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Flashcards in Microeukaryotes Deck (29):
0

Characteristics - 7

Endomembrane system
Cytoskeleton
Nucleus
Mitochondria
Multiple linear chromosomes
Sexual reproduction (haploid and diploid generations)
Flagella

1

Cytoskeleton

Microtubules
Microfilaments
Cortical actin skeleton

2

Microfilaments

twisted cables of actin

3

Microtubules

hollow rods of tubulin
Arise from microtubule organising centres or basal bodies of flagella

4

Cortical actin skeleton

Underlies cell membrane
Allows change of shape: phagocytosis, pseudopodia
Stress fibres protect cell from environmental stresses

5

Size

Mostly 5-20 micrometers
Amoeba more than a few cm
Pico-eukaryotes: 1 micrometer

6

Similarities

Actin -> MreB (cell elongation)
-> ParA (plasmid and chromosome segregation)
Tubulin -> FtsZ (z-ring)
Glycolysis, TCA cycle -> bacteria
Ribosomes, RNA polymerases (info transfer)-> archaea

7

TCA

Citric acid cycle
Krebs cycle

8

Mitochondria - 6

Cristae, matrix
Bacteria-sized
Circular chromosomes
Bacterial (70S) ribosomes
Mitochondrial DNA similar to rickettsias

9

Rickettsias -6

Parasitic bacteria
Typhus, chlamydia
Reproduce only inside host
Energy parasites
Outer membrane of mitochondrium would be hosts vacuole, inner would be rickettsias outer membrane)

10

Micro eukaryotes naming

Protists - all
Protozoa - only non-photosynthetic

11

You are what you eat scenario

An archaeon evolved to eat bacteria which later became mitochondria
(Where did the cytoskeleton come from)

12

Old classification -4

Amoebas
Flagellates
Ciliates
Sporozoans

13

Amoebas

Lobose
Radiolarians
Foraminiferans

14

Lobose amoebas - 4

Lobopodia, driven by actin polymerisation
Predatory, engulf and digest prey in vacuoles
Aggregate into grex or syncitium
Produce fungus-like fruiting bodies

15

Grex

Multicellular lobose amoebas
Slug-like organism

16

Syncitium

Acellular lobose amoebas
Multinuclear mass of cytoplasm

17

Radiolarians

Silica shells
Long thin pseudopodia = actinopodia supported by microtubules

18

Foraminiferans

Calcium carbonate shells
Long thin reticulopodia which fuse together in a net to catch prey

19

Flagellates -6

Green algae
Dinoflagellates
Heterokonts
Euglenia
Kinetoplastids
Diplomonads, trichomonads

20

Dinoflagellates

Flagella in grooves of a shell, one forward, one helical and wrapped around cell waist
Toxic red tides
Paralytic shellfish poisoning

21

Heterokonts

One flagella hairy, forward pointing, thrust generating
Another plain, trailing backwards, used for steering
Brown algae, diatoms, oomycetes (water moulds)

22

Kinetoplastids

Parasites (sleeping sickness, chaga's disease)
One long flagellum attached to undulating membrane
One giant mitochondrion at the base of flagella (kinetoplasts)

23

Diplomonads

No mitochondrium
Giardia
Looks like 2 cells joined together
2 nuclei
8 flagella
Attach to host intestines

24

Trichomonads

No mitochondrium
Instead have hydrogenosomes that produce H2
Bundle of flagella

25

Ciliates

Cilia beat in unison driven by network of microtubules
Most complex unicellular organisms
Permanent mouth (cytostome) and gut (cytopharynx)
Predatory
2 nuclei
Macronuclei for gene expression
Micro nuclei for reproduction

26

Apicomplexans

= sporozoans
Apical complex = organelle used to penetrate host cells
Multi-host parasites
Malaria (plasmodium), toxoplasmosis

27

Closest relative of animals

Choanoflagellates (collar animalcules)
Resemble feeding cells of sponges

28

Inter-domain similarities -5

Streptomycetes = fungi
Slime moulds = myxobacteria
Yeasts = g+ cocci
Flagellates = rod-shaped bacteria
Cyanobacteria = algae