BIOL10005 Lecture Notes - Lecture 19: Saprotrophic Nutrition, Cyanobacteria, Lignin
29 Jun 2018
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LECTURE 19 - Protist: consumers and absorbers
Colourless protist
Ciliates:
oUnicellular, diverse and complex
Form distinct colonies
oCovered with flagella called cilia
o2 types of nuclei: micronucleus and macronucleus
Micro: backs up copy of genes
Macro: copy that does all cell operation
oPredatory - feed on other things (bacteria, protists, other ciliates)
Sexual cycle: Eukaryotes have sex while prokaryotes doesn’t
oWhen two ciliate mate: exchange of micronucleus
After separation: macronucleus degenerates
Micronucleus make new macronucleus
Sexual cycle: start with two cells --> end with two cells
Reproduction = exchange of genes, diversity
oBacteria has transformation
Repairs DNA
oMeiosis: aids in DNA repair
oEvolution of meiosis = the repair of DNA
oAll multicellular, even humans --> start new generation with cleaned up template of
DNA
Amoebae:
Eukaryote lineage
Do not form single lineage
Pathogens --> engulfs prey by phagocytosis
Other: choanoflagellates, non/cellular slime moulds (close to fungi) --> absorbers, recyclers, some
predators
CHOANOFLAGELLATES (‘collar’ flagellates or sponge-like protists)
Aquatic habitats
Tiny, unicellular protists closely related to the choanocytes of sponges
At the base of the phylogenetic tree that gave rise to the animals
Heterotrophic consumers
SLIME MOULDS – AMOEBOID PROTISTS (dictyostelids)
Heterotrophs – absorb or engulf food after external digestion (like fungi)
Major decomposers and recyclers
Reproduce by spores in fruiting bodies called sorocarps
Cellular slime moulds (Dictyostelids) – feed on bacteria and decaying organics
oSocial life cycle --> goes from single to a group
oEvolution of cell to cell communication
oDoes multicellular cells come from this?
Acellular slime moulds (Myxomycetes) – decomposers
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Document Summary
Predatory - feed on other things (bacteria, protists, other ciliates) o o o. Sexual cycle: eukaryotes have sex while prokaryotes doesn"t: when two ciliate mate: exchange of micronucleus. Sexual cycle: start with two cells --> end with two cells. Repairs dna: meiosis: aids in dna repair o. Evolution of meiosis = the repair of dna: all multicellular, even humans --> start new generation with cleaned up template of. Other: choanoflagellates, non/cellular slime moulds (close to fungi) --> absorbers, recyclers, some predators. Tiny, unicellular protists closely related to the choanocytes of sponges. At the base of the phylogenetic tree that gave rise to the animals. Heterotrophs absorb or engulf food after external digestion (like fungi) Reproduce by spores in fruiting bodies called sorocarps. Cellular slime moulds (dictyostelids) feed on bacteria and decaying organics o o. Social life cycle --> goes from single to a group. Most closely related to animals b/c has cell wall (chitin --> glucose)
