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All the bacterial cells that result from the replication of a single original bacterial organism are said to be a
population.
pure culture.
lag culture.
mutant culture.

pure culture

The scientist that contributed most to the development of pure culture techniques was
Alexander Fleming.
Louis Pasteur.
Edward Jenner.
Robert Koch.

Robert Koch

The simplest technique for isolating bacteria in growth media is referred to as the
pour plate method.
streak plate method.
serial dilution method.
MPN method.

streak plate method

Prokaryotic cells divide by a process known as
conjugation.
mitosis.
binary fusion.
binary fission.

binary fission

In nature, bacteria
often grow in close association with many other kinds of organisms.
may remain in a prolonged exponential phase.
frequently synthesize structures such as slime layers.
may adhere to surfaces by means of pili and slime layers.
All of the choices are correct.

All of the choices are correct.

Biofilms
are a haphazard mixture of bacteria.
are a polysaccharide-encased community of microorganisms.
may enhance bioremediation efforts.
may protect organisms against harmful chemicals.
are a polysaccharide-encased community of microorganisms, may enhance bioremediation efforts AND may protect organisms against harmful chemicals.

are a polysaccharide-encased community of microorganisms, may enhance bioremediation efforts AND may protect organisms against harmful chemicals.

The simplest technique for isolating bacteria in growth media is referred to as the
pour plate method.
streak plate method.
serial dilution method.
MPN method.

streak plate method

Bacteria may be stored
on a slant in the refrigerator.
frozen in glycerol solution.
lyophilized.
in broth at 37°C.
on a slant in the refrigerator, frozen in glycerol solution AND lyophilized.

on a slant in the refrigerator, frozen in glycerol solution AND lyophilized.

In the growth curve of a bacteria population, the bacteria are rapidly increasing in number in the
lag phase.
exponential (log) phase.
stationary phase.
decline phase.
boomer phase.

exponential (log) phase

During which phase of growth are bacteria most susceptible to antibiotics?
lag
stationary
exponential (log)
decline

exponential (log)

During which phase of the bacterial growth curve does the total number of viable cells decline?
stationary
lag
exponential
death

death

The lag phase of the bacterial growth curve is marked by
a decrease in cell mass.
dormant, metabolically inactive cells.
metabolically active cells.
vigorously dividing cells.

metabolically active cells

Late log phase of the bacterial growth curve
is marked by the production of primary metabolites.
is marked by the production of secondary metabolites.
is a transition into the death phase.
shows a decline in cell numbers.

is marked by the production of secondary metabolites.

During which phase of the bacterial growth curve does a bacterial population become much more resistant to harmful conditions?
lag phase
exponential phase
stationary phase
late log phase

late log phase

In a rapidly multiplying bacterial population, cell numbers increase
arithmetically.
logarithmically.
linearly.
indirectly.

logarithmically

The speed of enzymatic reactions approximately doubles for each
5° C rise in temperature.
10° C rise in temperature.
20° C rise in temperature.
30° C rise in temperature.

10° C rise in temperature.

Generally the proteins of thermophiles
resist denaturation.
react more efficiently with DNA.
are easily denatured.
have a particular amino acid sequence that restricts bond formation.
are easily denatured AND have a particular amino acid sequence that restricts bond formation.

resist denaturation

A hot tub (approx. 104 deg. F or 40 deg. C) would most likely contain
psychrophiles.
partiers.
thermophiles.
mesophiles.

mesophiles

The optimal temperature for most human pathogens might be expected to range from
35-40°C.
20-45°C.
15-25°C.
93-98.6°C.

35-40°C.

Bacteria on fish caught in the Arctic Ocean would
be psychrophiles.
be mesophiles.
continue to grow while the fish is in the refrigerator.
not grow very well in the refrigerator.
be psychrophiles AND continue to grow while the fish is in the refrigerator.

be psychrophiles AND continue to grow while the fish is in the refrigerator.

Mycobacterium leprae is typically found infecting the ears, toes and fingers of its host due to its
requirement for well-oxygenated blood.
easy access to those parts.
need for cooler temperatures.
long incubation period.

need for cooler temperatures

Organisms that require gaseous oxygen for metabolism are referred to as
facultative aerobes.
obligate aerobes.
facultative anaerobes.
microaerophiles.

obligate aerobes

Which of the following is/are obligate aerobes?
Clostridium botulinum
Escherichia coli
Micrococcus luteus
Helicobacter pylori

Micrococcus luteus

Organisms that are indifferent to the presence of oxygen and do not use it are
aerotolerant anaerobes.
facultative anaerobes.
obligate aerobes.
microaerophiles.

aerotolerant anaerobes

The enzymes that deal with toxic oxygen-containing molecules is/are
glycolase.
superoxide dismutase.
catalase.
hydrogen peroxidase.
superoxide dismutase AND catalase.

superoxide dismutase AND catalase.

Shake tubes are used to determine the
pH requirements for bacterial growth.
temperature requirements for bacterial growth.
oxygen requirements for bacterial growth.
salt requirements for bacterial growth.

oxygen requirements for bacterial growth.

The optimum pH for growth of most species of bacteria is
pH 5.
pH 7.
pH 9.
pH 6.

pH 7

High concentrations of salt and sugar in foods
are useful in preserving the food.
tend to draw water out of a cell.
tend to force water into a cell, causing plasmolysis.
have no effect on water availability.
are useful in preserving the food AND tend to draw water out of a cell.

are useful in preserving the food AND tend to draw water out of a cell.

Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur may be considered
minor elements.
major elements.
neutral elements.
acidic elements.

major elements

Trace elements
include zinc, copper and manganese.
are required in large amounts.
may be needed for enzyme function.
are involved in maintaining pH in the cell.
include zinc, copper and manganese AND may be needed for enzyme function.

include zinc, copper and manganese AND may be needed for enzyme function.

Small organic molecules that must be provided to bacteria in order for them to grow are called
minerals.
growth factors.
water.
vitamins.

growth factors

The prefix photo- indicates that an organism will make use of _______ for energy purposes.
chemicals
organics
light
inorganics

light

Organisms that use organic molecules as their source of carbon are called
chemotrophs.
organoheterotrophs.
heterotrophs.
autotrophs.

heterotrophs

Organisms may derive energy from
sunlight.
metabolizing chemical compounds.
little tiny AAAAAAAAA batteries.
temperature gradients.
sunlight AND metabolizing chemical compounds.

sunlight AND metabolizing chemical compounds.

Organisms that use CO2 as their source of carbon are called
organotrophs.
heterotrophs.
autotrophs.
chemotrophs.

autotrophs

Chemoheterotrophs
use sunlight as an energy source.
use pre-formed organic molecules as a carbon source.
use pre-formed organic molecules as an energy source.
use inorganic chemicals as an energy source.
use pre-formed organic molecules as a carbon source AND as an energy source.

use pre-formed organic molecules as a carbon source AND as an energy source.

Peptone
refers to a hydrolysate of carbohydrates used in growth media.
refers to a hydrolysate of proteins used in growth media.
consists of a water extract of beef.
consists of a mix of monosaccharides and oligosaccharides.
refers to a hydrolysate of proteins used in growth media AND consists of a water extract of beef.

refers to a hydrolysate of proteins used in growth media.

Medically important bacteria are often
grown on agar containing blood.
grown at 37°C.
grown on agar containing chocolate.
grown at a pH of 5.
grown on agar containing blood AND grown at 37°C.

grown on agar containing blood AND grown at 37°C.

A medium that inhibits the growth of organisms other than the one being sought is termed a(n)
synthetic medium.
specific culture medium.
selective medium.
enrichment medium.

selective medium

MacConkey agar is
a selective agar.
a differential agar.
a selective and differential agar.
used to distinguish between bacteria by the type of hemolysis observed.

a selective and differential agar.

Candle jars are usually used to
store candles.
provide an atmosphere with CO2.
stimulate the growth of obligate anaerobes.
prevent the growth of obligate aerobes.
provide an atmosphere with CO2 AND stimulate the growth of obligate anaerobes.

provide an atmosphere with CO2.

In the cultivation of microaerophilic and anaerobic bacteria,
a(n) candle/anaerobe jar is sufficient.
atmospheric oxygen in a(n) candle/anaerobe jar is converted to water.
a catalyst is used that makes hydrogen and carbon dioxide in a(n) candle/anaerobe jar.
oxidizing agents are incorporated into the media that react with oxygen.

atmospheric oxygen in a(n) candle/anaerobe jar is converted to water.

Agar
is a useful nutrient source for most bacteria.
is a hydrolysate of proteins.
stays liquid through the typical range of incubation temperatures.
has chemical and physical properties that make it almost ideal for solidifying media.

has chemical and physical properties that make it almost ideal for solidifying media.

Agar replaced gelatin as the gelling (solidifying) agent for media because
agar is much cheaper.
much fewer bacteria can break down agar than gelatin.
agar is solid at body temperature.
gelatin became unavailable during World War II.
much fewer bacteria can break down agar than gelatin AND agar is solid at body temperature.

much fewer bacteria can break down agar than gelatin AND agar is solid at body temperature.

It is assumed that every colony observed on a streak plate arose from a single bacterium.
True
False

True

In microbiology, growth usually refers to an increase in size of the bacteria.
True
False

False

There are 5 stages of growth in an open system of culture.
True
False

False

Secondary metabolites may be antibiotics.
True
False

True

A single bacterial cell may multiply to form a visible colony.
True
False

True

Prokaryotes are the only organisms able to use atmospheric nitrogen as a nitrogen source.
True
False

True

Freezing is an effective means of destroying bacteria.
True
False

False

One would expect most strict anaerobic organisms to have superoxide dismutase.
True
False

False

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