Chapter 27

Question 1

the most common organisms on earth are ___. They are divided into 2 domains which are ___ and ___.
most are very ___ and have a ___.

Answer 1

• prokaryotes
• bacteria, archaea
• small, cell wall

Question 2

most bacteria have cell walls of ___, which consists of sugars and proteins

Answer 2

peptidoglycan

Question 3

gram-positive bacteria ___

Answer 3

take violet/purple colored stain

Question 4

gram-negative bacteria ___

Answer 4

the violet stain washes out of these (pink)

-these bacteria have an outer membrane covering the cell wall

Question 5

___ pathogenic bacteria are more dangerous than ___ bacteria.

Answer 5

• gram-negative

- gram-positive

Question 6

___ pathogens often have toxins in their outer membrane and are more resistant to antibiotics than are ___ pathogens.

Answer 6

• gram-negative

- gram-positive

Question 7

many prokaryotes have a sticky protective coating called a ___

Answer 7

capsule

Question 8

• cocci (coccus):
• bacilli (bacillus):
• spirochetes and spirilla:
• vibrio:

Answer 8

• spherical shaped
• rod shaped
• helical, corkscrew shaped
• comma shaped

Question 9

cocci occurring in pairs

Answer 9

diplococci

Question 10

cocci occurring in chains

Answer 10

streptococci

Question 11

cocci occurring in clusters

Answer 11

staphylococci

Question 12

filament shaped and used for locomotion

Answer 12

flagella

Question 13

rigid cylindrical rods used to anchor prokaryotes to food sources and for conjugation

Answer 13

pili

Question 14

shorter and more numerous than pili

Answer 14

fimbriae

Question 15

the genome (the genes) of prokaryotes, on average, have ___ as much DNA as eukaryotes.

Answer 15

one thousandth

Question 16

the genome of a prokaryote is in the form of a ___, the eukaryote genome is ___.

Answer 16

• ring

- linear

Question 17

prokaryotes reproduce through ___, a form of cell division

Answer 17

binary fission

Question 18

binary fission is a type of ___

Answer 18

asexual reproduction

Question 19

3 forms of prokaryote genetic recombination:

Answer 19

• transformation
• transduction
• conjugation

Question 20

taking up genes from their surroundings

Answer 20

transformation

Question 21

transfer of genes between prokaryotes by viruses

Answer 21

transduction

Question 22

transfer of genes from one prokaryote to another. small rings of DNA called plasmids are transferred during this.

Answer 22

conjugation

Question 23

some prokaryotes can form into very tough ___ that can allow them to withstand extreme conditions.

Answer 23

endospores

Question 24

___ are food-filled cells produce by some cyanobacteria. they can withstand stressful conditions such as cold weather.

Answer 24

akinetes

Question 25

use light as energy

Answer 25

phototrophs

Question 26

obtain energy from chemicals in their environment

Answer 26

chemotrophs

Question 27

require only CO2 as a carbon source

Answer 27

autotrophs

Question 28

require organic molecules as a carbon source

Answer 28

heterotrophs

Question 29

- use light as an energy source and CO2 as a carbon source - prokaryotes - eukaryotes

Answer 29

- photoautotrophs - cyanobacteria - plants and algae

Question 30

use inorganic chemicals as an energy source and CO2 as a source of carbon -certain prokaryotes only

Answer 30

chemoautotrophs

Question 31

use light as an energy source and organic molecules as a carbon source -certain prokaryotes only

Answer 31

photoheterotrophs

Question 32

use organic molecules as energy source and a source of carbon - many prokaryotes - many eukaryotes including animals, fungi, many protists, and a few plants

Answer 32

chemoheterotrophs

Question 33

obligate aerobes: facultative anaerobes: obligate anaerobes:

Answer 33

- require oxygen - will use oxygen if available but can live without oxygen - can not live with oxygen present

Question 34

the ___ tend to inhabit extreme environments, although non-extreme forms have now been found

Answer 34

archaea

Question 35

most named prokaryotes are ___

Answer 35

bacteria

Question 36

the three main groups of extremophile archaea are:

Answer 36

methanogens, extreme halophiles, and extreme thermophiles

Question 37

live in anaerobic conditions such as in marshes and garbage dumps. produce methane

Answer 37

methanogens

Question 38

live in very salty places

Answer 38

extreme halophiles

Question 39

live under very high temperatures

Answer 39

extreme thermophiles

Question 40

many prokaryotes are ___, they live in direct contact with other species. The larger of the two species is called the ___.

Answer 40

symbiotic | host

Question 41

3 forms of symbiosis:

Answer 41

mutualism, commensalism, and parasitism

Question 42

both symbionts benefit

Answer 42

mutualism

Question 43

one symbiont benefits, the other symbiont is neither helped nor harmed

Answer 43

commensalism

Question 44

the parasite benefits, the host is harmed

Answer 44

parasitism

Question 45

there would be no other life without prokaryotes. they are very important for ___.

Answer 45

-cycling nutrients through the ecosystem

Question 46

the prokaryotes are important ___, they can break down organic materials in dead organisms

Answer 46

decomposers

Question 47

certain species of bacteria can "fix" atmospheric nitrogen into a form that can be used by other organisms

Answer 47

nitrogen fixation

Question 48

consist of a nucleic acid (DNA or RNA) covered with a coat of protein. they take over a host cell and force the cell to make copies until the host cell bursts open releasing new viruses

Answer 48

virus

Question 49

viruses that infect bacteria

Answer 49

bacteriophages

Question 50

tiny strands or circles of RNA with no protein coat | -cause plant diseases

Answer 50

viroids

Question 51

an alternate form of a protein that can change unaltered forms of the protein in the nervous system of animals -fatal

Answer 51

prions

Question 52

___ in humans are caused by prions | ___ in sheep

Answer 52

- Kuru and Creutzfeld-Jakob disease (CJD) - Scrapie - Bovine spongiform encephalopathy (BSE) “Mad Cow Disease” - BSE and CJD are probably linked