Which of the following statements describe
what all members of a population share?
1.
They are temporally isolated from each
other.
They are geographically isolated from
each other.
They are members of the same
species.
They have identical genes.
2.
3.
4.
25%
1
1
2
3
4
5
25%
25%
2
3
25%
4
All the genes of all members of a particular
population make up the population’s
1.
2.
3.
4.
1
relative frequency.
phenotype.
genotype.
gene pool.
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Which statement below about
gene pools is typically true?
1.
They contain two or more alleles for
each inheritable trait.
They contain only dominant alleles.
They belong to two or more
interbreeding species.
The relative frequencies of the
alleles never change.
2.
3.
4.
1
2
3
4
5
25%
1
25%
2
25%
3
25%
4
If an allele makes up one fourth of a
population’s alleles for a given trait, its
relative frequency is
25% 25%
25%
25%
100 percent.
75 percent.
25 percent.
4 percent.
1.
2.
3.
4.
1
2
3
4
5
1
2
3
4
Interbreeding among members
of a population results in
1.
different types of alleles in the gene
pool.
changes in the relative frequencies of
alleles in the gene pool.
no changes in the relative frequencies
of alleles in the gene pool.
an absence of genetic variation in the
population.
2.
3.
4.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
In a population, the sum of the relative
frequencies of all alleles for a particular trait
is
1. equal to 100
percent.
2. equal to the number
of alleles for the trait.
3. constantly changing.
4. dependent on the
number of alleles.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
A change in a sequence of DNA
is called a
1.
2.
3.
4.
1
recombination.
polygenic trait.
single-gene trait.
mutation.
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The two main sources of
genetic variation are
1. genotypes and phenotypes.
2. gene shuffling and mutations.
3. single-gene traits and
polygenic traits.
4. directional selection and
disruptive selection.
1
2
3
4
5
25%
1
25%
2
25%
3
25%
4
In many kinds of organisms, inheritable
differences are due mostly to
1. mutations during
gamete formation.
2. polygenic traits.
3. gene shuffling during
gamete formation.
4. the effects of
radiation.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Gene shuffling includes the independent
movement of chromosomes during meoisis
as well as
1. mutations from
radiation.
2. changes in the
frequencies of
alleles.
3. crossing-over.
4. mutations from
chemicals.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
In a particular population, sexual
reproduction can produce
1. mutations.
2. many different
phenotypes.
3. new allele
frequencies.
4. meiosis.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The gene shuffling that occurs
as part of sexual reproduction
1. changes the gene pool’s allele
frequencies.
2. does not change the gene
pool’s allele frequencies.
3. keeps the phenotypes
consistent.
4. is caused by radiation or
chemicals.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
A single-gene trait that has two alleles and
that shows a simple dominant-recessive
pattern will result in
25% 25%
25%
25%
1. one phenotype.
2. two phenotypes.
3. four phenotypes.
4. millions of
phenotypes.
1
2
3
4
5
1
2
3
4
An example of a single-gene
trait is
1. widow’s peak in
humans.
2. weight of human
infants at birth.
3. height in humans.
4. beak size in the
Galápagos finches.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The number of phenotypes produced
for a given trait depends upon
1.
the number of genes
that control the trait.
which form of the trait is
dominant.
the relative frequencies
of the various alleles.
the relationship of allele
frequencies to
Mendelian ratios.
2.
3.
4.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The phenotypes for a typical polygenic
trait can often be expressed as
1. a bar graph.
2. a bell-shaped
curve.
3. Mendelian ratios.
4. allele frequencies.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Compared to a polygenic trait, a
single-gene trait tends to have
1. fewer phenotypes.
2. more phenotypes.
3. the same number
of phenotypes.
4. phenotypes that
form a bellshaped curve.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
A polygenic trait can have
1.
many possible genotypes, but few
possible phenotypes.
many possible genotypes, producing
many possible phenotypes.
fewer phenotypes than most singlegene traits.
fewer genotypes than most singlegene traits.
2.
3.
4.
1
2
3
4
5
25%
1
25%
2
25%
3
25%
4
Natural selection acts directly
on
1.
2.
3.
4.
1
alleles.
genes.
phenotypes.
mutations.
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Which of the following is NOT a way in
which natural selection affects the
distribution of phenotypes?
25% 25%
25%
25%
directional
selection
stabilizing
selection
disruptive
selection
chance events
1.
2.
3.
4.
1
2
3
4
5
1
2
3
4
When individuals at only one end of a bell
curve of phenotype frequencies have high
fitness, the result is
25% 25%
25%
25%
1. directional
selection.
2. stabilizing
selection.
3. disruptive
selection.
4. genetic drift.
1
2
3
4
5
1
2
3
4
When individuals with an average form of a
trait have the highest fitness, the result is
1. not predictable.
2. disruptive
selection.
3. directional
selection.
4. stabilizing
selection.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
In a population of finches in which one group of
birds has a short, parrotlike beak and another
group has a long, narrow beak, what process has
probably occurred?
1. directional
selection
2. disruptive
selection
3. stabilizing
selection
4. genetic drift
1
2
3
4
5
25%
1
25%
2
25%
3
25%
4
If a mutation introduces a new skin color in a lizard
population, which factor might determine whether
the frequency of the new allele will increase?
1.
2.
how many other alleles are present
whether the mutation makes some lizards
more fit for their environment than other
lizards
how many phenotypes the population has
whether the mutation was caused by
nature or by human intervention
3.
4.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
In genetic drift, allele
frequencies change because of
1.
2.
3.
4.
1
mutations.
chance.
natural selection.
genetic
equilibrium.
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Which of the following events do
biologists consider a random change?
1. directional
selection
2. speciation
3. disruptive
selection
4. genetic drift
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Genetic drift tends to occur in
populations that
1. are very large.
2. are small.
3. are formed from
new species.
4. have unchanging
allele frequencies.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The type of genetic drift that follows the
colonization of a new habitat by a small
group of individuals is called
1. the Hardy-Weinberg
principle.
2. the founder effect.
3. directional selection.
4. stabilizing selection.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
One similarity between natural selection and
genetic drift is that both events
1.
are based completely
on chance.
begin with one or more
mutations.
involve a change in a
population’s allele
frequencies.
take place only in very
small groups.
2.
3.
4.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The situation in which allele frequencies of a
population remain constant is called
1. evolution.
2. genetic drift.
3. genetic
equilibrium.
4. natural selection.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
One of the conditions required to
maintain genetic equilibrium is
1. natural selection.
2. mutations.
3. nonrandom
mating.
4. no movement into
or out of the
population.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The genetic equilibrium of a population can
be disturbed by each of the following
EXCEPT
1. nonrandom mating.
2. movement into and
out of the
population.
3. a large population
size.
4. mutations.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The allele frequencies of a population
are more likely to remain unchanged if
1. the population size
is reduced.
2. frequent movement
into and out of the
population occurs.
3. all mating is random.
4. the mutation rate
increases.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
According to the Hardy-Weinberg principle,
genetic equilibrium would be more likely in a
population of mice if
1.
the population size
rapidly decreases.
mutation rates within the
population rise.
no natural selection
takes place.
there is frequent
movement into and out
of the population.
2.
3.
4.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Which factor would most likely disrupt
genetic equilibrium in a large population?
1.
the production of large
numbers of offspring
mating that is not
random
the absence of
movement into and out
of the population
the absence of
mutations
2.
3.
4.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The separation of populations by barriers
such as rivers, mountains, or bodies of
water is called
1. temporal isolation. 25% 25% 25% 25%
2. geographic
isolation.
3. behavioral
isolation.
4. genetic
equilibrium.
1
2
3
4
5
1
2
3
4
A factor that is necessary for the
formation of a new species is
1. reproduction at
different times.
2. geographic barriers.
3. different mating
behaviors.
4. reproductive
isolation.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
What situation might develop in a population having some
plants whose flowers open at midday and other plants
whose flowers open late in the day?
1. behavioral
isolation
2. geographic
isolation
3. temporal isolation
4. genetic drift
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The geographic isolation of two populations
of a species tends to increase differences
between their gene pools because it
1.
prevents interbreeding between the
populations.
prevents interbreeding within each
population.
causes temporal isolation of the two
populations.
increases differences in courtship
behavior.
2.
3.
4.
1
2
3
4
5
25%
1
25%
2
25%
3
25%
4
Although they often live in the same habitat, the American
toad breeds earlier in the spring than the Fowler’s toad
does. What can be inferred from this information?
1.
The two species do not interbreed
because of geographic isolation.
The two species do not interbreed
because of temporal isolation.
The two species interbreed throughout
the spring season.
The American toad will cause the
extinction of the Fowler’s toad.
2.
3.
4.
1
2
3
4
5
25%
1
25%
2
25%
3
25%
4
Which is the first step that occurred in the
speciation of the Galápagos finches?
1. establishing genetic
equilibrium
2. behavioral isolation
3. ecological
competition
4. arrival of the
founding population
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
The Galápagos finch species
are an excellent example of
1. speciation.
2. genetic
equilibrium.
3. stabilizing
selection.
4. selection on
single-gene traits.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
What did Peter and Rosemary Grant learn
about mate choice from the Galápagos
finches?
1.
2.
Phenotype plays no role in mate choice.
Finches prefer mates with beaks similar in
size to their own.
Finches prefer mates with smaller beaks
than their own.
Finches prefer mates with larger beaks
than their own.
3.
4.
25%
1
1
2
3
4
5
25%
25%
2
3
25%
4
In Rosemary and Peter Grant’s study of the
Galápagos finches, what process was encouraged
by ecological competition during the dry season?
1. stabilizing
selection
2. disruptive
selection
3. directional
selection
4. genetic drift
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Which statement about evolution in
the Galápagos finches is true?
1.
Natural selection on beak size and
shape is driven by available food.
Stabilizing selection has favored an
intermediate beak type for all of the
finches.
Mate choice likely plays no role in the
finches’ evolution.
None of the finch species is
reproductively isolated.
2.
3.
4.
1
2
3
4
5
25%
1
25%
25%
2
3
25%
4
Because all members of a population can
interbreed, biologists often study their genes as a
single group. _________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
In a gene pool, as the relative frequency of one allele for a
trait increases, the relative frequencies of other alleles for
that trait decrease. _________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
Most inheritable differences are due to
mutations that occur during the production of
gametes. _________________________
1. True
50%
50%
2. False
1
2
3
4
5
1
2
Mutations do not always affect an organism’s genotype—its
physical, behavioral, and biochemical characteristics.
_________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
A polygenic trait is controlled by one
gene. _________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
On a graph, the distribution of phenotypes for a
single-gene trait tends to form a bell-shaped curve.
_________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
Natural selection on single-gene traits can
lead to changes in allele frequencies.
_________________________
1. True
50%
50%
2. False
1
2
3
4
5
1
2
In a population of snakes with a range of body lengths, if
the longest individuals have the highest fitness, disruptive
selection is likely to occur. _________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
In small populations, an allele can become
more or less common simply by chance.
_________________________
1. True
50%
50%
2. False
1
2
3
4
5
1
2
Genetic drift may occur when a small group
of individuals colonize a new habitat.
_________________________
1. True
50%
50%
2. False
1
2
3
4
5
1
2
When mutations introduce new alleles into a
population, genetic variation is disrupted.
_________________________
1. True
50%
50%
2. False
1
2
3
4
5
1
2
In a population of birds, if females prefer males with long
tails, the population violates the condition of directional
selection described by the Hardy-Weinberg principle.
_________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
In the type of reproductive isolation called behavioral
isolation, two populations are separated by barriers such as
rivers or mountains. _________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
Two populations that have overlapping ranges can remain
reproductively isolated through behavioral isolation or
temporal isolation from each other.
_________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
The first step of the speciation of the Galápagos
finches likely was the arrival of founders from
South America. _________________________
1. True
2. False
1
2
3
4
50%
5
1
50%
2
Participant Scores
0
0
Participant 1
Participant 2
0
0
0
Participant 3
Participant 4
Participant 5
A ____________________ is all genes
present in a particular population.
1
2
3
4
5
0 of 5
Crossing-over can occur during the meiotic
divisions that produce cells called
____________________.
1
2
3
4
5
0 of 5
Most inherited differences in the appearances of two
brothers are due to the _________________________ that
occurred during the production of gametes in their parents.
1
2
3
4
5
0 of 5
The number of possible phenotypes for a
given trait depends on how many
____________________ control the trait.
1
2
3
4
5
0 of 5
A polygenic trait can have many possible
genotypes and ____________________.
1
2
3
4
5
0 of 5
For ____________________ traits, natural
selection can affect the distribution of
phenotypes in three different ways.
1
2
3
4
5
0 of 5
The pattern of natural selection that acts most strongly
against gray individuals in a population that ranges from
black through gray to white is ____________________
selection.
1
2
3
4
5
0 of 5
When the phenotypes of polygenic traits are represented
by a bell curve, the ____________________ of individuals
close together on the curve is not very different.
1
2
3
4
5
0 of 5
In genetic drift, ____________________, not natural
selection, plays a primary role in determining the number of
descendants an organism has.
1
2
3
4
5
0 of 5
According to the _________________________ principle,
allele frequencies in a population will remain constant
unless one or more of five specific factors cause those
frequencies to change.
1
2
3
4
5
0 of 5
When a population is NOT evolving, it is in a
situation called
_________________________.
1
2
3
4
5
0 of 5
For new species to evolve, populations must
be ____________________ isolated from
each other.
1
2
3
4
5
0 of 5
If two populations have been reproductively isolated and
can no longer breed and produce fertile offspring, the
process of _________________________ has occurred.
1
2
3
4
5
0 of 5
In the Galápagos finches that Rosemary and Peter Grant
studied, a pattern of natural selection called
____________________ selection favored individuals with
larger, heavier beaks during a drought.
1
2
3
4
5
0 of 5
In a particular environment, populations that are very
different from each other are less likely to
____________________ with each other for resources.
1
2
3
4
5
0 of 5
Are the members of a population
necessarily the same species? Explain
1
2
3
4
5
0 of 5
Explain how you could calculate the relative
frequency of an allele in a gene pool.
1
2
3
4
5
0 of 5
What are the two main sources of genetic
variation? Which of them is more common?
1
2
3
4
5
0 of 5
Would a trait that has only two distinct
phenotypes more likely be a single-gene
trait or a polygenic trait? How do you know?
1
2
3
4
5
0 of 5
What does a bell-shaped curve showing the
phenotypes for human height indicate about the
relative number of very short and very tall people?
1
2
3
4
5
0 of 5
Explain how stabilizing selection would
affect a graph of the distribution of
phenotypes for a trait.
1
2
3
4
5
0 of 5
Is an allele for a trait that has no effect on a
species’ fitness affected by natural
selection? Explain
1
2
3
4
5
0 of 5
Why might genetic drift occur if a small
number of individuals colonize a new
habitat?
1
2
3
4
5
0 of 5
How does the size of a population affect the
likelihood that its genetic crosses will produce the
ratio of alleles predicted by the laws of probability?
1
2
3
4
5
0 of 5
List the five conditions necessary to
maintain genetic equilibrium in a population.
1
2
3
4
5
0 of 5
Which population, one of nearly identical organisms or one
of phenotypically varied organisms, would be more likely to
remain in genetic equilibrium?
1
2
3
4
5
0 of 5
Why might a geographic barrier such as a large
river cause the formation of a new species of small
rodents but not a new species of birds?
1
2
3
4
5
0 of 5
What are three mechanisms for reproductive isolation?
Which mechanism isolates two populations of similar frogs
with different mating calls?
1
2
3
4
5
0 of 5
How does the work of Peter and Rosemary
Grant in the Galápagos relate to the work of
Charles Darwin?
1
2
3
4
5
0 of 5
What are the major steps that were likely
involved in the speciation of the Galápagos
finches?
1
2
3
4
5
0 of 5
For a trait that has many different alleles, would an
individual in the population be more likely to have that allele
if it has a low relative frequency or a high relative
frequency? Why?
1
2
3
4
5
0 of 5
If the relative frequency of a single allele for a particular
trait declines over time, what would happen to the relative
frequencies of some or all other alleles for that trait?
Explain
1
2
3
4
5
0 of 5
Explain how shuffling a deck of playing cards can be a
good model for the effect of sexual reproduction on the
relative frequency of alleles in a population and the
possible combinations of alleles.
1
2
3
4
5
0 of 5
Define mutation and describe one situation in which a point
mutation—the alteration of a single nucleotide—would
affect an organism’s phenotype and another situation in
which a point mutation would not affect phenotype.
1
2
3
4
5
0 of 5
For a population, are the frequencies of phenotypes for a
single-gene trait best expressed by a bar graph or a curve?
Are the frequencies of phenotypes for a polygenic trait best
expressed by a bar graph or a curve? Explain
1
2
3
4
5
0 of 5
How are directional selection and disruptive
selection similar? How are they different?
1
2
3
4
5
0 of 5
Describe the founder effect, and describe
the conditions in which it arises.
1
2
3
4
5
0 of 5
The Hardy-Weinberg principle describes the conditions
needed for the frequency of alleles in a population to
remain unchanged. Explain why that stability occurs.
1
2
3
4
5
0 of 5
Assume that a geographic barrier that results in two very different
ecosystems splits a single population. What would likely happen to the
two separate populations? Would this process occur more quickly, less
quickly, or at the same rate as it would if the two populations lived in
similar ecosystems?
1
2
3
4
5
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If each of the Galápagos Islands had contained an identical
assortment and abundance of vegetation, would the impact
of natural selection have been as pronounced as it was?
Explain
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