Lecture 20 - Fungi (part 2) & Protists Flashcards
How are fungi key decomposers within the environment?
- they’re saprotrophs
• Break down wood, leaf litter, organic matter is soil
• Really any carbon-containing substrate -> even jet fuel!
• Provides inorganic nutrients essential for plant growth
Saprotrophs
ex: fungi
- sporotrophic fungi that get their nutrition from dead plant material & other non-living organic material
Endophytic
- fungi that associates with plants
- a fungus that lives inside a leaf or other plant part without causing harm to the plant
- a reason fungi can be mutualists
Symbiotic
- an ecological relationship b/t organisms of 2 different species that live together in direct & intimate contact
- we see this in LICHENS
- Symbiotic relationships between an ascomycete (or sometimes a basidiomycete or glomeromycete) fungus and a green alga and/or cyanobacterium
soredia
- in lichens, a small cluster of fungal hyphae with embedded algae
- how fungi reproduces asexually
Mixotrophs
• Mixotrophs, both photosynthetic and heterotrophic
• Have arisen independently in protist lineages
- we see this in protists
plastid
- organelle that does cool things, either photosynthesis or cellular respiration etc. within the cell
- are found in cells of photosynthetic eukaryotes
- we see this in secondary endosymbiosis (photosynthetic eukaryote becomes the new plastid)
nucleomorphs
Residual nuclei (nucleomorphs) are strongest evidence of EST b/c some organisms usually in Rhizaria & the cryptonomads retain these multiple nuclei even though they have their own nucleus themselves • Rhizaria and cryptonomads
pseudopodia
- a cellular extension of amoeboid cells used in moving & feeding
- we see this in the supergroup rhizarians
Phytoplankton
small planktonic things that photosynthesize
• Main cause of shellfish poisoning due to the toxins they produce
• Can result in huge “blooms”
- we see this in the diatoms (in the subgroup Stramenopiles)
accessory pigment
another pigment other than the main photosynthetic pigment
- usually help in either antioxidant properties or allowing the absorption of additional wavelengths of light
- so it’s an accessory pigment, it’s not the primary pigment
- we see this Brown Algae (in the subgroup Stramenopiles)
Holdfasts
anchorage
- a specialized structure in brown algae
Stipe
“stem”
- a specialized structure in brown algae
Blades
“leaves”
- a specialized structure in brown algae
analogous structures
- the specialized structures in the brown algae (ex: holdfasts, stipe, blades) that AROSE independently from similar features in plants
zooplankton
- UNICELLULAR organisms (zooplankton) that MOVE via cilia
- they have to HUNT & EAT stuff in order to get their ENERGY, they don’t photosynthesize
- most are PREDATORS that feed on bacteria & algae
- we see this IN CILIATES (in the subgroup alveolates)
tests
the porous shell of a foram
• Name Foraminiferans (Forams) means “little hole” for their porous shells (tests)
• Made of calcium carbonate
Chlorophytes
mostly freshwater and terrestrial species
• Can be unicellular, multicellular and/or colonial
- we see this in Green Algae (supergroup Archaeplastida)
colonial
- a colony of single-cell organisms is known as colonial organisms
- we see this in Green Algae (supergroup Archaeplastida) specifically in chlorophytes
Charophytes
closely related to land plants
- we see this in Green Algae (supergroup Archaeplastida)
plasmodium (syn. syncytium)
• Form a mass called plasmodium (syn. syncytium), a single-celled cytoplasm containing many nuclei
- the parasitic organism that causes malaria
- we see this in plasmodial slime moulds (within the slime moulds (Mycetozoans) within the clade amoebozoans & in Apicomplexans!
sporozoites
specialized cells that INVADE host cells
- ex: Plasmodium, parasite that causes malaria
- we see this in Apicomplexans (within the subgroup Alveolates)
micronucleus
exchange of genetic material during conjugation
- we see this in the Ciliates (within the subgroup alveolates)
macronucleus
transcriptional active (produces RNA) - we see this in the Ciliates (within the subgroup alveolates)
Describe how Fungi can be mutualists
Endophytic fungi associate with plants
• Not limited to roots (compared to mycorrhizae), found in all plant tissues
• Most are ascomycetes
• Provide a range of beneficial effects including producing anti-herbivory
toxins, increasing heat/drought/heavy metal tolerance
Animal mutualists
• Some occur in the guts of animals (chytrids in sheep)
• Ant colonies farming fungi for nutrients (Leaf cutter ants)
Describe Lichens
- SYMBIOTIC relationships between an ascomycete (or sometimes a basidiomycete or glomeromycete) fungus and a green alga and/or cyanobacterium
- GROW ON various SUBSTRATA: rocks, soil, trees, metal, concrete, plant leaves
- Most are TERRESTRIAL but some are AQUATIC
- ~13,000 species of lichens identified to date
What are the 3 growth forms of Lichens?
- fruticose (shrublike)
- foliose (leaflike)
- crustose (encrusting)
How do Lichens reproduce?
- sexual via fungal life cycle
* asexual via soredia, fragmentation, other specialised structures
Describe Eukaryotes
• Eukaryotes: protists, plants, animals, fungi
• Have membrane-BOUND organelles
• Have a NUCLEUS
• Have a CYTOSKELETON for support (Allows for asymmetrical cell forms)
- most are SINGLE-CELLED organisms