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WorksheetsChapter 13
Total questions: 57
Worksheet time: 29mins
Staphylococcus aureus is a type of
Pathogenic spore
virus
bacteria
fungi
pathogenic fungi
MRSA is caused by
Streptococcus aureus
A drug-resistant form of S. aureus
S. aureus USA300
A drug-resistant form of a virus
A drug-resustant form of Methicillin aureus
What percentage of people carry any form of Staphylococcus aureus on their skin or in their noses?
1%-5%
5%-10%
10%-25%
30%-40%
50%-60%
What percent of people carry antibiotic-resistant strains of Staphylococcus aureus on their skin or on their noses?
Approximately 2%
Approximately 5%
Approximately 10%
Approximately 12%
Approximately 30%
A student who shares a dorm suite and bathroom with seven other students has contracted a skin infection caused by MRSA. Based on what is known about MRSA and about the student, where would one look first for the source of the bacteria?
contaminated equipment at the gym
contaminated shared food
contaminated used soap and towels
a suitemate with an upper respiratory infection who is sneezing and coughing
shared hypodermic needles
Which person is at the lowest risk of acquiring MRSA?
a computer consultant who works from home
someone who works as a guard at a local prison
a rugby player on a successful team
a worker in a local daycare
a janitor at a major city hospital
Antibiotics should only be prescribed for
fungal infections
viral infections
bacterial and fungal infections
bacterial infections
a flulike illness
ß-lactam antibiotics act by interfering with:
bacterial cell wall synthesis
the uptake of bacteria
bacterial cell division
bacterial chromosome replication
the ability of the bacteria to avoid the host's immune system
MRSA should routinely be treated with:
penicillin
a B-lactam antibiotic
cephalosporin
vancomycin
cephalexin
If the cell wall of Staphylococcus aureus fails to form properly, water will:
create a secondary wall around the cell
drain out of the cell rapidly, causing it to dehydrate
drown the bacteria
rush into the cell, causing it to explode
create a bridge of hydrogen bonds to repair the wall
If the cell wall of Staphylococcus aureus fails to form properly, water will enter the cell:
by the process of osmosis
by the process of imbition
by active transport
to destroy the bacterial DNA
to help maintain the cell's turgor pressure
Why doesn’t a ß-lactam antibiotic prevent the growth of new host (human) cells?
The hosts cells are slowed down by the antibiotic but still grow faster than the bacteria
The host cells are protected by a thick layer of cell-wall peptidoglycan
Osmosis only occurs in bacterial cells, never in human or animal cells
The antibiotic only harms bacterial cell walls; the host cells do not have cell walls
Antibiotics slow host cell growth, but after the bacteria are dead and the antibiotics are removed, the host cells grow again
The MOST accurate statement regarding ß-lactam antibiotics is that:
They are only prescribed for the most drug-resistant forms of Staphylococcus aureus
they cause a cell to burst open by increasing water pressure inside the cell
vancomycin is one of the most effective B-lactams
they must be administered with caution because they can damage human tissues with prolonged use
they are one of the few classes of drugs that are effective against both bacteria and viruses
ß-lactams are effective antibiotics because they
prevent transcription
prevent a cell from acquiring nutrients
prevent a cell from reproducing
inhibit ATP synthesis within cells
cause a cell to burst open
What is the drug of choice when a patient has a severe drug-resistant infection?
penicillin
methicillin
vancomycin
cephalexin
amoxicillin
If a bacterium susceptible to ß-lactam antibiotics were placed in an isotonic solution and exposed to antibiotics
its cell wall would rupture and burst due to the influx of water caused by osmosis.
its cell membrane would rupture and burst due to the influx of water caused by osmosis, but its cell wall would remain intact.
osmosis would drive water out of the cell, causing it to shrivel and die due to lack of internal fluids.
it would remain intact because osmosis would cause no change in water flow into or out of the cell.
it would remain intact because the cell wall is strong enough to withstand the pressure caused when osmosis draws water into the cell.
Bacteria usually reproduce by a process called
Cellular bifurcation
Cleavage
Bipolarization
Binary fission
Divergent fusion
Strains of pneumonia-causing _____ are becoming resistant to every available antibiotic.
Klebsiella
Staphylococcus
Pneumococcus
Botulinum
Streptococcus
Why are antibiotics given to livestock
to reduce bacterial growth in manure
to promote the growth of animals
to improve reproduction
to reduce digestive difficulties
to transmit bacterial resistance
A population of lizards lives on an island and has a large range of adult body sizes. A new predator is introduced to the island, and this predator prefers eating only small lizards. What pattern of natural selection would the lizard population experience as a result of this change in its environment
bifurcating selection
directional selection
diversifying selection
intermediate selection
stabilizing selection
Antibiotic resistance is an example of which pattern of natural selection
bifurcating selection
directional selection
diversifying selection
intermediate selection
stabilizing selection
If two alleles are incompletely dominant to each other and heterozygotes almost never survive, which pattern of natural selection would be observed?
bifurcating selection
directional selection
diversifying selection
intermediate selection
stabilizing selection
Which pattern of natural selection is MOST common in patchy (nonuniform) environments
bifurcating selection
directional selection
diversifying selection
intermediate selection
stabilizing selection
When extreme phenotypes are selected against and disappear, which pattern of natural selection is at work?
bifurcating selection
directional selection
diversifying selection
intermediate selection
stabilizing selection
Which descriptive example will result in diversifying selection?
Giraffes with the longest necks can eat leaves from the tallest trees.
Male frogs that call softly do not attract mates, whereas those who call very loudly get eaten by predators.
In an environment with patches of black and white rocks, both black and white rabbits can hide, but gray rabbits are always visible and are eaten by predators.
Bluebirds with fewer than four chicks do not pass on many genes, bluebirds with four chicks can raise them all, and bluebirds with more than four chicks risk all of them dying due to lack of food.
Black and white moths exist in an area where the trees on which they rest have been turned black by pollution.
A species of small lizard has three color forms: pale gray, brown, and black. In its original range, the colors of the rocky environment were mixed from pale gray to very dark, and the population had an even mix of all three color forms. The blending of colors with the environment helps the lizards hide from predators. A group of these lizards ended up on an island with only gray and black rocks. Eventually, the brown lizards disappeared. This is an example of:
artificial selection
mutation
diversifying selection
directional selection
stabilizing selection
A species of small lizard has three color forms: pale gray, brown, and black. In its original range, the colors of the rocky environment were mixed from pale gray to very dark, and the population had an even mix of all three color forms. The blending of colors with their environment helps the lizards hide from predators. A group of these lizards ended up on an island with all gray rocks. Eventually, only gray lizards remained. This is an example of:
artificial selection
mutation
diversifying selection
directional selection
stabilizing selection
What is decreased as a result of stabilizing selection
the middle phenotypic range of variation
one extreme of the phenotypic variation range
the most suited phenotypic range
population growth
the range of phenotypic variation
Natural selection that favors survival of an intermediate phenotype of a population is called _____ selection
artificial
diversifying
directional
stabilizing
mediophenotypic
Natural selection that favors survival of extreme phenotypes of a population is called _____ selection
artificial
diversifying
directional
stabilizing
mediophenotypic
Finches that live in areas that only have large seeds and small seeds as a food source have adapted their beak sizes in response to this food availability. This is an example of ______ selection
directional
diversifying
guided
stabilizing
uniform
MRSA in humans is an example of ____ selection
directional
diversifying
guided
stabilizing
uniform
Human birth weight is an example of ____ selection
directional
diversifying
guided
stabilizing
uniform
What would the outcome be if an antibiotic-sensitive homogeneous (no variation) strain of S. aureus was grown in the presence of antibiotics?
cell growth that begins slowly but proceeds rapidly
rapid mutation and growth
no cell growth
eventual rise of antibiotic-resistant cells
rapid growth, and then sudden death
Natural selection causes:
Changes in an individual's genes
Changes in allele frequencies within a population
a decrease in reproductive fitness in a population
the inheritance of acquired characteristics
changes in the mechanism of inheritance
Which has made the biggest impact on future generations?
a 5,000-year-old bristlecone pine tree that produced 1 offspring every 100 years
a 5,000-year-old bristlecone pine tree that produced 3 offspring every 100 years
a 3,000-year-old bristlecone pine tree that produced 100 offspring every 100 years
a 2,000-year-old bristlecone pine tree that produced 100 offspring every 10 years
a 500-year-old bristlecone pine tree that produced 100 offspring every year
Which of these is the most fit?
a 5,000-year-old bristlecone pine tree that produced 1 offspring every 100 years
a 5,000-year-old bristlecone pine tree that produced 3 offspring every 100 years
a 3,000-year-old bristlecone pine tree that produced 100 offspring every 100 years
a 2,000-year-old bristlecone pine tree that produced 100 offspring every 10 years
a 500-year-old bristlecone pine tree that produced 100 offspring every year
An organism's ability to survive and reproduce is called the organism's
natural selectivity
advantage
phenotype
genotype
fitness
Five different strains of bacterial cultures were grown overnight in a medium containing antibiotics. Of the resulting population densities listed below, which was the MOST fit?
5 × 105 cells/ml
6 × 106 cells/ml
7.5 × 107 cells/ml
0.075 × 108 cells/ml
5 × 107 cells/ml
Which bacterial phenotype would have the highest fitness if it were cultured in a medium containing antibiotics?
a slightly antibiotic-resistant variant
a moderately antibiotic-resistant variant
a highly antibiotic-resistant variant
an antibiotic-sensitive variant
All phenotypes have equal fitness.
Bacterial fitness is different from the common usage of the word fitness because bacterial fitness refers to:
how quickly bacteria can grow in size.
the amount of ATP a bacterial organism can produce in a given amount of time.
the ability of bacteria to out-compete other microorganisms in a given environment.
how well bacteria can resist drugs and other organisms that intend to kill them.
the ability of bacteria to successfully reproduce in a particular environment.
How would the resistance level of an antibiotic-sensitive variant in culture medium containing a minimal amount of antibiotics change over time?
Resistance will remain low.
Resistance will remain medium.
Resistance will remain high.
Resistance will change from high, to medium, and finally low.
Resistance will change from low, to medium, and finally high.
A highly resistant antibiotic strain of S. aureus would reproduce BEST in:
the presence of antibiotic.
the absence of antibiotic.
the presence or absence of antibiotic.
a moderate concentration of antibiotic.
a fluctuating concentration of antibiotic.
A bacterial strain will MOST likely become antibiotic resistant when it is grown in:
high heat.
extreme cold.
the presence of an acidic environment.
the presence of MRSA.
a laboratory that researches viruses.
A person’s friend has contracted a bacterial infection. Which hypothetical drug would that person suggest as the BEST way to prevent an antibiotic-resistant allele from arising and spreading throughout the bacterial population in the friend’s body?
a drug that prevents mutations but allows gene swapping
a drug that doesn’t prevent mutations but does prevent gene swapping with individuals of its own species
a drug that doesn’t prevent mutations but does prevent gene swapping with individuals of other species
a drug that doesn’t prevent mutations but prevents gene swapping with any individual of any species
a drug that prevents mutations but allows gene swapping
a drug that prevents both mutations and gene swapping
All the individuals of a species living in a specific area compose a
colony
species
community
population
clade
A population is correctly described as
all the members of the same species located on a continent
the species that live in a geographic area
all the species occupying a specific locale
all the members of the same species living in the same area
the species richness
Overprescription of antibiotics and their improper use is a cause of:
a decrease in drug-resistant species.
elimination of drug-resistant species.
a rise in drug-resistant bacterial populations.
keeping the level of MRSA infections stable.
decreasing MRSA levels in hospitals.
What is responsible for genetic variation in bacteria?
mutations in the genome during binary fission
gene influx from a different bacterial strain
DNA influx from the environment
gene transfer from the same bacterial species
all of these
Bacterial cell division is known as:
friction.
cytofission.
fusion.
fission.
nuclear fission.
If bacterial cells can divide every 20 minutes, how many bacteria will be present after 2 hours if the starting population is 100 cells?
700
1200
1300
3200
6400
Which hypothetical antibiotic would treat bacterial infections by interfering with bacterial reproduction?
one that changes one of the proteins on the cell membrane
one that interferes with cell membrane synthesis
one that enhances DNA replication
one that strengthens bacterial cell walls
one that enhances protein synthesis
A bacterial strain divides once every 30 minutes. After 90 minutes, a single bacterium can form a total of _____ bacteria.
3
6
8
16
This answer cannot be calculated from the information given
Bacteria can divide as often as once every
3 hours
minute
hour
day
20 minutes
Binary fission is a form of
nuclear division
aerobic reproduction
anaerobic reproduction
asexual reproduction
sexual reproduction
Each bacterial cell typically splits into ____ new cells
2
3
4
8
20
After bacterial asexual reproduction, the daughter cells produced:
are identical to each other
have half the chromosome number
are genetically different
have double the DNA content
exchange genes by transformation
