CH 20

Question 1

_______ are aggregates of bacteria

that secrete _____________

and _______ _______

(against antibiotics, disinfectants, etc).

ex: _______ _______

Answer 1

Biofilms are aggregates of bacteria

that secrete polysaccharide

and provide defense

(against antibiotics, disinfectants, etc).

ex: dental plaque

Question 2

Lis the 3 bacterial shapes:

Answer 2

spherical (cocci),

rod-like (bacilli),

corkscrew (spirilla)

Question 3

Which prokaryote has peptidoglycan in cell walls?

Answer 3

bacteria

Question 4

___ ________ account for the creation

of new types of bacteria.

Answer 4

DNA Mutations account for the creation

of new types of bacteria.

Question 5

_______-_______ _______

capture _______ ___ (N₂) from soil

and convert it to _________ (NH₄⁺),

making it accessible to plants.

Answer 5

Nitrogen-fixing bacteria

capture nitrogen gas (N₂) from soil

and convert it to ammonium (NH₄⁺),

making it accessible to plants.

Question 6

Viruses replicate by:

______ a host cell,

where ___/___ causes the cell

to reproduce ______ __________,

which ______ ______ into viruses,

which then _____ ____ host cell.

Answer 6

Viruses replicate by:

entering a host cell,

where DNA/RNA causes the cell

to reproduce viral components,

which assemble rapidly into viruses,

which then burst from host cell.

Question 7

A bacterium can survive long periods of ________

by producing an ________ (consisting of

________ material, ________, & a protective coating),

which doesn’t ________, just remains stable;

when ________ ________ arise

(i.e. contact with water), it resumes life.

Answer 7

A bacterium can survive long periods of dessication

by producing an endospore (consisting of

genetic material, enzymes, & a protective coating),

which doesn’t metabolize, just remains stable;

when favorable conditions arise

(i.e. contact with water), it resumes life.

Question 8

What are 3 roles of bacteria in ecosystems?

Answer 8

nitrogen fixation

recycling organics

bioremediation

Question 9

How many known clades are in the Bacteria domain?

Answer 9

30, including:

cyanobacteria, firmicutes, proteobacteria

Question 10

How does the flagellum of a prokaryote move?

Answer 10

wheel-and-axle rotation

Question 11

What are 5 types of extreme environments

that can bacteria can live in?

Answer 11

temps - boiling / freezing, e.g. antarctica / hot springs

time - stable, >250million years

pressure - e.g. bottom of sea floor

chemical - e.g. high salt desiccation - e.g. anthrax spores as bioterror agent

acidic or alkaline - vinegar/ammonia

Question 12

Viruses are ________ and

attack only ________ host cell(s).

Answer 12

Viruses are specialized and

attack only specific host cell(s).

Question 13

Ways bacteria provide benefits to humans:

make _______,

_____ _______ from dead organisms for reuse,

______________ (e.g., oil spill clean up),

_______ _______ in gut & vagina,

_________ of _____ (cheese, yogurt);

in animals, they break down _______.

Answer 13

Ways bacteria provide benefits to humans:

make vitamins,

free nutrients from dead organisms for reuse,

bioremediation (e.g., oil spill clean up),

maintain balance in gut & vagina,

production of foods (cheese, yogurt);

in animals, they break down cellulose.

Question 14

Viruses are composed of:

___/___ - hijacks host cell for _________

______ ___ - enables entry into ___ ___

Answer 14

Viruses are composed of:

DNA/RNA - hijacks host cell for reproduction

Protein coat - enables entry into host cell

Question 15

Bacteria & Archaea are both

________, ________, and ____ (micrometers).

Answer 15

Bacteria & Archaea are both

prokaryotic, unicellular, and small (micrometers).

Question 16

____________ are blue-green ‘algae’

that ____________ via ________ in membranes.

Answer 16

Cyanobacteria are blue-green ‘algae’

that photosynthesize via chlorophyl in membranes.

Question 17

____-________ bacteria lack lipopolysaccharides.

Answer 17

Gram-positive bacteria lack lipopolysaccharides.

Question 18

_______ are infectious particles composed of only short ___ (no protective coating) that attack ______.

Answer 18

Viroids are infectious particles composed of only short RNA (no protective coating) that attack plants.

Question 19

Bacteria exchange genetic information via the __________ ______ (or, sex _____).

Answer 19

Bacteria exchange genetic information via the cytoplasmic bridge (or, sex pilus).

Question 20

Prokaryotes are classified using:

________ sequences, ______, means of ________,

________, _______ requirements, _______ appearance,

and _____-________ characteristics.

Answer 20

Prokaryotes are classified using:

nucleotide sequences, shape, means of locomotion,

pigments, nutrient requirements, colony appearance,

and gram-staining characteristics.

Question 21

types of genetic material in viruses

Answer 21

DNA or RNA, single or double stranded (nucleic acids)

Question 22

______ are misfolded proteins (PrP)

in the membranes of ______;

when ingested,

they cause ______ PrP to become misfolded,

leading to ____ damage & death.

examples: ____ - via cannibalism, Creutzfeldt-______ Disease, ______ (in sheep), ____ ____ disease

Answer 22

Prions are misfolded proteins (PrP)

in the membranes of neurons;

when ingested,

they cause benign PrP to become misfolded,

leading to CNS damage & death.

examples: Kuru - via cannibalism, Creutzfeldt-Jacob Disease, Scrapie (in sheep), mad cow disease

Question 23

What does sulfur bacteria use instead of water for photosynthesis?

Answer 23

hydrogen sulfide (H₂S)

Question 24

There are ___ known clades in Archaea, including c____________ & e____________.

Answer 24

There are 5 known clades in Archaea, including crenarchaeota & euryarchaeota.

Question 25

_____________ are viruses that infect bacteria.

Answer 25

Bacteriophages are viruses that infect bacteria.

Question 26

________ are small, circular DNA molecules

that carry genes from donor to recipient

in prokaryote ________.

Answer 26

Plasmids are small, circular DNA molecules

that carry genes from donor to recipient

in prokaryote conjugation.

Question 27

examples of diseases caused by bacteria

Answer 27

tetanus, botulism, bubonic plague, lyme disease, c. diff, TB, gonorrhea, syphilis, cholera, strep, e. coli, sepsis

Question 28

Are viruses living organisms?

Why or why not?

Answer 28

No -

they do not have a cell membrane,

and they do not independently reproduce or grow

Question 29

Are viruses considered parasites?

Why or why not?

Answer 29

Yes -

bc they live in/on host,

cause harm to that host,

and can’t reproduce or grow independently of a host

Question 30

Bacteria obtain energy & nutrients from

______ and ______ ______

(even __________ ones).

Answer 30

Bacteria obtain energy & nutrients from

organic and inorganic compounds

(even poisonous ones).

Question 31

Metabolism of prokaryotes:

some ________ (tetanus)

some can switch ___/_______ (e. coli)

________ compounds

________ compounds (petroleum)

________ molecules (hydrogen, sulfur)

____________ (cyanobacteria, sulfur bacteria)

Answer 31

Metabolism of prokaryotes:

some anaerobic (tetanus)

some can switch an/aerobic (e. coli)

organic compounds

poisonous compounds (petroleum)

inorganic molecules (hydrogen, sulfur)

photosynthesis (cyanobacteria, sulfur bacteria)

Question 32

____________ is the practice

of manipulating conditions

to stimulate breakdown of pollutants

by living organisms.

Answer 32

Bioremediation is the practice

of manipulating conditions

to stimulate breakdown of pollutants

by living organisms.

Question 33

Bacteria reproduce asexually via

_______ _______ (_______ _______, rapidly).

Answer 33

Bacteria reproduce asexually via

binary fission (identical copies, rapidly).

Question 34

Bacteria & Archaea differ in the biochemical structures of:

cell walls (____________ - bacteria only)

______ membranes

_________

____ polymerases

Answer 34

Bacteria & Archaea differ in the biochemical structures of:

cell walls (peptidoglycan - bacteria only)

plasma membranes

ribosomes

RNA polymerases

Question 35

Bacteria reproduce sexually via __________:

the transfer of ________ ________ (donor to recipient)

across a ________ ________ or sex pilus.

Answer 35

Bacteria reproduce sexually via conjugation:

the transfer of genetic material (donor to recipient)

across a cytoplasmic bridge or sex pilus.

Question 36

____________ is the process by which

facultative anaerobic bacteria survive

when there is no oxygen available.

Answer 36

Fermentation is the process by which

facultative anaerobic bacteria survive

when there is no oxygen available.

Question 37

Gram-________ bacteria,

which are resilient to ________,

____ lipopolysaccharides.

Answer 37

Gram-negative bacteria,

which are resilient to antibiotics,

have lipopolysaccharides.

Question 38

__________ were earth’s first organisms,

and the only life form for more than _______ years.

Answer 38

Prokaryotes were earth’s first organisms,

and the only life form for more than 1.5 million years.

Question 39

_________ differ from other viruses in that

they use ___ as genetic material,

and ______ _________ transcribes its RNA into DNA

which is inserted into the ___ of the host cell.

Answer 39

Retroviruses differ from other viruses in that

they use RNA as genetic material,

and reverse transcriptase transcribes its RNA into DNA

which is inserted into the DNA of the host cell.

Question 40

Which domains contain organisms that photosynthesize?

Answer 40

Bacteria & Eukarya