Answer parts a through VV e) The simplest technique for isolating bacteria in gr
ID: 90840 • Letter: A
Question
Answer parts a through VV
e)
The simplest technique for isolating bacteria in growth media is referred to as the
f)
Bacteria may be stored
g)
In the growth curve of a bacteria population, the bacteria are rapidly increasing in number in the
h)
During which phase of growth are bacteria most susceptible to antibiotics?
i)
When doing experiments with bacteria
j)
During which phase of the bacterial growth curve does the total number of viable cells decline?
k)
The lag phase of the bacterial growth curve is marked by
l)
During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions?
m)
In a rapidly multiplying bacterial population, cell numbers increase
n)
Generally the proteins of thermophiles
o)
A hot tub (approx. 104 deg. F or 40 deg. C) would most likely contain
p)
The optimal temperature for most human pathogens might be expected to range from
q)
Mycobacterium leprae is typically found infecting the ears, toes and fingers of its host due to its
r)
Organisms that require gaseous oxygen for metabolism are referred to as
s)
Organisms that are indifferent to the presence of oxygen and do not use it are
t)
Shake tubes are used to determine the
u)
The optimum pH for growth of most species of bacteria is
v)
High concentrations of salt and sugar in foods
w)
Small organic molecules that must be provided to bacteria in order for them to grow are called
x)
Organisms that use organic molecules as their source of carbon are called
y)
Organisms that use CO2 as their source of carbon are called
z)
Chemoheterotrophs
A)
Medically important bacteria are often
B)
Products which limit pH changes are often incorporated into media and are referred to as
C)
A medium that inhibits the growth of organisms other than the one being sought is termed a(n)
D)
It is assumed that every colony observed on a streak plate arose from a single bacterium.
E)
In microbiology, growth usually refers to an increase in size of the bacteria.
F)
There are 5 stages of growth in an open system of culture.
G)
A single bacterial cell may multiply to form a visible colony.
H)
Freezing is an effective means of destroying bacteria.
I)
Lister developed his ideas on prevention of infection during medical procedures after studying the work of
J)
One of the first chemicals used by Lister to prevent surgical infections was
K)
The process of killing or removing all of the microorganisms in or on a material is termed
L)
A sterile item is free of viable
2-20-2013
M)
A suffix used to describe a killing action would be
N)
Pasteurization
O)
Plain soap is very effective in controlling spread of microorganisms because it is
P)
Nosocomial infections
Q)
To reduce or eliminate disease/spoilage causing organisms, food is often subjected to
R)
Microbial death rates may be affected by
S)
Moist heat kills microorganisms by
T)
Boiling is not reliable for sterilization because
U)
Which are essentially equivalent treatments?
V)
Which of the following is not a sterilization method?
W)
The autoclave treatment may be monitored by
X)
Commercial canning processes
Y)
Generally, membrane filters are not used to remove
Z)
Gamma irradiation
AA)
Ultraviolet radiation at the bactericidal wavelength destroy bacteria by
BB)
Microwaves do not kill organisms directly but kill by
CC)
Alcohols are not reliably effective at destroying
DD)
Glutaraldehyde
EE)
Chlorhexidine
FF)
Ethylene oxide is gas that
GG)
Which is true of iodine?
HH)
Which of the following is true of hydrogen peroxide?
II)
Phenolics
JJ)
Quaternary ammonium compounds are
KK)
Silver sulfadiazine, a combination of silver and a sulfa drug, is used to
LL)
Prions and viroids are easily destroyed by common sterilization procedures.
MM)
Upon heat treatment, bacteria die at a constant proportion.
NN)
The more bacteria one starts with, the longer it will take to kill them all.
OO)
Heat treatment is an effective method for sterilization or disinfection of all materials.
PP)
Boiling is very effective at removing most common waterborne pathogens.
QQ)
Dry heat takes a much shorter time to sterilize material than wet heat.
RR)
Hydrogen peroxide may be used as a sterilant on living tissue.
SS)
Organic acids, such as benzoic acid, are often added to foods to prevent microbial growth.
TT)
Which of the following organisms are resistant to destruction by typical control methods?
UU)
A common environmental organism that may even grow in certain chemical disinfectants is
VV)
Upon treatment with heat or chemicals, bacteria will
pour plate method.Explanation / Answer
Ans-(e)- Streak plate method
Ans-(f) - bacteria can be in glycerol stock at -80 degree centi. for longer period of time
Ans-(g) - exponantial (log) phase
Ans-(h) - exponantial (log) phase
Ans-(i) it is best to use colonies from the bacteria having same stage of growth colonies.
Ans -(j) total number of cells decline in death phase
Ans- (k)- metabolically active phase
Ans-(l)- late log phase
Ans-(m)-logarithmically
Ans-(n) Generally the proteins of thermophiles- resist denaturation
Ans-(o) A hot tub (approx. 104 deg. F or 40 deg. C) would most likely contain-mesophiles
Ans-(p) The optimal temperature for most human pathogens might be expected to range from-(35-40°C)
Ans-(q) Mycobacterium leprae is typically found infecting the ears, toes and fingers of its host due to its- need for cooler temperatures
Ans-(r) Organisms that require gaseous oxygen for metabolism are referred to as- obligate aerobes
Ans-(s) Organisms that are indifferent to the presence of oxygen and do not use it are- aerotolerant anaerobes
Ans-(t) Shake tubes are used to determine the- oxygen requirements for bacterial growth
Ans-(u) The optimum pH for growth of most species of bacteria is- pH-7
Ans-(v) High concentrations of salt and sugar in foods- are useful in preserving the food AND tend to draw water out of a cell or dehydrarate the cell
Ans-(w) Small organic molecules that must be provided to bacteria in order for them to grow are called- growth factors
Ans-(x) Organisms that use organic molecules as their source of carbon are called- heterotrophs
Ans-(y) Organisms that use CO2 as their source of carbon are called- autotrophs
Ans-(z) Chemoheterotrophs- use pre-formed organic molecules as a carbon source AND as an energy source