What are some examples of algae?
- Brown algae
- Golden algae
What are red algae also known as?
Where are red algae found?
Mostly marine, but some freshwater and terrestrial
Where does color of red algae come from?
- Phycoerythrin - an accessory pigment
- It is produced by cells
What is the one unicellular species of red algae?
Galdieria - lives in acidic hot springs
What are green algae also known as?
What are chlorophytes closely related to?
Where are green algae found?
Most inhabit freshwater but some are marine or terrestrial
How do chlorophytes reproduce?
Both sexual and asexual
Where do endolithic algae grow?
Inside porous rocks
How many cells do chlorophytes have?
Can be unicellular to multicellular
Most fungi have how many cells?
What is a mycelium?
- Vegetative part of a fungus
- Consists of a network of fine white filaments (hyphae)
What does coenocytic mean?
Cytoplasm and nuclei are not subdivided into cells
What does septate mean?
Nuclei are separated by cross wall
What are conidia?
- Hyphae that extend above the surface can produce asexual spores called conidia
- They are often pigmented and resistant to drying
Most fungal cell walls are made of what?
How do fungi feed?
- Feed by secreting extracellular enzymes that digest complex organic materials (polymers)
- Monomers, or short polymers are then assimilated
What is mycorrhizae?
- Symbiotic association where some species of fungi form close relationships with plant roots
- Example: glomeromycetes
- Help plant roots obtain phosphorous
- Fungi obtain nutrients from the plant
What do ectomycorrhizae do?
Form a sheath around the plant root but does not penetrate it
What do endomycorrhizae do?
The fungal hyphae is embedded in the plant root
Can fungi cause disease?
- Yes, in plants and animals
- Example: dutch elm trees were devastated by fungal infection of the ascomycete Ophiostoma ulmi
What are haustoria?
The specialized hyphae that many fungal plant pathogens form
What are mycoses?
- Fungal infections in animals
- In humans range in severity from athlete's foot to histoplasmosis
- Immunosuppression is a major risk factor
How do most fungi reproduce?
- Asexual means, 3 forms:
- 1. Growth and spread of hyphal filaments
- 2. Asexual production of spores
- 3. Simple cell division (budding yeasts)
How do fungi reproduce sexually?
- Some fungi produce spores
- Sexual spores can originate from the fusion of 2 haploid cells to form a diploid cell (ascospores, basidiospores, zygospores)
- Spores are resistant to drying, heating, freezing, chemicals
Fungi share more common ancestor with ______ than any other group of eukaryotic organisms
When is it estimated that fungi and animals diverged?
1.5 billion years ago
What is the earliest fungal lineage known?
Thought to be chytridiomycetes?
What are chytrids?
- earliest diverging line of fungi
Where are chytrids found?
Commonly found in moist soil and freshwater
How many cells do chytrids have?
Some unicellular some colonial
What does the fruiting body of chytrids contain?
- Sexual spores called zoospores that are flagellated and motile
- Beneficial for dispersal
What are some chytrids implicated in?
- Massive die-off of amphinians
- Some are pathogenic
What are zygomycetes known for?
Primarily for food spoilage
Where are zygomycetes commonly found?
In soil and decaying plant material
What is Rhizopus stolonifer?
- A black bread mold
- A representative of zygomycetes
What are ascomycetes?
Highly diverse, single-celled species (baker's yeast) and multicellular species
Where are ascomycetes found?
Found in aquatic and terrestrial environments
What do ascomycetes do?
- Decompose dead plant material
- Some are lichen symbiots
How do ascomycetes reproduce?
Sexual reproduction - 2 haploid nuclei from different mating type fuse, forming a diploid nucleus that undergoes meiosis to form haploid spores located in a sac (ascus)
What is an ascus?
The sexual spore-bearing cell produced in ascomycete fungi
What shape are the cells of Saccharomyces cerevisiae?
Spherical to oval
How do Saccharomyces cerevisiae undergo cell division?
How do Saccharomyces cerevisiae reproduce?
Sexual reproduction, mating types
What is Saccharomyces cerevisiae a species of?
What kinds of cells can switch from one type to another by genetic switch mechanism?
How many described species of Basidiomycetes exist?
Most Basidiomycetes are recognizable as what?
Mushrooms and 'toadstools'
Are Basidiomycetes edible?
Some are edible, some are highly poisonous (like Aminita)
Basidiomycetes are also _____ and ________ of plants and humans
yeasts and pathogens
How do Basidiomycetes reproduce?
- Undergo both vegetative and sexual reproduction
- Spores are at the end of a club-shaped basidium