Section 24.2 (Exam 1)

Question 1

What are the 8 groups of bacteria that have received the most study?

Answer 1

Hadobacteria, Hyperthermophilic bacteria, Firmicutes, Actinobacteria, Cyanobacteria, Spirochete, Chlamydias, Proteobacteria

Question 2

Define extremophiles.

Answer 2

Extremophiles thrive in extreme conditions that would kill most other organisms.

Question 3

Hadobacteria are _________. Name some examples of hadobacteria.

Answer 3

Thermophiles; Deinococcus and Thermus aquaticus

Question 4

Describe some characteristics of the hadobacteria Deinococcus

Answer 4

Resistant to radiation, consume nuclear waste, survive in both extreme cold and heat

Question 5

Describe some characteristics of the hadobacteria Thermus aquaticus.

Answer 5

found in a hot spring, source of thermally stable DNA polymerase, critical for development of PCR (Polymerase chain reaction, used to amplify DNA sequences)

Question 6

What is DNA polymerase?

Answer 6

an enzyme that copies DNA strands

Question 7

Hyperthermophilic bacteria are extreme thermophiles. They live in hot springs, near volcanic vents, deep oil deposits, and other hot environments. Name two hyperthermophilic bacteria.

Answer 7

Aquifex and Thermotoga

Question 8

Where do Aquifex live?

Answer 8

Volcanic vents

Question 9

Where do Thermotoga live?

Answer 9

Oil reserves

Question 10

What does it mean to be low or high-GC?

Answer 10

Low-GC means a low ratio of G-C to A-T base pairs in DNA. High-GC means more G-C than A-T.

Question 11

Firmicutes are low or high GC? Are they Gram-positive or negative?

Answer 11

low-GC; Gram-positive

Question 12

Some firmicutes produce ___________, heat resistant resting structures with tough cell walls and spore coats that can survive harsh conditions because they are dormant.

Answer 12

endospores

Question 13

Name some firmicutes.

Answer 13

Clostridium, Bacillus, Staphylococcus, Streptococcus, and Mycoplasmas

Question 14

What can Clostridium (a type of firmicute) cause?

Answer 14

botulism and tetanus

Question 15

When do bacillus anthracis (anthrax, also a type of firmicute) endospores activate?

Answer 15

When they sense the presence of macrophages in mammal blood.

Question 16

Staphylococcus bacteria (a type of firmicute) can cause what kinds of problems?

Answer 16

Boils and skin problems.

Question 17

What does Staphylococcus aureus cause?

Answer 17

Skin diseases, respiratory infections, and intestinal infections.

Question 18

What are some characteristics of mycoplasmas?

Answer 18

They have no cell wall, they are extremely small, and they have less than half as much DNA as other prokaryotes.

Question 19

Actinobacteria are low or high GC? Are they Gram-positive or negative?

Answer 19

high-GC; Gram-positive

Question 20

What are some characteristics of actinobacteria?

Answer 20

Elaborately branching filaments, some reproduce by forming chains of spores at filament tips, most antibiotics come from actinobacteria

Question 21

What are some examples of actinobacteria?

Answer 21

Mycobacterium tuberculosis and Streptomyces (produce streptomycin).

Question 22

What are some characteristics of cyanobacteria?

Answer 22

blue-green, photosynthetic, use chlorophyll a, many species fix nitrogen, have internal membrane system

Question 23

What are photosynthetic lamellae?

Answer 23

The internal membrane system of cyanobacteria that performs photosynthesis.

Question 24

What are eukaryote chloroplasts derived from?

Answer 24

Endosymbiotic cyanobacteria

Question 25

Are cyanobacteria free-living or colonial?

Answer 25

They can be either!

Question 26

Some colonies of cyanobacteria differentiate. What can they differentiate into?

Answer 26

Vegetative cells, spores, or heterocysts

Question 27

What do vegetative cells do?

Answer 27

Perform photosynthetic functions.

Question 28

What is the purpose of spores in cyanobacteria?

Answer 28

To endure harsh conditions and environments. The cells can lie dormant, and activate whenever they reach an environment they can survive in.

Question 29

What are heterocysts and what do they do?

Answer 29

Heterocysts are specialized cyanobacteria cells that can fix nitrogen from nitrogen gas (N2) into a usable form like ammonia (NH3)

Question 30

Name some characteristics of spirochetes.

Answer 30

Gram-negative, motile, unique axial filaments (modified flagella) resulting in corkscrew-like movement, many human parasites and pathogens

Question 31

Name some types of spirochetes.

Answer 31

Syphillis and Borrelia burgdorferi (Lyme disease)

Question 32

Name some characteristics of chlamydia.

Answer 32

Very small, Gram-negative cocci, pathogens, take up ATP from host using translocase, complex life cycle with two forms

Question 33

What are the two forms of the complex life cycle of chlamydia, and how does chlamydia cycle between them?

Answer 33

Elementary bodies grow into reticulate bodies, which multiply into elementary bodies.

Question 34

What problems can chlamydias cause?

Answer 34

They are pathogens that can cause eye infections, STDs, and some forms of pneumonia.

Question 35

Proteobacteria is the ___________ group of bacteria, meaning high diversity,

Answer 35

largest

Question 36

Eukaryote mitochondria are derived from an endosymbiotic _____________.

Answer 36

proteobacterium

Question 37

What are some examples of proteobacteria?

Answer 37

E. coli, Rhizobium (rhizobacteria, nitrogen-fixers), Yersinia pestis, salmonella typhimurium, Vibrio cholerae, agrobacterium tumefaciens

Question 38

What is Yersinia pestis, a proteobacterium, commonly known as?

Answer 38

bubonic plague

Question 39

What is salmonella typhimurium, a proteobacterium, commonly known as?

Answer 39

Salmonella, a type of gastrointestinal disease

Question 40

What is Vibrio cholerae, a proteobacterium, commonly known as?

Answer 40

Cholera

Question 41

Some proteobacterium do photosynthesis using __________________ as an electron donor, producing sulfur as a byproduct.

Answer 41

hydrogen sulfide (H2S)

Question 42

Agrobacterium tumefaciens causes a type of plant tumor called ____________. It also has a plasmid used as a vector in recombinant DNA technology.

Answer 42

Crown gall

Question 43

Archaea being a separate domain was originally based on _________________.

Answer 43

rRNA gene sequencing

Question 44

Archaea are famous for living in __________________, such as high salinity, high temperatures, high or low pH, and low oxygen.

Answer 44

extreme conditions

Question 45

Not all Archaea are extremophiles. True or False?

Answer 45

True

Question 46

Archaea do not have _______________ in their cell walls, but Bacteria do.

Answer 46

peptidoglycan

Question 47

Bacterial and eukaryotic membrane lipids have fatty acids connected to glycerol by ________ linkages.

Answer 47

ester

Question 48

Archaea membrane lipids have fatty acids linked to glycerol by _________ linkages.

Answer 48

ether

Question 49

Archaea have lipids with _______________________ chains.

Answer 49

branched hydrocarbon

Question 50

Like bacteria and eukaryotes, some archaea have cell membranes that consist of a _________________.

Answer 50

lipid bilayer

Question 51

Unlike bacteria and eukaryotes, some archaea have long-chain hydrocarbons that span the cell membrane, which is formed by a ________________.

Answer 51

lipid monolayer

Question 52

What are the 5 lineages of prokaryote archaea?

Answer 52

Euyarchaeota, Crenarchaeota, Thaumarchaeota, Korarchaeota, Lokiarchaeota

Question 53

What are some types of euryarchaeotes?

Answer 53

Some are methanogens and some are halophiles.

Question 54

What are methanogens?

Answer 54

They produce methane by reducing CO2, and are obligate anaerobes. They live in the guts of grazing mammals (cows), termites, and cockroaches.

Question 55

What are obligate anaerobes?

Answer 55

They can only survive without oxygen. Thus, the anaerobic aspect of them is obligatory.

Question 56

What are extreme halophiles?

Answer 56

They love salt, and have pink carotenoid pigments. They also live in extremely alkaline (basic) environments.

Question 57

Some halophiles have a unique system for using light to form ATP using the light-absorbing molecule ________________.

Answer 57

bacteriorhodopsin

Question 58

Thermoplasma is a type of euryarchaeote. Name some of its characteristics.

Answer 58

Thermophilic and acidophilic, aerobic metabolism, no cell wall, lives in coal deposits, smallest genome of archaea (like mycoplasma)

Question 59

Most crenarchaeotes are _____________________.

Answer 59

thermophilic, acidophilic, or both

Question 60

Example of a crenarchaeote that lives in hot sulfur springs that have a pH of 2-3.

Answer 60

Sulfolobus

Question 61

Korarchaeotes and thaumarchaeotes are only known from DNA isolated directly from __________________. None of these have been grown in pure culture.

Answer 61

hot environments

Question 62

Thaumarchaeotes oxidize __________ and may play an important role in the nitrogen cycle.

Answer 62

ammonia (NH3)

Question 63

Lokiarchaeotes were discovered in 2015 by sequencing environmental samples from a hydrothermal vent. They are very similar, and the closest known prokaryotic relative of _____________.

Answer 63

eukaryotes

Question 64

Which firmicutes produce endospores?

Answer 64

Bacillus and Clostridium