ch9

Question 1

The replication of DNA starts at a location on the circular chromosome called

Answer 1

origin of replication

Question 2

Process of cytokinesis and cell division is directed by a protein called

Answer 2

FtsZ

Question 3

Divisome function

Answer 3

produce peptidoglycan wall and build a septum to divide daughter cells

Question 4

lag phase

Answer 4

no increase in number of living cells

Question 5

log phase

Answer 5

exponential increase in living cells

Question 6

stationary phase

Answer 6

plateau in number of living cells, rate of division and death is equal

Question 7

death/decline phase

Answer 7

exponential decrease in living cells

Question 8

beginning of growth curve

Answer 8

inoculum

Question 9

inoculum is added to a fresh

Answer 9

culture medium

Question 10

sporulation and secondary metabolite productions are associated with what phase

Answer 10

stationary

Question 10

duration of lag phase depends on

Answer 10

1. species and genetic makeup
2. composition of medium
3. size of original inoculum

Question 11

secondary stain

Answer 11

stains if cytoplasmic membrane is damaged (dead)

Question 12

primary stain

Answer 12

stains both live and dead

Question 12

chemostat

Answer 12

maintain a continuous culture with nutrients supplied

Question 13

pH indicator that changes color from red to yellow when

Answer 13

lactose is fermented

Question 14

microorganisms grow mainly in

Answer 14

biofilms: complex ecosystems that form on a variety of environmental surfaces

Question 15

biofilms secrete an extracellular matrix called

Answer 15

extracellular polymeric substances

Question 16

free-floating microbial

Answer 16

planktonic

Question 17

cells in a biofilm coordinate their activities in response to environmental stimuli

Answer 17

quorum sensing

Question 18

quorum sensing enables microorganisms to detect cell density through release and binding of molecules called

Answer 18

autoinducers

Question 19

pathogens embedded within biofilms exhibit

Answer 19

a higher resistance to antibiotics than their free-floating counterparts

Question 20

reactive oxygen species (ROS)

Answer 20

unstable ions and molecules derived from partial reduction of oxygen

Question 21

Obligate aerobes

Answer 21

cant grow without abundant supply of oxygen

Question 22

Aerotolerant anaerobes

Answer 22

don’t use oxygen

Question 23

Facultative anaerobes

Answer 23

thrive in presence of oxygen

Question 24

Microaerophiles

Answer 24

require little oxygen

Question 24

Obligate anaerobes

Answer 24

killed by oxygen

Question 25

Anaerobic conditions are good for obligate anaerobes such as

Answer 25

Clostridium spp

Question 26

One major cause of health-acquired infections

Answer 26

C. difficile

Question 27

Clostridia responsible for serious infections

Answer 27

tetanus and gas gangrene

Question 28

catalase

Answer 28

converts hydrogen peroxide to water and oxygen

Question 28

3 enzymes that break down toxic byproducts

Answer 28

SOD, peroxidase, catalase

Question 29

obligate anaerobes lack

Answer 29

the 3 enzymes

Question 30

aerotolerant anaerobes have

Answer 30

SOD but no catalase

Question 30

Acidophiles pH

Answer 30

3

Question 31

Alkaliphiles pH

Answer 31

9

Question 31

barophiles

Answer 31

microorganisms that require high pressure for growth

Question 31

environmental conditions affecting growth

Answer 31

osmotic/barometric pressure
light

Question 32

Decrease in temperature causes

Answer 32

decrease in growth rate

Question 32

DNA sequences show a higher proportion of

Answer 32

G-C nitrogenous bases