Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

EVOLUTION > Origin Of Life & Symbiosis (9) > Flashcards

Origin Of Life & Symbiosis (9) Flashcards

1
Q

Life requirements? (2)

A

• Metabolism.
• Reproduction.

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

Scenario of Earth 3.5 billion years ago? (2)

A

• No O2.
• High temperatures.

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

Who lives there in such an area 3.5 mya? (3)

A

• Prokaryotes/Bacteria.
• Archaebactria.
• Eukaryotes.

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

Prokaryotes/Bacteria attributes? (2)

A

• Rapid reproduction.
• Reproduction through binary fission.

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

How did bacteria reproduce?

A

Binary fission.

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

Which SC are bacteria associated with?

A

Biological SC.

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

Archaebactria?

A

= prokaryotic extremophiles.

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

Extremophiles?

A

= organisms that prefer/love living in extreme environments.

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

Eukaryotes?

A

= organisms that can be seen with the naked eye & are the most complex in structure.

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

Unicellular eukaryotes?

A

= have high genetic diversity.

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

How did Eukaryotes evolve from prokaryotes?

A

Discovered through Loki’s castle where Lokiarchaeota makes Archae paraphyletic & therefore eukaryotes related to Archae (prokaryotes). Therefore, prokaryotes gave rise to eukaryotes.

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

Similarity between Gram+ & Gram-?

A

• Cytoplasmic membrane.

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

Gram- bacteria attributes? (3)

A

• Outer membrane.
• Lacks teichoic acid.
• Porine enable permeability.

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

Gram+ bacteria attributes? (2)

A

• Multiple peptidoglycan layers.
• No porins.

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

Mid-Atlantic Ridge?

A

= northernmost field of hydrothermal vents.

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

Loki’s castle attributes? (5)

A

• Rich in mineral deposits.
• Habitat for Archaea (Angler fish).
• Give us a clue on origin of Archaea.
• Named after norse god, Loki.
• Lokiarchaeota.

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

Why is it a “castle”?

A

It’s because it has 5 active black smokers chimneys on large flat tops.

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

Why was Loki’s castle called Loki’s castle? (2)

A

• Difficult to find.
• Master of disguise.

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

Results of Lokiarchaeota? (2)

A

• Makes Archae paraphyletic (from monophyletic).
• Transition from 3 domain system to 2 domain system.

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

Life driving forces? (2)

A

• Food.
• Reproduction.

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

Why are the life driving forces in their specific order?

A

The need for energy through food drives endosymbiosis.

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

Food?

A

= organic compounds that are spontaneously made/slow.

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

Who consumes food?

A

Heterotrophs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Result of limited food?

A

High competition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Solution to limited food?

A

Make your own food!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Why did autotrophs exist?

A

To prevent experiencing food limitations (high competition).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Always think about what scenario?

A

Anaerobic environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Autotrophic types? (2)

A

• Chemoautotrophs.
• Photoautotrophs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Chemoautotrophs?

A

= make own food using reducing energy from chemicals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Eg of Chemoautotrophs?

A

Sulphur-bacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What problem did Chemoautotrophs experience?

A

Resource limitation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Solution to the problem of Chemoautotrophs?

A

Used H20 to reduce O2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Photoautotrophs?

A

= cyanobacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Cyanobacteria attributes? (3)

A

• Blue-green algae.
• Have chlorophyll to enable light capture.
• H2O is abundant but build up of O2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What “problem” did Photoautotrophs experience?

A

H2O abundance but build up of O2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What did Photoautotrophs use to produce O2?

A

H20.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Result of Photoautotrophs dominating landscapes?

A

They were able to make their own food well & therefore be able to reproduce.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Elaborate reasons to why O2 is not good? (2)

A

• It is a precursor of O3 and contains free radicals with high reactivity. This causes O2 to be toxic in anaerobic environments & therefore decreases the energy source of food with decreasing UV.

• At the time organisms were living in an anaerobic environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What do you do when autotrophs are breaking down your food as a heterotroph/aerobic prokaryotes?

A

Adapt.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Therefore, adapting produces? (2)

A

• High efficiency.
• High anaerobic respiration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Eg of aerobic prokaryote that adapted?

A

Alpha-proteobacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How did alpha-proteobacteria deal with the high O2 levels? (2)

A

• Used the oxidative power of O2 for complete food breakdown & maximum energy release.

• O2 as a final electron acceptor to produce water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

3 domain system in Phylogenetic tree?

A

Bacteria Archae Eukarya.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

How did early eukaryotes do to survive the high O2 levels?

A

They ate Alpha-proteobacterium (aerobic).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Why did early eukaryotes eat these?

A

Because alpha-proteobacteria offered relief from the anaerobic environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

In order to continue feeling relieved, what did the early eukaryotes do?

A

They did not digest the alpha-proteobacteria but held them hostage to receive permanent relief & to keep prokaryotes producing food for them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What did this need for permanent relief lead to?

A

In a permanent relationship between the eukaryotes & the alpha-proteobacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What did this permanent relationship ultimately lead to?

A

The development/evolution of mitochondria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What organisms then evolved from the development of mitochondria?

A

Mitochondriate eukaryotes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Mitochondriate eukaryote?

A

= true eukaryotes with mitochondria which are still heterotrophic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Are all true eukaryotes mitochondriate?

A

No, some were amitochondriate eukaryotes (protoeukaryote-like) which still had mitochondrial genes & mitochondrial remnants due to all of them being originally mitochondriate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Survivors of ME? (3)

A

• Aerobic eukaryotes LECA (Hydrogenosome mitosomes).
• Lokiarcheota.
• Aerobic alpha-proteobacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Non-survivors of ME? (3)

A

• Archae.
• Eukarya.
• Other bacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Evidence of bacterial endosymbiosis? (3)

A

• Membranes.
• DNA.
• Reproduction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Membranes attributes? (2)

A

• Indicate the type of endosymbiosis you had.
• Count number of membranes to know whether it’s Primary, Secondary or Tertiary endosymbiosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

DNA attribute/tip?

A

Observe how many DNAs it has.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What about chloroplasts?

A

Since you had heterotrophic eukaryotes with mitochondria they still had a challenge of food limits.

58
Q

How did they solve the food limits?

A

Make own food via photosynthesis.

59
Q

How could these heterotrophic eukaryotes “make their own food” via photosynthesis?

A

By eating/phagocytocizing Cyanobacteria.

60
Q

Why did the heterotrophic eukaryotes eat cyanobacteria?

A

Because of the driving force of limited food.

61
Q

Why were cyanos held hostage by mitochondriate eukaryotes?

A

Held hostage for permanent food supply.

62
Q

Result of this permanent relationship through permanent food supply?

A

Evolution of the 1st plastid/chloroplast.

63
Q

How/through what did the 1st plastid evolve?

A

Via co-evolution with the mitochondriate eukaryotes.

64
Q

What new organisms did they become when they ate Cyanobacteria?

A

Aerobic autotrophic eukaryotes.

65
Q

2 potential autotrophic food sources?

A

• Cyanobacteria (via primary endosymbiosis).

• 1st eukaryotic autotrophs (via secondary endosymbiosis).

66
Q

Mitochondrial acquisition attributes? (2)

A

• Ancient.
• Occurred once.

67
Q

Plastid acquisition attributes? (2)

A

• Very recent.
• Occurred more than once.

68
Q

Primary endosymbiosis process? (5)

A

Eukaryotic heterotroph eats Photosynthetic endosymbiont
|
Eater has food vacuole of eaten.
|
Vacuole membrane of eaten disappears.
|
Eater becomes a eukaryotic autotroph.
|
2 membranes.

69
Q

Secondary endosymbiosis process? (3)

A

Bigger eukaryotic autotroph eats smaller eukaryotic autotroph.
|
Eater digests everything of eaten except chloroplast.
|
>=3 membranes around chloroplast.

70
Q

Dinoflagellates are an eg of what type of endosymbiosis?

A

Tertiary endosymbiosis.

71
Q

How are Dinoflagellates that kind of endosymbiosis?

A

By replacing its ancient plastid of red algae origin with another algae, which also contains a plastid of red algae origin.

72
Q

What did Dinoflagellates take on/phagocytocise?

A

Red algae.

73
Q

Kinds of aerobic eukaryotes eaters? (2)

A

• Fussy eaters/ inefficient digesters.
• General eaters/ efficient digesters.

74
Q

Fussy eaters attributes? (2)

A

• Strong drive to take on/eat endosymbionts.
• Co-evolution more likely to occur.

75
Q

General eaters attribute?

A

Could look for alternative food sources.

76
Q

What do these types of aerobic eukaryotes result in? (2)

A

A radiation of eukaryotes where:

• Some + Photosynthetic endosymbionts.
• Some colourless + non-photosynthetic.

77
Q

Lateral/Horizontal evolution?

A

= mixture (not a blending) of more than 2 organisms where reticulation events lead to chimaeras (mixes of 2 separate lineages).

78
Q

Lateral evolution attributes? (2)

A

• Permanent endosymbiosis where you have mt & cp.
• Inside eukaryotic host cell.

79
Q

Original grand theft?

A

= huge leaps in “evolution”.

80
Q

Chimaeras problems? (4)

A

• Different timing of cell division.
• Differences in sexual reproduction (conjugate vs gametes).
• Each with selfish needs.
• Development from hunter-prey lifestyle to commensalism lifestyle.

81
Q

Eg of chimaera?

A

Hatena arenicola.

82
Q

How does the host ensure its survival? (2)

A

• Host must make endosymbiont captive.
• Host must control endosymbiont.

83
Q

Ways that the host makes the endosymbiont captive? (2)

A

• By synchronizing division.
• By passing it on to the next generation.

84
Q

How must the host control the endosymbiont?

A

By stealing the endosymbiont’s vital genes (lateral transfer to host nucleus).

85
Q

Evidence of lateral transfer to host nucleus?

A

Gene sequencing.

86
Q

How is endosymbiont reliance seen? (3)

A

• DNA of endosymbiont in host nucleus.
• Protein of endosymbiont made in host cytoplasm.
• Must cross at least 2 membranes.

87
Q

Sexual reproduction challenge for endosymbiont in primary endosymbiosis?

A

Eaten by prokaryotes and has to deal with conjugation.

88
Q

Sexual reproduction challenge for endosymbiont in 2ndary & Tertiary endosymbiosis?

A

Eaten by eukaryote & has to deal with syngamy & gametes.

89
Q

Sexual reproduction challenge for host in endosymbiosis?

A

Host must retain but accommodate endosymbiont.

90
Q

Types of gamy/reproduction? (3)

A

• Isogamy.
• Anisogamy.
• Oogamy.

91
Q

Isogamy attributes? (2)

A

• Both gametes swim.
• Same size.

92
Q

Anisogamy attributes? (2)

A

• Egg & Sperm different size.
• Both gametes swim.

93
Q

Oogamy attributes? (2)

A

• Egg & Sperm different size.
• Egg can’t swim, Sperm can swim.

94
Q

How are endosymbionts passed on in Isogamy?

A

Both partners contribute their organelles.

95
Q

How are endosymbionts passed on in Anisogamy?

A

Only female contributes because of big gamete size.

96
Q

How are endosymbionts passed on in Oogamy?

A

Only female contributes organelles.

97
Q

Eg of an exception of how endosymbionts are passed on?

A

Yellow wood trees.

98
Q

Heterotroph?

A

= organism that obtains energy by feeding on other organisms.

99
Q

Autotroph?

A

= organism that makes its own food from inorganic substances/ from the environment.

100
Q

Chemotroph?

A

= organism that makes their own food using reducing energy from chemicals.

101
Q

Eukaryote?

A

= organism that has cells with a complex internal structure.

102
Q

Prokaryote?

A

= single-celled organism that lacks membrane-bound organelles with its DNA free in the cytoplasm.

103
Q

Endosymbiosis?

A

= mutually beneficial relationship where one organism lives within another organism.

104
Q

Aerobic?

A

= with O2.

105
Q

Anaerobic?

A

= without O2.

106
Q

Cyanobacterium?

A

= photosynthetic bacteria that contain chlorophyll & release O2 during photosynthesis.

107
Q

Mitochondria?

A

= powerhouses of the cell.

108
Q

H2 hypothesis?

A

= states that a H2-producing aerobic bacteria & a H2-consuming anaerobic Archae grew along each other until the Archae engulfed the bacteria.

109
Q

Result of high levels of O2?

A

Posed a problem as they were in an anaerobic environment.

110
Q

Why is O2 not good? (2)

A

• Precursor of O3.
• Toxic in an anaerobic environment.

111
Q

What did the alpha-proteobacteria produce? (2)

A

• CO2.
• H2O.

112
Q

Refugia?

A

= space that remains the same & enables lineages to survive extinction events.

113
Q

Term used to describe the amitochondriate eukaryotes?

A

Hydrogenosomes.

114
Q

Hydrogen hypothesis attributes? (4)

A

• Bacterial cell used H2 as a form of reduction energy to make it’s own food.
• Facultative endosymbiont’s anaerobic metabolism (H2 waste).
• Anaerobic host uses H2 (chemoautotroph).
• Hydrogenosome first, then mitochondria.

115
Q

Hydrogen hypothesis?

A

= states that mitochondria acquisition is not driven by O2.

116
Q

Syntrophy?

A

= eating together.

117
Q

Similarity/Thing to note about Red & Green algae?

A

Both are Gram- bacteria.

118
Q

Plastidial endosymbiosis attributes? (2)

A

• Common & distributed across tree of life.
• Not always independently, but could be eaten again & again.

119
Q

Protist groups arising from red algae? (3)

A

• Dinoflagellates.
• Apicomplexans.
• Stramenopiles.

120
Q

Protist groups arising from green algae? (2)

A

• Euglenids.
• Chlorarachniophytes.

121
Q

Egs of SA’s dinoflagellates? (3)

A

• Durinskia capensis.
• Amphidinium latum.
• Rhodomonas.

122
Q

What did Durinskia capensis eat?

A

Red algae.

123
Q

What did Amphidinium latum eat? (2)

A

• Brown algae.
• Green algae.

124
Q

What did Rhodomonas eat?

A

Red algae.

125
Q

Result of chimeraes?

A

Enables Original grand theft.

126
Q

What drove lateral evolution?

A

Food limitation (selection pressure).

127
Q

Endosymbiont?

A

= microbial cell that lives inside a microbial host.

128
Q

Endosymbiont attributes? (3)

A

• Cyanobacteria were inside heterotrophic eukaryote.

• Red/Green algae were inside heterotrophic eukaryote.

• Endosymbiont relationship gives rise to plastids.

129
Q

Eg of an endosymbiont?

A

Durinskia capensis in SA.

130
Q

Plastid?

A

= double membrane organelles inside plants/algae.

131
Q

Egs of plastids? (3)

A

• Chloroplasts.
• Chromoplasts.
• Leucoplasts.

132
Q

List of the primary plastids? (2)

A

• Red algae.
• Green algae.

133
Q

What happened to the red & green algae?

A

They were genetically integrated with the host cells & gave rise to a variety of protist groups.

134
Q

Hatena arenicola attributes? (2)

A

• Heterotrophic flagellate.
• Eats Nephroselmis.

135
Q

Why is the size of gametes important?

A

It’s because it determines how the endosymbiont is transferred to future generations.

136
Q

Types of DNA? (2)

A

• Mitochondrial DNA.
• Chloroplastic DNA.

137
Q

Which side of the family do mt DNA & cp DNA come from?

A

Maternal side of the family.

138
Q

Through which family are mt DNA & cp DNA passed on to the next generation?

A

Via the maternal side of the family.

139
Q

Why are mt DNA & cp DNA passed on via the maternal side of the family?

A

It’s because there’s more space in female gametes.

140
Q

What’s the benefit of us knowing about how endosymbionts are transferred in subsequent generations?

A

It gives us an idea of plastid evolution & diversification across groups.

141
Q

What was the implication of plastid evolution & diversification across groups?

A

The transferring of species from the prokaryotic world to the eukaryotic world has caused a significant increase in global productivity.

EVOLUTION (12 decks)

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