Fungi are closely related to animals
What are the 5 phyla of fungi?
- Chytrids
- Zygomycetes
- Glomeronycetes
- Ascomycetes
- Basidiomycetes
Phylum Chytridiomycota (Chytrids)?
- 1000 species
- single cells or colonies wit hyphae
- Flagellated spore (“zoospore”) that is haploid and asexually produced, swims to move.
- Live in moist environments: aquatic or soil
- Decomposers, parasites, commenals (digestive tract of sheep and cattle)
Spore release in a Chytrid?
It has converted the entire contents of its body into flagellated asexual zoospores.
- Releases these copies as spores for further spread
Amphibian decline?
There has been a massive decline in populations of amphibians and one major cause is due to chytrids that infect the skin.
Phylum Zygomycota (Zygomycetes)?
- 1000 species
- Coenocytic (non-septate) hyphae
- Decomposers, parasites, commensals (live symbiotically)
Entomophthora (insect destroyed)?
Spore infects the animal and the fungus grows, controls the mind of the insect, summiting and head glued down. Consumes the body of the insect and death occurs at dusk.
Pilobolus?
When fluid filled item gets hot enough, it explodes and send the spores flying. They then land on food that cows eat and then they get to their food source.
Black bread mold?
Asexual spores are what we see but there is a large group below.
Zygomycota life cycle?
+ and - unite and forms a diploid nuclei that undergoes meiosis. One huge nuclei
Phylum Glomeromycota (Glomeromycetes)?
- 160 species
- Non-septate hyphae
-Only asexual - Mostly associated with plants
- Obligte symbionts called mycorrhizae which get into the roots and expand to absorb water and minerals. Get in cell walls and grow projections
Phylum Basidiomycota (Basidiomycetes)?
- 30,000 species
- Mushrooms
- Decomposers and ectomycorrhizal
- Long-lived eukaryotic mycelium
- Multicellular
- Septate mycelia
- Multicellular sexual reproduction (fruiting body “basidiocarp” called mushrooms puffballs or brackets)
- Multicellular asexual reproduction: conidia formed by hyphae
Bracket (shelf) fungi?
In dying or dead trees, digest material inside the wood
Puffballs?
Basically a huge mushroom with spores all through the inside.
- When you step on it you release the spores
Stinkhorns?
Smell really bad, eat spores and take away to distribute farther. the net structure is there to distribute the cell farther.
Mushrooms?
Can vary is danger and poison levels
Shiitake is okay
Amanita is BAD
Fairy ring?
Likely when wood is below, mushrooms form a ring
- it comes back with larger diameter the next year
Spores on gills?
Gills are where spores are made by meiosis. This is a “pedestal” structure with 4 legs
Life cycle?
Same as typical but when diploid (karyogamy cells) undergo meiosis and therefore 4 cells remain!
Phylum Ascomycota (Ascomycetes)?
- Sac fungi
- 65,000 species
- Multicellular or unicellular (yeast)
- Multicellular sexual reproduction (fruiting body is an “ascocarp” and consists of cup fungi, morels, or truffles)
Truffles?
Ectomycorrhizae with trees
- type of ascomycota
Blue cheeses?
Made with the spores of ascomycete fungi.
Penicillium?
Source of penicillin.
- Isolation by Fleming in 1928 and clinical treatment in 1941
Asexual reproduction in Ascomycota?
Unicellular - budding
Multicellular - Formation of conidia spores on conidiophores.
Asci?
There are 8 spores in each ascus: undergo meiosis and then mitosis.
8 cells = ascus
Formation of ascospores?
+ and - join in plasmogamy then undergo fusions, meiosis, then mitosis. 8 cells at the end!
Ergot alkaloids?
- Grow on rye mainly
- Several kinds
- St. Anthony’s fire (extreme heat on extemeties)
- Restrict blood flow causing gangrenous ergotism
- Salem witch trials
- Medicinal uses
- LSD is a derivative of it
- LSD synthesized by Albert Hoffmann in 1938, ingested it and went on a bike ride
Botrytis?
Rots fruits
Yeast?
- Budding
- Brewer’s
- Bakers
makes bread, wine, beer, etc.
Aspergillus fumigateurs?
Inhabitats soils worldwide
- Wide thermal tolerance
- Conidia exposure contacts and unavoidable
-We inhale more than 100 a day - 1-100 conidia/m^3 in air
- Spores are small and can reach respiratory pathways
- Normally cleared
- Invasive versions cause disease in immunocompromised people
- Difficult to treat
Candida albicans?
- Normal part of human gut flora
- Also on skin and in oral cavity, urogenital tract
- Transmitted from mother to child during childbirth
- 2 morphological forms: yeast and hyphal
