WorksheetsBacteriology quizz
Total questions: 30
Worksheet time: 15mins
Microorganisms that can be found thriving in icy-cold climates would be considered....
barophiles
thermophiles
mesophiles
psychrophiles
bibliophil
Which phase in a population growth curve is associated with no increase or decrease in population?
lag phase
logarithmic phase
stationary phase
death phase
which microbe would you most likely find in large number in an extremely hypertonic salty
Mycobacterium
Bacillus
Staphylococcus
Halobacterium salinarum
Salmonella
which term best discribes an organism that can't exist in the presence of oxygen
obligate aerobe
facultative aerobe
obligate anaerobe
falculatative anaerobe
Microaerophile
Time required by the cell to undergo binary fission is called the:
exponential growth rate
growth curve
generation time
lag period
stationary phase
A visible cluster of cells that have arisen from one parent cell growing on the surface of a growth medium is called:
bacterium
inoculum
cells
colony
coccus
The stage in the population growth curve with the highest rate of cell division is called the ......................
stationary
lag phase
exponential phase
death phase
which category of microbes would you expect to grow best on or in your body?
pyschrophiles
mesophiles
thermophiles
hyperthermophilies
An obligate halophiles requires high
pH
temperature
salt
pressure
Psychrophiles would be expected to grow
in hot spring
on the human body
at refrigenation temperature
at low pH
The organism which grows best above 45 degrees are called
psychrophillic
mesosphilic
thermophilic
any of these
The growth is normally expressed as in turbidimetric measurement
cells per ml
cfu/ml
optical density
mg N2/ml
An organism that expands energy to grow in a habitat with a low water activity in order to maintain internal solute concentration to retain water is
osmotolerant
acidophile
aerotolerant anaerobic
alkalophile
The equation used to obtain bacterial population by binary fission is
N=No2n
log N/No = (0.3010)n
log (N/No) = nlog2
All of the above
An organism has an optimal growth rate when the hydrogen ion concentration is very high. This organism is
osmotolerant
acidophile
nuetrophile
aerotolerant anaerobe
Which of the following procedures uses a photocell to measure absorbance of a culture to regulate the flow of culture media
Coulter counter
Hemostat
petroff-hauseer chamber
Turbidostat
Starvation proteins are produced by culture during which of the following segments of the growth curves
Lag phase
Exponential phase
Stationary phase
Death phase
Which of the following has more tolerance for acidic pH (lower pH)?
Yeast and moulds
Bacteria
E.coli
None of the above
The ability of Vibro fischeri to produce bioluminescence chemicals only when a certain population density has been reached is an example of
Liebig's law of the minimum
Shelford's law of tolerance
qourum sensing
Heisenberg's principle of uncertainty
The term facultative anaerobic refers to an organism that
doesn't use oxygen but tolerates it
it killed by oxygen
uses oxygen when present or grows without oxygen when absent
requires less oxygen that is present in air
Microoranism that grow best in a low-oxygen environment is called an (n)
aerobe
anaerobe
falcultative
microaerophile
Exponential phase of growth curve of bacteria is of limited duration because of
rise in cell density
accumulation of toxic metabolites
exhaustion of nutrients
all of the above
The generation time of a culture that produces two generations per hour is
greater than that produce three generations per hour
lesser than that produces three generations per hour
equal to that produces three generation per hour
none of the above
An organism is completely dependent on atmospheric O2 for growth. This organism is
osmotolerant
acidophile
facultative anaerobe
obligate aerobe
Microaerophilic bacteria are those which require
21% oxygen for growth
low levels of oxygen for growth (lesser than O2 present in atmosphere)
oxygen for activation of enzymes
none of the above
The period between inoculation of bacteria in a culture medium and beginning of multiplication is known as
stationary phase
log phase
lag phase
decline phase
The term obligate anaerobe refers to an organism that
doesn't use oxygen but tolerate it
is killed by oxygen
uses oxygen when present or grows with oxygen when oxygen is absent
prefers to grow without oxygen
Generation time of Escherichia coli is
20 minutes
20 hours
20 days
200 hours
What is the function of the Z ring in binary fission?
It controls the replication of DNA
It forms a contraction ring at the septum
It separates the newly synthesized DNA molecules
It mediates the addition of new peptidoglycan subunits
Which of the following reason jams and dried meats often do not require refrigeration to prevent spoilage?
Low pH
Toxic alkaline chemicals
naturally occurring antibiotics
low water activity
