Growth and Nutrition of Bacteria
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An organism is
completely dependent on atmospheric O2 for growth. This organism is__________
a. Facultative
anaerobe
b. Osmotolerant
c. Obligate aerobe
d. Acidophile
Autotrophic
bacteria are those which__________
a. Make their own food
b. Form a
long chain glycocalyx
c. Are
highly susceptible to penicillin
d. Produce
a blue-green pigment
All organisms
require at least small amounts of carbondioxide, However, some can use CO2 as
their sole source of carbon. Such organisms are termed as__________
a. Phototrophs
b. Autotrophs
c. Photo-organotrophs
d. Chemotrophs
A culture broth
tube was very turbid at the bottom of the tube but clear at the top of the tube
indicating that the__________
a. Broth is
sterile
b. Organism cannot produce
superoxide dismutase and/or catalase
c. Organism
can tolerate oxygen
d. Organism
should be grown in an anaerobic chamber
A culture broth
tube was very turbid at the surface but clear throughout the rest of the tube
indicating that the__________
a. Organism
cannot tolerate oxygen
b. Organism are aerobes
c. Organism
should be grown in an anaerobic chamber
d. Organism
cannot produce superoxide dismutase and/or catalase
A synergistic
effect is observed when__________
a. One
organism produces a growth factor utilized by another
b. One
organism removes an inhibitory substance for another
c. Microbial
alteration of pH, aw, Eh favours the growth of another
d. All of the above
Antimicrobial
constituents for the microbial growth in foods are__________
a. Extrinsic
factor
b. Intrinsic factor
c. Both (a)
and (b)
d. None of
these
A spore differs
from an actively replicating bacterium in that the spore__________
a. Is able
to withstand more extreme conditions than the replicating cell
b. Is
metabolically inactive
c. Is
produced during a process involving asymmetric division
d. All of the above
An organism has an
optimal growth rate when the hydrogen ion concentration is very high. This
organism is__________
a. Osmotolerant
b. Neutrophile
c. Acidophile
d. Aerotolerant
anaerobe
An organism that
expends energy to grow in a habitat with a low water activity in order to
maintain internal solute concentrations to retain water is__________
a. Acidophile
b. Osmotolerant
c. Aerotolerant
anaerobe
d. Alkalophile
A microbe, which
grows at temperatures above 95° C is most likely to be__________
a. An archaean
b. A fungus
c. A
protozoan
d. None of
these
Bacteria of genus
Nitrosomonas use __________ as their electron source.
a. H2S
b. Ammonia
c. Light
d. Succinate
Bacteria and fungi
multiply best__________
a. Below
16°C
b. Above
38°C
c. Between 16-38°C
d. None of
these
During exponential
growth, the growth rate is__________
a. Reciprocal of generation time
b. Number
of generations per unit time
c. Both (a)
and (b)
d. None of
these
Exponential phase
of growth curve of bacteria is of limited duration because of__________
a. Rise in
cell density
b. Exhaustion
of nutrients
c. Accumulation
of toxic metabolites
d. All of these
Generation time is__________
a. Time
required for the initial adjustment
b. Obtained
by expression t/n, where t = time interval, n = number of generation
c. Time
required for the population to double
d. Both (a) and (c)
Generation time of
Escherichia coli is__________
a. 20 minutes
b. 20 hours
c. 20 days
d. 200
hours
In the exponential
phase, the cells and cell mass__________
a. Are
constant
b. First
increases then decreases
c. Decreases
d. Double at a constant rate
Implicit factors__________
a. Depend
on developing microflora
b. Can be
synergistic
c. None of
the above
d. Both (a) and (b)
Lag phase is also
known as__________
a. Transitional
period
b. Period of initial adjustment
c. Generation
time
d. None of
these
Microaerophilic
bacteria are those which require__________
a. 21 % oxygen
for growth
b. Oxygen
for activation of enzymes
c. Low levels of oxygen for growth
(lesser than O2 present in atmosphere)
d. None of
the above
Nutrient content
and biological structures are considered as__________
a. Processing
factor
b. Implicit
factor for microbial growth
c. Intrinsic factor for microbial
growth
d. None of
the above
Organisms such as
lactobacilli that have elaborate requirements for specific nutrients i.e.
vitamins and other growth promoting substances, are generally called as__________
a. Photo-organotrophs
b. Fastidious hetrotrophs
c. Chemo-lithotrophs
d. Chemotrophs
Organisms, using
organic compounds as electron donors are called__________
a. Organotrophs
b. Lithotrophs
c. Chemotrophs
d. Phototrophs
Pseudomonas
pseudoflava can grow as__________
a. Chemo-organotrophs
b. Chemo-lithotrophs
c. Both (a) and (b)
d. None of
these
Postgates assay
technique is useful in determining if a cell is viable even though it is__________
a. Too
small to see
b. Incapable of cell division
c. A
thermophile
d. An
obligate aerobe
Quantitative
measurement of bacterial growth can be carried out by measuring__________
a. Cell
mass
b. Cell
count
c. Cell
activity
a. All of these
Some organisms can
use reduced inorganic compounds as electron donors and are termed as__________
a. Photo-organotrophs
b. Lithotrophs
c. Chemotrophs
d. Phototrophs
Starvation proteins
are produced by a culture during which of the following segments of the growth
curve?
a. Lag
phase
b. Stationary phase
c. Exponential
phase
d. Death
phase
The cell
reproduction in bacteria may occur by__________
a. Fragmentation
b. Budding
c. Binary
fission
d. All of these
The reproduction by
budding occur in__________
a. Rhodopseudomonas
acidophila
b. Hyphomicrobium
vulgare
c. Bacillus
subtilis
d. Both (a) and (b)
The total biomass
of an organism will be determined by the nutrient present in the lowest
concentration relative to the organism's requirements is a statement of__________
a. Shelford's
law of tolerance
b. Liebig's law of the minimum
c. Heisenberg's
principle of uncertainty
d. Quorum
sensing
The growth is
normally expressed as __________ in turbidimetric measurement
a. Optical density
b. cfu/ml
c. mg N2
/ml
d. cells
per ml
The organism which
obtain their energy from chemicals are designated as__________
a. Prototrophs
b. Organotrophs
c. Autotrophs
d. Chemotrophs
The equation used
to obtain bacterial population by binary fission is__________
a. N = No2n
b. log(N/No)
= nlog 2
c. log N/No
= (0.3010) n
d. All of these
The average size of
cells during the exponential phase of growth is__________
a. Lesser than the lag phase
b. Greater
than the lag phase
c. Equal to
the lag phase
d. None of
these
The organism which
grows best above 45°C are called__________
a. Psychrophilic
b. Thermophilic
c. Mesosphilic
d. Any of
these
The combination of
low levels of NaCl, NaNO3 (sodium nitrate), and slightly acid pH can prevent
multiplication and toxin formation of__________
a. Salmonella
b. C.
botulinum
c. S.
aureus
d. All of these
The generation time
of a culture that produces two generations per hour is__________
a. Lesser
than that produces three generations per hour
b. Equal to
that produces three generations per hour
c. Greater than that produces three
generations per hour
d. None of
the above
The straightforward
method of binary fission explains how bacteria__________
a. Reproduce
b. Move
c. Evolve
d. Grow in
nutrient agar
The term
facultative anaerobe refers to an organism that__________
a. Doesn't
use oxygen but tolerates it
b. Uses oxygen when present or grows
without oxygen when absent
c. Requires
less oxygen than is present in air
d. Is
killed by oxygen
The microorganisms
that grow best in a low-oxygen environment is called a (n) __________
a. Anaerobe
b. Aerobe
c. Microaerophile
d. Facultative
The period between
inoculation of bacteria in a culture medium and beginning of multiplication is
known as__________
a. Stationary
phase
b. Lag phase
c. Decline
phase
d. Log
phase
The term
aerotolerant anaerobe refers to an organism that__________
a. Is
killed by oxygen
b. Doesn't use oxygen but can grow
in the presence of oxygen
c. Prefers
to grow without oxygen
d. Requires
less oxygen than is present in air
The term obligate
anaerobe refers to an organism that__________
a. Is killed by oxygen
b. Doesn't
use oxygen but tolerates it
c. Prefers
to grow without oxygen
d. Uses
oxygen when present or grows without oxygen when oxygen is absent
The fragmentation
occurs in__________
a. Bacillus
subtilis
b. Streptomyces
species
c. Nocardia species
d. None of
these
The ability of
Vibrio fischeri to produce bioluminescence chemicals only when a certain
population density has been reached is an example of__________
a. Shelford's
law of tolerance
b. Liebig's
law of the minimum
c. Heisenberg's
principle of uncertainty
d. Quorum sensing
Which of the
following is not the characteristic of a growth curve?
a. Shows
development of microbial population under relatively stable environmental
conditions
b. Each growth curve consists of four
distinct phases
c. Plotted
with logarithmic numbers
d. Graphs
numbers of microbes versus time
Which of the
following is used to grow bacterial cultures continuously?
a. Hemostat
b. Chemostat
c. Coulter
Counter
d. Petroff-Hausser
chamber
Which of the following
organisms typically get their carbon for biosynthesis from carbon dioxide?
a. Glucose-fermenting
bacteria (fermentation)
b. Anaerobic,
glucose-respiring bacteria (anaerobic respiration)
c. Ammonia-oxidizing bacteria
(chemolithotrophic bacteria)
d. Aerobic,
glucose-respiring bacteria (aerobic respiration)
Which of the
following procedures uses a photocell to measure absorbance of a culture to
regulate the flow of culture media?
a. Coulter
Counter
b. Petroff-Hausser
chamber
c. Hemostat
d. Trubidostat
Which of the
following has more tolerance for acidic pH (lower pH)?
a. Yeast and moulds
b. Bacteria
c. E. coli
d. None of
these
Which of the
following is the suitable temperature range for mesophiles?
a. 20-30°C
b. >40°C
c. 25-40°C
d. None of
these
What is the primary
source of food for marine life?
a. Phytoplankton
b. Grass
c. Zooplankton
d. Sea weed
What are the
extrinsic factors for the microbial growth?
a. Storage
temperature
b. Humidity
c. Composition
of gas phase
d. All of these
Which of the
following organisms typically get their carbon for biosynthesis from organic
compounds?
a. Ammonia-oxidizing
bacteria (chemolithotrophic bacteria)
b. Aerobic, glucose-respiring
bacteria (aerobic respiration)
c. Photosynthetic
cyanobacteria (phototrophic metabolism)
d. None of
the above
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