Protists Key Facts Flashcards
(132 cards)
1
Q
What size are protist cell typically ?
A
50-1000 micrometres
2
Q
What are protists?
A
Eukaryotic microorganisms that can be unicellular or multicellular
But main unicellular
3
Q
Name the three forms of protists.
A
- Ciliates
- Flagellates
- Amoebae
4
Q
What distinguishes eukaryotic cells from prokaryotic cells?
A
Eukaryotic cells have a nucleus and membranous organelles
5
Q
What are the three modes of nutrition in protists?
A
- Photoautotrophic
- Heterotrophic
- Mixotrophic
6
Q
Describe how mixotrophy is achieved in protists.
A
Through selective digestion or no digestion of algal cells
7
Q
What major organelles are found in eukaryotic protists?
A
- Nucleus
- Mitochondrion
- Golgi apparatus
- Endoplasmic Reticulum
- Chloroplast
8
Q
What is the main difference between prokaryotic and eukaryotic ribosomes?
A
Prokaryotic ribosomes are 70S, while eukaryotic ribosomes are 80S
9
Q
True or False: All protists have a cell wall.
A
False
10
Q
Fill in the blank: The largest amoeba is ______ cm.
A
10
11
Q
What is the primary method of movement in protists?
A
Cilia and flagella
12
Q
What is the significance of the endosymbiont theory?
A
It explains the origin of mitochondria and plastids in eukaryotic cells
13
Q
What oxygen grouped organisms can survive ?
A
Obligate aerobes - need O2 for growth
Obligate anaerobes - cannot grow in presence of O2
14
Q
Describe the cytoskeleton in protists.
A
A network of proteins like tubulin and actin throughout the cytoplasm
15
Q
What are the advantages of cysts in protists?
A
- Resistance to heat
- Resistance to drying
- Resistance to radiation
- Good dispersal mechanism
16
Q
What is the difference in cell wall composition between protists and bacteria?
A
Protists may have cell walls made of cellulose or silica, while bacteria typically have peptidoglycan
17
Q
What is meant by mixotrophic protists?
A
Protists that can perform both photosynthesis and heterotrophy
18
Q
What is the primary method of reproduction in protists?
A
Mitosis
19
Q
What is a food vacuole in protists?
A
A structure that helps in digestion and recycling of membranes
20
Q
True or False: All protists reproduce sexually.
A
False
21
Q
What are the characteristics of obligate anaerobes?
A
Cannot grow in the presence of O2
22
Q
What is the significance of ribosomes in organelles?
A
Eukaryotic organelles contain 70S ribosomes
23
Q
Fill in the blank: The cytoplasmic membrane separates the ______ from the outside.
A
Cytoplasm
24
Q
What is soluble debris?
A
A type of organic material that can dissolve in a liquid
Often relevant in studies of cellular processes and nutrition in protists.
25
What is membrane recycling?
The process of reusing cellular membranes for various functions
## Footnote
Important for maintaining cellular integrity and function in protists.
26
What is organellar mixotrophy?
A mode of nutrition where protists utilize organelles for energy production
Eats algal cells, doesn’t digest the plastids (kleptoplastids)
Plastids fix CO2
Plastids do not encode for polymerases
Die and need replenishing so eats more
Can live without them
## Footnote
Involves selective digestion of algal cells.
27
What are kleptoplastids?
Plastids that are taken from algal cells and not digested by the protist
## Footnote
They fix CO2 but do not encode for polymerases.
28
What happens to plastids in protists?
Plastids die and need replenishing, leading protists to consume more algae
## Footnote
Protists can survive without plastids.
29
What is cellular mixotrophy?
A mode of nutrition where protists consume algal cells without digesting them
## Footnote
Algae can still divide within the protist's cell.
30
True or False: Protists can live without the algae they consume in cellular mixotrophy.
True
## Footnote
This indicates a level of independence in protist nutrition.
31
What are constitutive mixotrophs?
Protists where algal cells evolve into true organelles over time
## Footnote
This involves complex genetic transfer events.
32
Which protists are known for constitutive mixotrophy?
Only seen in flagellates
## Footnote
These protists rely entirely on the endosymbiotic algae.
33
Name the three modes of mixotrophy in protists.
* Organellar mixotrophy
* Cellular mixotrophy
* Constitutive mixotrophy
## Footnote
Each mode reflects different strategies for energy acquisition.
34
What are the two main types of movement in protists?
* Flagellum/flagella
* Cilium/Cilia
## Footnote
Movement is crucial for searching and capturing prey.
35
What are the three forms of protists?
* Ciliates
* Flagellates
* Amoebae
## Footnote
These forms represent the diversity within the protist kingdom.
36
What is the size range of protists?
Generally microscopic, ranging from a few micrometers to several millimeters
## Footnote
Their size differs significantly from prokaryotic cells.
37
What are the similarities between protists and bacterial cells?
* Both are unicellular
* Both can have similar cellular structures
## Footnote
These similarities help in understanding evolutionary relationships.
38
What are the differences between protists and bacterial cells?
* Protists are eukaryotic, bacteria are prokaryotic
* Protists have membrane-bound organelles, bacteria do not
## Footnote
These differences are fundamental to cellular biology.
39
How does light affect mixotrophy in protists?
* High light: Photosynthesis > feeding
* Low light: Feeding > photosynthesis
## Footnote
This adaptation allows protists to optimize energy acquisition.
40
What is the largest amoeba ?
10cm
41
Asexual
Mitosis
42
How does the growth curve differ in protists from bacteria ?
It is the same growth curve as in bacteria
43
Is protist replication longer than bacterial binary fission ?
Yes , at the same temperature it can take hours/days
44
A cell wall is always present in ……..
Non-motile photosynthetic protists
E.g diatoms
All cysts
45
A cell wall is not present in …….
Motile photosynthetic protists
Heterotrophic protists
Mixotrophic protists
46
Why do marine species not need a contractile vacuole ?
The water potential is the same in the seawater as in the embryonic cells. No cell wall but still osmosis
47
Where is the cut off in temperature and protist growth ?
I.e which type of temperature grouped organisms cannot survive ?
60 degrees
Hyper thermophiles
48
How is ATP produced aerobically and anaerobically in protists ?
O2 —> CO2 in mitochondria
Pyruvate —> H2, Acetate, CO2. Hydrogenosomes
49
Which bacterium became a mitochondrion and a chloroplast in the endosymbiont theory ?
Alpha-proteobacterium - became a mitochondrion
Hydrogenosome - evolved from a mitochondrion
Cyanobacterium - became a chloroplast
50
Describe cellular mixotrophy
Eats algal cells
No digestion of algae ( not just plastids )
Algae divide in cell
Protist can live without the algae
51
Describe constitutive mixotrophy
Algae evolve into organelles over time
Endosymbiotic algae become true organelles
Protist cannot live without them
Only seen in flagellates
52
Which protists carry out organellar mixotrophy ?
Ciliates and amoebae
53
Which protists carry out cellular mixotrophy
Ciliates and amoebae
54
Which protists carry out constitutive mixotrophy ?
Flagellates
55
In high light is photosynthesis preferred or feeding ?
Photosynthesis
56
What are protists?
Eukaryotic organisms that are not animals, plants, or fungi.
57
What are the three forms of protists?
* Ciliates
* Flagellates
* Amoebae
58
What is the significance of mixotrophy in protists?
Mixotrophy allows protists to acquire nutrients through multiple modes.
59
What are the three types of carbon acquisition in protists?
* Photoautotrophy
* Heterotrophy
* Mixotrophy
60
What are cilia?
Microtubule-based hair-like organelles used for movement and feeding.
61
What are the two types of nuclei found in ciliates?
* Macronucleus
* Micronuclei
62
What is the role of the cytostome in ciliates?
It functions as the mouth for ingesting food.
63
What is the function of the cytoproct in ciliates?
It serves as the anus for expelling waste.
64
What is the structure of motile cilia?
9+2 arrangement with dynein motor protein.
65
What is transverse binary fission?
Asexual reproduction involving mitosis to produce two daughter cells.
66
What distinguishes raptorial feeding from filter feeding?
Raptorial feeding involves actively capturing prey, while filter feeding involves sifting food from water.
67
True or False: All protists possess a cell wall.
False
68
What are hydrogenosomes?
Organelles found in anaerobic ciliates that produce hydrogen and acetate.
69
What is the primary mode of reproduction in flagellates?
Longitudinal binary fission.
70
What is the function of the flagellum in flagellates?
Used for movement and capturing prey.
71
Name the four Eukaryote supergroups.
* Excavata
* SAR
* Archaeplastida
* Unikonta
72
What is the difference between heterotrophic and photoautotrophic flagellates?
* Heterotrophic: consume pre-formed organic carbon
* Photoautotrophic: possess plastids and perform photosynthesis
73
Fill in the blank: Mixotrophic flagellates can ingest prey and have their own _______.
plastids
74
What are choanoflagellates known for?
Having a collar of tentacles and being closely related to animals.
75
What is the role of the eyespot/stigma in Euglena?
It detects light direction for photoreception.
76
What is the significance of conjugation in ciliates?
It allows for genetic variation through the exchange of micronuclei.
77
What is an example of a mixotrophic flagellate that forms colonies ?
Dinobryon
78
What type of feeding do suctorian ciliates exhibit?
Raptorial feeding using microtubule tentacles.
79
What are extrusomes in ciliates used for?
To secrete toxins and digest prey.
80
Fill in the blank: Ciliates are the most developed _______.
protozoan
81
What is the other type of ciliate to free-swimming ?
Sessile - usually attached
82
What is the arrangement In non-motile cilia ?
9+0 , no dynein motor protein
‘Primary cilia’ on all human cells
83
Why are cilia important for filter feeding ?
They direct prey towards the mouth area (cytostome)
Cytostome contains stiffer cilia ( membranelles)
Sieve - correct sized prey enter food vacuoles
84
Describe vorticella
The prey is drawn towards the cell
The vortex is at the cell mouth
Very large feeding currents
85
What is the exception to the rule of ciliates having cilia in their adult form
Suctorian ciliates
86
Describe how suctorial ciliates carry out raptorial feeding
Numerous micro tubule tentacles
Each tentacle ends with a cytostome
Extrusomes -secrete toxins
Dissolve prey contents and suck out
‘Raptorial feeding’
87
Describe sexual reproduction in ciliate reproduction
Advantage ?
Conjugation
Involves meiosis and mitosis
Μicro-nuclei swap
Allows for genetic variation
88
Are sulphur ciliates aerobic or anaerobic?
Anaerobic
Pyruvate —-> converted to H2 , Acetate and CO2 by hydrogenosomes.
Methanogenic bacteria produces methane
89
What arrangement of flagella do flagellates have ?
Is movement multidirectional ?
Flagella (9+2)
No, movement is unidirectional
90
Do flagellates have a micro and a macro nucleus ?
No, just a macronucleus
91
92
Are flagellates aerobic or anaerobic ?
Mainly aerobic
93
What methods of nutrition can flagellates do ?
Heterotrophy, photoautotrophy, mixotrophy
94
Which type of flagellates are also called zoo flagellates ?
Heterotrophic flagellates
95
What types of feeding do heterotrophic flagellates carry out ?
Raptorial
Filter
96
What is the advantage of a hispid flagellum ?
Creates feeding currents due to flagellates movement
Prey is drawn towards the base of the flagellum
Ingested via cytoplasmic extensions (pseudopodia)
97
How can filter feeding with a naked flagellum be made more efficient ?
Collar of tentacles (microvilli)
Contains actin - contractile
98
Silica lorica are in which choanoflagellates only ?
Marine
99
True / False , protist lorica structure has influenced engineering of complex buildings
True
100
101
What is the only type of flagellate to have a 2nd flagellum around the waist ?
Dinoflagellates
102
What are 2 examples of flagellate colonies ? ( not multicellular )
Synura
Volvox
103
Are mixotrophic flagellates aerobic or anaerobic ?
All aerobic
104
What is an example of a solitary mixotrophic flagellate ?
Ochromonas
Few plastids
Prefers to feed on prey
105
Which type of protist can be purely photoautotrophic ?
Flagellates
106
Flagellates do ………. Reproduction
Ciliates do ……… and ……… reproduction
Asexual
Asexual and sexual
107
Do amoebae have a macro or a µ nucleus or both
Just macro
108
Are amoebae aerobic or anaerobic?
Aerobic
109
Are most amoebae mixotrophic ?
No, most are heterotrophic , some are mixotrophic
110
Do amoebae carry out sexual reproduction or asexual reproduction?
Asexual only
111
112
Which supergroups are archaea in ?
Excavata
SAR
Arcaeplastida
Unikonta
113
How do naked amoebae feed ?
Move by cytoplasmic streaming
Produce pseudopodia on surfaces
Raptorial feeding
114
What are the 3 cell forms of naked amoebae ?
Trophozoites - feeding form
Cysts - all produce a resting stage
Floating form - stiffened pseudopodia for dispersal
115
Describe shelled amoebae’s feeding
Raptorial or diffusion feeding
116
Can shelled amoebae produce cysts ?
What are the 2 types of cytoplasm they possess?
Yes , they can produce cysts
Intrashellular cytoplasm within test
project extrashellular cytoplasm to move/ and or feed
117
Describe testate amoebae
Freshwater , marine and terrestrial
- raptorial feeding
118
Describe foraminiferans
Marine only
CaCO3 tests
Diffusion feeding
119
Describe radiolarians
Marine amoebae only
Silica tests
Diffusion
120
Describe heliozoans
Freshwater
Silica tests
Diffusion
121
What are some benefits of protists ?
Microbes - base of every food chain
Keep bacterial populations healthy
Important in nutrient cycling
122
What is a bad point about protists ?
Mainly amoebae -
Allow the evolution of new bacterial pathogens
Acts as a reservoir for them too
123
What does protists eating bacteria do ?
Stops bacteria reaching their carrying capacity
124
What do protists have to maintain their cellular C:N:P ratio at ?
50:10:1
125
Bacteria have evolved to be able to evade digestion in amoebae so what can we describe amoebae as ?
A reservoir for pathogenic bacteria
126
What Protist is naturally present in the gut ?
Entamoeba coli. - it is non pathogenic
127
Entamoeba histolytica, Balantidium coli, Giardia lamblia are all ……. Caused by protists
What symptom do they cause ?
Reservoir and transport ?
Treatment
Gut infections
Dysentery , all produce cysts
Water , animals / humans
Contaminated water , faecal-oral route
Treatable but takes months due to intermittent cysts
128
What eye infection is caused by protists ?
Transport ?
Is it treatable ?
Keratitis caused by Acanthamoeba
Reservoir : water
Dirty contact lenses , H2O2 must be present in contact lens cleanser
Yes, but it can lead to glaucoma
129
What is the brain eating amoeba ?
What does it cause ?
Reservoir ?
Transmission ?
Naegleria fowleri
PAM - primary amoebic meningoencephalitis
Warm water
Flagellate swims up nose , fatal in two weeks
130
What STD is caused by a protist ?
What does it cause ?
One flagellate - Trichomonas vaginalis
Trichomoniasis
131
Is trichomonas vaginalis aerobic or anaerobic ?
Cysts ?
What does it infect ?
Transmission + treatable ?
Anaerobic
No cysts
Urethra , vagina , prostate
Humans , sexual intercourse, asymptomatic males , treatable
132
What blood / tissue infection is caused by prostists ?
Reservoir
Transmission
2 types of infection
Flagellate - Leishmania Mexicana
Causes leishmaniasis
Aerobic, no cysts
Reservoir - Dogs
Transmission : sand fly (vector)
Visceral
Cutaneous : infects macrophages and divides within
Treatable
