Natural Selection
Test Review
Question #1
During his visit to the Galapagos Islands, Charles Darwin discovered 14 distinct
species of finches. These groups had been geographically isolated from one another.
Many of them lived on different islands. The species of finches differed mainly in
feeding behavior, beak structure, and body size. Yet, all of the species shared some
characteristics.
Which of the following statements best explains differences between the finches?
A The beaks of the finches changed so the finches could better
access different sources of food.
B The beaks of the finches changed so all of the finches could eat the
same types of food.
C The beaks of the finches changed as the species of finches
the same island.
migrated to
D The beaks of the finches changed as the finches' body sizes changed.
Answer
Which of the following statements best explains differences
between the finches?
A The beaks of the finches changed so the finches could
better access different sources of food.
Question #2
Darwin used this research to develop the theory of natural selection.
Darwin's theory holds that —
A the perfection of structure produced by natural selection
typically results in a few useful adaptations.
B the similarity of structure produced by natural selection typically
results in a single useful adaptation.
C the lack of gradation of structure produced by natural selection
typically results in no useful adaptations.
D the diversity of structure produced by natural selection typically
results in many useful adaptations.
Answer
Darwin used this research to develop the theory of natural
selection. Darwin's theory holds that —
D the diversity of structure produced by natural selection typically
results in many useful adaptations.
Question #3
A dominant trait is present in 75% of a large population that mates
randomly and lives in a stable environment. After five generations,
without evidence of mutations, the frequency of this dominant trait
would most likely —
A decrease by one-fifth.
B be reduced to zero.
C increase five times.
D remain unchanged.
Answer
A dominant trait is present in 75% of a large population that
mates randomly and lives in a stable environment. After five
generations, without evidence of mutations, the frequency of
this dominant trait would most likely —
D remain unchanged.
Question #4
The frequency of traits which presently offer high adaptive value
to a population may decrease in future generations if —
A the environment changes.
B conditions remain stable.
C mating patterns remain random.
D all organisms with the trait survive.
Answer
• The frequency of traits which presently offer high adaptive
value to a population may decrease in future generations if —
A the environment changes.
Question #5
A trait that does not offer members of a population a great advantage
will most likely —
A appear at the same frequency in successive generations.
B undergo a series of mutations in succeeding generations.
C decrease in frequency in successive generations.
D cause the reproductive rate of individual organisms to
increase.
Answer
• A trait that does not offer members of a population a great
advantage will most likely —
• C decrease in frequency in successive generations.
Question #6
Natural selection acts on a population to produce individual organisms
with different adaptations. Which is true about these adaptations?
A The usefulness of these adaptations is then tested by
interactions in the surrounding environment.
B The usefulness of these adaptations is then reduced by
interactions in the surrounding environment.
C These adaptations are useful to every organism and its
descendants.
D These adaptations are designed so every organism will be
perfectly adapted to its environment.
Answer
• Natural selection acts on a population to produce individual
organisms with different adaptations. Which is true about
these adaptations?
• A The usefulness of these adaptations is then tested by
interactions in the surrounding environment.
Question #7
In an area of Indonesia where the ocean floor is littered with empty coconut
shells, a species of octopus has been filmed "walking" on two of its eight
tentacles. The remaining six tentacles are wrapped around its body. Scientists
suspect that, with its tentacles arranged this way, the octopus resembles a
rolling coconut. Local predators, including sharks, seem not to notice the
octopus as often when it behaves in this manner. This unique method of
locomotion has been utilized by successive generations of octopi through —
A selective breeding of this octopus species.
B competition between octopi and their predators.
C the process of natural selection.
D ecological succession in marine habitats.
Answer
• In an area of Indonesia where the ocean floor is littered with
empty coconut shells, a species of octopus has been filmed
"walking" on two of its eight tentacles. The remaining six
tentacles are wrapped around its body. Scientists suspect that,
with its tentacles arranged this way, the octopus resembles a
rolling coconut. Local predators, including sharks, seem not to
notice the octopus as often when it behaves in this manner.
This unique method of locomotion has been utilized by
successive generations of octopi through —
Question #8
A graph regarding a population of Eastern Chipmunks is shown below.
Natural selection is operating as an evolutionary mechanism on this
chipmunk population. The chipmunks which are most likely to survive
and reproduce can be found in —
A cross section i.
B cross section ii.
C cross section iii.
D cross section iv.
Answer
• A graph regarding a population of Eastern Chipmunks is shown
below.
• Natural selection is operating as an evolutionary mechanism
on this chipmunk population. The chipmunks which are most
likely to survive and reproduce can be found in —
Question #9
Certain insects resemble the bark of the trees on which they live.
Which statement provides the best explanation for this resemblance?
A The trees caused mutations in the insects that resulted in
this protective coloration.
B Natural selection played a role in the development of this
protective coloration.
C The insects needed camouflage so they developed protective
coloration.
D The lack of mutations resulted in the protective coloration.
Answer
• Certain insects resemble the bark of the trees on which they
live. Which statement provides the best explanation for this
resemblance?
Question #10
Natural selection produces change in —
A individuals during their reproductive years, as hormonal
imbalances affect the genotypes of each member of a
population.
B populations over multiple breeding cycles, as mutations
affect the reproductive fitness of different individuals.
C individuals during their lifespan, as developmental changes
affect the phenotypes of each member of a population.
D populations over a single breeding cycle, as advantageous traits
affect the supply of environmental resources of different
individuals.
Answer
• Natural selection produces change in —
B populations over multiple breeding
cycles, as mutations affect the
reproductive fitness of different
individuals.
Question #11
The teeth of carnivores are pointed and are good for puncturing and
ripping flesh. The teeth of herbivores are flat and are good for grinding
and chewing. Which statement best explains these observations?
A The two types of teeth most likely developed as a result of
the needs of an organism.
B Carnivores have developed from herbivores.
C Herbivores have developed from carnivores.
D The two types of teeth most likely developed as a result of
natural selection.
Answer
• The teeth of carnivores are pointed and are good for
puncturing and ripping flesh. The teeth of herbivores are flat
and are good for grinding and chewing. Which statement best
explains these observations?
D The two types of teeth most likely developed as a result of natural
selection.
Question #12
The graph below represents the populations of two different
species in an ecosystem over a period of several years.
Which statement is a possible explanation for the changes
shown?
A Species B is better adapted to this environment.
B Species A is better adapted to this environment.
C Species A is the predator of Species B.
D Species B is a parasite that has benefited Species A.
Answer
The graph below represents the populations of two different
species in an ecosystem over a period of several years.
Which statement is a possible explanation for the changes
shown?
A Species B is better adapted to this environment.
Question #13
Two organisms are categorized in the same species if they —
A have similar structures for aerobic respiration.
B live and feed in the same niche.
C are able to share similar environments and eating
locations.
D are able to mate and produce a fertile offspring.
Answer
• Two organisms are categorized in the same species if they —
D are able to mate and produce a fertile offspring.
Question #14
Genes that are responsible for new traits that help a species
survive in a particular environment will usually —
A not change in frequency.
B decrease gradually in frequency.
C decrease rapidly in frequency.
D increase in frequency.
Answer
• Genes that are responsible for new traits that help a species
survive in a particular environment will usually —
D increase in frequency.
Question #15
According to the theory of natural selection, why are some individuals
more likely than others to survive and reproduce?
A Some individuals are better adapted to their environment
than others.
B Some individuals pass on to their offspring new
characteristics they have acquired during their lifetimes.
C Some individuals do not pass on to their offspring new
characteristics they have acquired during their lifetimes.
D Some individuals tend to produce fewer offspring than
others in the same environment.
Answer
According to the theory of natural selection, why are some
individuals more likely than others to survive and reproduce?
A Some individuals are better adapted to their environment than
others.
Question #16
Genetic drift is a process that causes —
A the genetic makeup of an entire population to be
altered.
B the genetic makeup of an entire population to
disappear.
C organisms to better adapt to their environment.
D organisms to have the same DNA as their parents.
Answer
• Genetic drift is a process that causes —
A the genetic makeup of an entire population to be
altered.
Question #17
After the Industrial Revolution, dark-colored moths outnumbered light-colored
moths in certain regions of England. Within the past 40 years, factories in
these regions have added scrubbers and air purifiers to their smokestacks. The
relative number of light-colored moths has increased. The probable reason for
this increase is that —
A overpopulation occurred and most of the light-colored moths died,
leaving only dark-colored moths to reproduce.
B the environment favored the survival of light-colored moths
over dark-colored moths.
C the allele for light color became dominant over the allele for dark
color.
D the dark color of certain moths faded in direct sunlight.
Answer
• After the Industrial Revolution, dark-colored moths
outnumbered light-colored moths in certain regions of
England. Within the past 40 years, factories in these regions
have added scrubbers and air purifiers to their smokestacks.
The relative number of light-colored moths has increased. The
probable reason for this increase is that —
B the environment favored the survival of light-colored moths over darkcolored moths.
Question #18
Which phrase belongs in box X in the flowchart below?
A Decrease in genetic variability of offspring
B Decreased number of altered genes
C Increase in the production of functional gametes
D Increased chance of cancer
Answer
• Which phrase belongs in box X in the flowchart below?
D Increased chance of cancer
Question #19
The gene frequency for a particular characteristic in a population was
determined to be 80% A (dominant allele) and 20% a (recessive allele).
Fifty years later, the gene frequency was determined to be 60% A and
40% a. What does this change indicate about the gene pool?
A It is undergoing gradual change.
B It has become predominantly recessive.
C It has remained stable.
D It lacks mutations.
Answer
• The gene frequency for a particular characteristic in a
population was determined to be 80% A (dominant allele) and
20% a (recessive allele). Fifty years later, the gene frequency
was determined to be 60% A and 40% a. What does this
change indicate about the gene pool?
A It is undergoing gradual change.
Question #20
The photograph below shows puppies from the same litter.
The physical differences between these puppies likely arise from —
A sorting and recombination of genes.
B mutations and elimination of genes.
C overproduction and selective breeding.
D winter camouflage and asexual reproduction.
Answer
The photograph below shows puppies from the same litter.
The physical differences between these puppies likely arise
from —
A sorting and recombination of genes.
Question #21
One explanation for the variety of organisms present on Earth today is
that over time —
A each niche has changed to support a certain variety of
organism.
B new species have adapted to fill available niches in the
environment.
C gradual genetic change in certain species has produced a
range of species that look similar to one another.
D the environment has remained unchanged, which has led to
successive generations of similar organisms.
Answer
• One explanation for the variety of organisms present on Earth
today is that over time —
B new species have adapted to fill available niches in the
environment.
Question #22
Which situation would most likely result in the highest rate of natural
selection?
A Asexual reproduction of organisms in an unchanging
environment
B Reproduction of organisms in an unchanging environment
with little competition
C Reproduction of a species having a very low mutation rate in
a changing environment
D Reproduction of a species with a high mutation rate in a
changing environment
Answer
• Which situation would most likely result in the highest rate of
natural selection?
D Reproduction of a species with a high mutation rate in a
environment
changing
Question #23
Some behaviors such as mating and caring for young are
genetically determined in certain species of birds. The presence
of these behaviors is most likely due to the fact that —
A individual birds need to learn to survive and reproduce.
B these behaviors helped birds to survive in the past.
C birds do not have the ability to learn.
D birds developed these behaviors within their lifetimes.
Answer
• Some behaviors such as mating and caring for young are
genetically determined in certain species of birds. The
presence of these behaviors is most likely due to the fact that
—
B these behaviors helped birds to survive in the past.
Question #24
A small town on the edge of the Caddo Lake National Wildlife Refuge was heavily infested with
mosquitoes. The town was sprayed with an insecticide for a period of several months. The
graph below shows the results of the daily counts of the mosquito population.
Which of the following statements best explains why some mosquitoes survived after the first
spraying?
A All mosquitoes had a genetic mutation that made them resistant to the
insecticide.
B None of the mosquitoes had a genetic mutation that made them resistant to the
insecticide.
C Only the mosquitoes from the previous generation had a genetic mutation that
made them resistant to the insecticide.
D Some mosquitoes had a genetic mutation that made them resistant to the
insecticide.
Answer
• A small town on the edge of the Caddo Lake National Wildlife
Refuge was heavily infested with mosquitoes. The town was
sprayed with an insecticide for a period of several months. The
graph below shows the results of the daily counts of the
mosquito population.
• Which of the following statements best explains why some
mosquitoes survived after the first spraying?
D Some mosquitoes had a genetic mutation that made them resistant to the insecticide.
Question #25
In order for natural selection to cause a population to develop useful
adaptations, organisms in a population must display different forms of
particular traits. These traits must be associated with —
A rapid, frequent reproduction.
B reproductive fitness.
C a wide range of reproductive organs.
D asexual reproduction.
Answer
• In order for natural selection to cause a population to develop
useful adaptations, organisms in a population must display
different forms of particular traits. These traits must be
associated with —
B reproductive fitness.
Question #26
Look at the diagram of two populations of bacteria below.
The diagram reveals that natural selection operated on the first population of
bacteria. This led to —
A a slight decrease in the amount of diversity in the second
population.
B a slight increase in the amount of diversity in the second
population.
C no diversity in the second population.
D the same amount of diversity in the second population.
Answer
• Look at the diagram of two populations of bacteria below.
• The diagram reveals that natural selection operated on the
first population of bacteria. This led to —
B a slight increase in the amount of diversity in the second
population.
Question #27
When penicillin was first introduced, it was effective in destroying most of the
strains of Neisseria gonorrhoeae, a species of bacterium that causes
gonorrhea. Today, certain strains of Neisseria gonorrhoeae are resistant to
penicillin. Which statement best explains the existence of these resistant
strains?
A Penicillin stimulated certain strains to develop resistance, and the
resistance was passed on to the offspring.
B Penicillin killed the susceptible strains, and strains that were more
resistant survived to reproduce.
C Penicillin used today is not as strong as the penicillin used when it
was first introduced.
D Penicillin over-developed the immune systems of the resistant
strains.
Answer
• When penicillin was first introduced, it was effective in
destroying most of the strains of Neisseria gonorrhoeae, a
species of bacterium that causes gonorrhea. Today, certain
strains of Neisseria gonorrhoeae are resistant to penicillin.
Which statement best explains the existence of these resistant
strains?
B Penicillin killed the susceptible strains, and strains that were more
resistant survived to reproduce.
Question #28
A trait that an organism expresses during its lifetime will only cause its
species to become better adapted if the trait —
A is caused by the genetic code that is present in the gametes
of the organism.
B causes a change in the environment surrounding the
organism.
C decreases the number of genes in the body cells of the
organism.
D results from isolation of the organism from the rest of the
population.
Answer
• A trait that an organism expresses during its lifetime will only
cause its species to become better adapted if the trait —
• A is caused by the genetic code that is present in the gametes
of the organism.
Question #29
Two graphs regarding land snails are shown below.
Which of these conclusions can be made using the two graphs?
A A weight of 5 milligrams (mg) has become a disadvantage for land snails in
this environment.
B Land snails that weigh 25 milligrams (mg) are eating land snails that weight 5
milligrams (mg).
C Heavier land snails migrated out of the area between 2000 and 2010.
D Land snails that weigh more than 20 milligrams (mg) live longer than land
snails that weigh less than 20 milligrams (mg).
Answer
• Two graphs regarding land snails are shown below.
• Which of these conclusions can be made using the two
graphs?
A A weight of 5 milligrams (mg) has become a disadvantage for land snails in
this environment.
Question #30
In an area in Africa, temporary pools form in wetlands. Some fish have
developed the ability to use their ventral fins as "feet" to travel on land
from one temporary pool to another. Fish without this ability die when
the pools dry up. What can be expected to happen in this area after
many years?
A All varieties of fish will survive and produce many offspring.
B The number of fish using ventral fins as "feet" will increase.
C "Feet" in the form of ventral fins will develop on all fish.
D All fish will develop the ability to walk on their ventral fins.
Answer
• In an area in Africa, temporary pools form in wetlands. Some
fish have developed the ability to use their ventral fins as
"feet" to travel on land from one temporary pool to another.
Fish without this ability die when the pools dry up. What can
be expected to happen in this area after many years?
• B The number of fish using ventral fins as "feet" will increase.