Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIO 121 > Key stuff - Protists and Amoebae > Flashcards

Key stuff - Protists and Amoebae Flashcards

(57 cards)

Start Studying
1
Q

What are protists

A

eukaryotes

majority are single celled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cytoskeleton

A

for trafficking organelles

allow movement of organelles to correct ares, specific areas.

(tubular, actin, throughout cytoplasm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Photoautotrophic protists

A

contain plastids (green, red or golden)

green plastid = chloroplast

photosynthesis

Termed ‘Algae’ (some have a cell wall)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Heterotrophic protists

A

feed on bacteria, fungi and other protists

termed ‘Protozoa’ (‘first animals’) (none have a cell wall)

Bacteria is ‘favourite’ prey.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Mixotrophic bacteria

A

Feed on bacteria, fungi and other protists and photosynthesise (none have a cell wall)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Direct microscopic count.

A

easy and fast

Uses special microscope counting slide

-does not differentiate between live and dead bacteria

motile protists have to be killed as easier to count.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Same population growth curve. as bacteria:

A

Lag phase- Time interval between inoculation and maximal division rate: cells adjust to new environment.

Log phase- constant doubling time, growth rate is maximal

stationary phase- can no longer reproduce but are still alive (e.g no food left)

death (decline) phase- death or cyst formation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cysts

A

Produced under unfavourable conditions

highly resistant to heat, drying and radiation.

very low water content

can survive for 20 years I the environment

good resistance to antibiotics/disinfectants

effective dispersal mechanism (can be transmitted to others via faeces)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cell walls of protists

A

Always present in:
non-motile photosynthetic protists
cysts (even if protist that produced them does not have a cell wall)

Not present in:
motile photosynthetic protists
heterotrophic protists
mixotrophic protists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Temperature cut off

A

60

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Oxygen and protist growth

A

Obligate aerobes

Obligate anaerobes

‘jury’ is out to whether we have microaerophillic eukaryotes (current investigation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Respiration

A

Aerobic - mitochondria

anaerobic- hydrogenosomes
(pyruvate to H2, acetate, co2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What became a mitochondrion after endosymbiosis?

A

alpha-proteobacterium

hydrogenosome evolved from mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What became chloroplasts after endosymbiosis

A

cyanobacterium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Food vacuole (phagosome) dynamics in protists

A

only certain part of membrane used for feeding.

bacterium to receptors, then phagocytosis stuff, membrane recycling

soluble and insoluble debris released by exocytosis.

if food escapes, it will take membrane of phagosome. will have 2 membranes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Organellar mixotrophy

A

-eats algal cells

-does not digest plastids (kleptoplastids)

-plastids fix co2

-plastids do not encode for polymerases

-die and need replenishing (so eats more)

-protist can live without the plastids

-ciliates and amoebae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

cellular mixotrophy

A

-eats algal cells

-no digestion oof algae

-algae fix co2

-algae divide in cell

-protist can live without the algae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

constitutive mixotrophs

A

over time and through complicated genetic transfer events

endosymbiotic algae become true organelles

only seen in flagellates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Ciliates

A

covered in cilia

most developed protozoan

cytosine (mouth)

cytoproct (anus)

Two types of nucleus:
-macronucleus
-micronuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Cilia

A

Microtuble-based hair-like organelles

used for movement
-go back and forward
-some fuse to form ‘cirri’

very important for feeding
-direct prey towards the mouth are (‘cytostome’
-cytostome contains stiffer cilia (‘membranelles’)
-sieve- correct sized prey enter food vacuoles
-‘filter feeding’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Motile cilia

A

9+2, dyne motor protein

ciliates

humans (bronchial and oviduct epithelium)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

non-motile cilium

A

9+0, no dyne motor protein

‘primary cilium’ on all human cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

prey drawn towards cell

vortex at cell mouth

very large feeding currents

‘Mexican wave’ by cilia on top forms vortex of water which draws prey towards oral area. Scared and easily contracts on impact.

24
Q

Suctarian ciliates

Study These Flashcards
A

numerous microtubule tentacles

each tentacle ends with a cytostome

extrusomes - secrete toxins

dissolve prey contents and suck out.

‘raptorial feeding’

25
mixotrophic ciliates
do not acquire their own plastids acquire photoautotrophic ability two ways organelle mixotrophy and cellular mixotrophy.
26
Macronuclues
Controls the cell.
27
Micronucleus
only used for sexual reproduction
28
Ciliate reproduction
Asexual reproduction: -transverse 'binary fission' -involves mitosis Sexual reproduction -conjugation -involves meiosis and mitosis -micronuclei swap -allows for genetic variation.
29
Flagellates
possesses flagellum/flagella (9+2) -not backwards and forwards -in humans- sperm possesses macronucleus only -longitudinal 'binary fission' mainly aerobic feed by heterotrophy, photoautotrophy and mixotrophy.
30
Heterotrophic flagellates
also called 'zoo flagellates' most are aerobic consume pre-formed organic carbon prey digestion -organic carbon to inorganic carbon (mineralisation) use flagella for movement and catching prey -raptorial feeding -filter feeding
31
Naked flagellum
forward swimming
32
Hipsid flagellum
backwards swimming
33
Raptorial feeding (with hips flagellum)
create feeding currents due to flagellar movement prey is drawn towards the base of the flagellum ingested via cytoplasmic extension (pseudopodia) more efficient , base of flagella only place of ingestion.
34
Raptorial feeding (with naked flagellum)
create feeding currents due to flagellar movement less contact with the base of the flagellum less efficient capture of prey
35
Increasing prey capture (with a naked flagellum)
extensions to cell. catches prey at base of flagellum covered in scales(drawing pins) pierce prey and move around surface of cell. collar of tentacles (microvilli) contain actin - contractile
36
Choanoflagellates
only group with a collar of tentacles all have a single naked flagellum attach to surface (by means of a stalk) more closely related to animals than other protists.
37
silica lorica made only in choanoflagellates, how are they made.
Mother cell makes loads of little glass strips. Glues together in right places. Bundle produced. Goes on to divide and daughter cell is pushed into two bundles and then released. Collar of tentacles grabs top of the bundle, then turns round one and a half 2 times and then tentacles pull everything up. Bundle now expands and becomes fully built lorica.
38
biomimetic engineering
due to twist of lorica. gives enhanced strength and rigidity.
39
photoautotrophic flagellates
also called 'phytoflagellates' own plastids - green or golden all are aerobic use flagella for movement towards light and nutrients.
40
Euglena (photoreception)
eyespot/stigma: organelle containing carotenoid lipid globules. Shading device for photoreceptor to detect direction of light.
41
Dinoflagellates
contain a second flagellum around the waist.
42
Amoebae
One macronucleus most are aerobic most are heterotrophic -some mixotrophic asexual reproduction only -no specific fission plane (can divide across any part of their membrane, not controlled. some move, some are stationary most publicised protozoan.
43
Naked amoebae
move by cytoplasmic streaming produce pseudopodia on surface pseudo phobia used to creep across surfaces feed by direct interception of prey raptorial feeding no specific location of ingestion - can be anywhere.
44
Naked amoebae - 3 cell forms
Trophozoites - the feeding form cysts- all produce a resting stage floating form- stiffened pseudopodia for dispersal all amoeba produce cysts.
45
Shelled amoebae
enclosed in shell ('test') shell can be made of anything intrashellular cytoplasm within test project extrashellular cytoplasm to move and/ or feed. raptorial or diffusion feeding can produce cysts.
46
Testate amoebae
freshwater, marine and terrestrial raptorial feeding made shells out of spent algae
47
Foraminiferans
marine only CaCO3 tests diffusion feeding
48
diffusion feeding
stationary predator captures prey with sticky extrashellular cytoplasm ('axopodia')
49
Radiolarians
marine only silica tests diffusion feeding
50
heliozoans
freshwater silica tests diffusion feeding
51
Good ecological impact of protists
The microbial loop. predation keeps bacteria in 'log phase'
52
Protists cellular C:N:P ratio
50:10:1 has to be maintained at this, excess released.
53
Bad ecological impact
evolution of pathogens evident in amoebae as share many similarities with macrophages bacteria practice evading digestion in amoebae become pathogenic and evade our immune system.
54
Evading digestion in amoebae
either change antigens so not recognised by receptors. be covered in a thick capsule so not detected, receptors cannot bind or can release chemicals which prevent the digestive enzymes fusing with the phagosome.
55
How much of human cells are bacterial
90% one protist naturally present
56
Visceral
attacks tissues
57
Cutaneous
infects macrophages and divides within

BIO 121 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions