BIOL2712 Study Guide - Final Guide: Microbial Cyst, Plasmodium, Lobopodia
25 Jun 2018
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Protozoa
What is it?
Unicellular organisms
Eukaryotic
oCells contain a membrane-bound nucleus or nuclei
Lacking tissue level of organization
Lack cell wall
Intracellular specialization
oAll life functions carried out by organelles within eukaryotic cell
Boundary between autotrophy and heterotrophy blurred
Small
o< 0.5 um – 3mm
Play important roles in all ecosystems
oAs primary producers or for nutrient cycling
oImportant part of food webs
Parasitic forms cause health problems
oInvertebrates
Inc. commercially important bivalves or prawns
oVertebrates
Inc. fish and humans
Direct or indirect infestation
Evolutionary stepping stone to the metazoa
250,000 species
10,000 species are symbiotic (mutually beneficial relationship b/w organisms)
oMutualistic
Both organisms require the other to survive
oCommensalistic
One organism benefits from the other organism without affecting it
oParasitic
One organism derives nutrients and resources from another
organism, harming it in the process
14 phyla
Difference between protozoa and metazoan
oProtozoa
Single celled
One cell performs all actions, therefore there is no division of labour
Cellular grade of organization – e.g. Amoeba, paramecium
oMetazoa
Multi-cellular
Different cells perform different functions
Have cellular tissue, organ and system grade of organization – e.g.
sponges to chordates
find more resources at oneclass.com
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Evolution of eukaryotes by endosymbiosis
Process where one prokaryote lives inside another becoming dependent upon each
other
oOrigin of eukaryotes
Modes of Motility
Mechanism Group (traditional taxa
groupings)
Pseudopodial movement Amoebas
Flagella Flagellates
Cilia Ciliates
Gliding motility Sporonzoa (parasitic)
Locomotory Organelles
Cilia
oPropel water parallel to surface which cilia are attached
oOar-like motion
o10-20 um
Flagella
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find more resources at oneclass.com
oPropel water parallel to main axis of flagellum
oWhip-like motion
o20-200 um
Axoneme
oComposed of 9+2 microtubules
Lobopodia
oLarger, blunt extensions of cell body
oColloidal ecto- and fluid endoplasm
Filipodia
oThin extensions, branching, contain on ectoplasm
Reticulopodia
oForm netlike mesh
Axopodia
oLong, thin pseudopodia supported by axial rods of microtubule
Pseudopodia
oExtensions of cytoplasm
Nutrition
Autotrophic
oOrganisms producing their own energy resources from inorganic raw
material, by photosynthesis
Heterotrophic
oOrganisms require an external source of food, ingest organic nutrients and
material in the form of other organisms
Saprobic (osmotroph)
oAbsorption of dissolved organics, ingest food in soluble form
Holozoic (phagotroph)
oIngestion of solid organic food particles
Phagocytosis
oInvagination of cell membrane around food particle, enclosed in food
vacuole, enzymatic digestion (lyzosomes)
Feeding in Protozoa (all technically phagocytosis)
Amoeba
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Eukaryotic: cells contain a membrane-bound nucleus or nuclei. Intracellular specialization: all life functions carried out by organelles within eukaryotic cell. Play important roles in all ecosystems: as primary producers or for nutrient cycling, important part of food webs. Inc. commercially important bivalves or prawns: vertebrates. 10,000 species are symbiotic (mutually beneficial relationship b/w organisms: mutualistic. Both organisms require the other to survive: commensalistic. One organism benefits from the other organism without affecting it: parasitic. One organism derives nutrients and resources from another organism, harming it in the process. One cell performs all actions, therefore there is no division of labour. Cellular grade of organization e. g. amoeba, paramecium: metazoa. Have cellular tissue, organ and system grade of organization e. g. sponges to chordates. Process where one prokaryote lives inside another becoming dependent upon each other: origin of eukaryotes. Cilia: propel water parallel to surface which cilia are attached, oar-like motion, 10-20 um.
