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Unit 4: Life’s Organizing Principle: Evolution and the Diversity of Life
Chapter 17. The Means of Evolution: Microevolution
Chapter 17 Post-Test
Chapter 17 Post-Test
This activity contains 39 questions.
What is an allele?
a particular version of a gene
the gene pool of a population
a particular trait
What is the definition of
a select number of a given species in a defined region
all of the members of a species that live in a defined geographic region at a given time
all of the members of an ecosystem
all of the members of a species
Which of the following groups of organisms is subject to evolution?
the total number of gorillas found in zoos all over the world
the dolphins found in aquatic parks throughout the world
the Thoroughbred racehorses found throughout the United States
the grass frogs found in Minnesota
For scientists to analyze evolutionary change in populations, they must think of individual genes as ________.
members of a gene pool that is subject to random change because of mutations and rearrangements
theoretical entities used to represent unknown quantities within organisms
entities whose passage through generations is preordained by selective forces
stable entities, not susceptible to change
Evolution that results in the formation of new species or other large groupings of living things is defined as _____________.
Which of the following could be considered a definition of
a change in the genetic makeup of an individual
a change in environmental conditions
a change in the gene pool of a population
a change in the physical characteristics of an individual
A scientist notices that over a period of 10 years, spotted frogs, which were rare in a population of solid green frogs, have become almost 30 percent of the population. What phenomenon has occurred in these frogs?
If a population is to undergo NO evolution, what must occur?
Mutations must be frequent.
Mating must not be random.
Its allele frequencies must be constant.
The population must be very small.
Unlike the other mechanisms that can cause microevolution, natural selection always works in concert with ______ to make organisms more fit.
a small population of organisms
totally random mating
On a remote Pacific island, a species of rabbits can be found that have very short, reduced ears. During a storm, a package containing live, domesticated rabbits is washed over the side of a ship and eventually washed onto the shore of the island. Within only a few generations, the population of island rabbits has changed so that 50 percent of them have short ears and 50 percent have long ears. This is an example of microevolution through ______.
Along the length of a river resides a species of green sunfish. To provide electricity to area homes, a hydroelectric dam is built that separates the lower river area from a newly formed lake above. After many years, the green sunfish in the river and lake are sampled and found to be phenotypically very different. Which of the following scenarios is the best hypothesis to explain the microevolutionary changes observed?
The dam caused various environmental conditions to be formed in the lake versus the river, and natural selection selected for the best-fit organisms in both environments.
The dam forced an increase in the amount of gene flow between the populations, and natural selection selected for the best-fit organisms in each group.
The presence of the dam increased the amount of random mating that occurred between the river and lake fish, and natural selection selected for the best-fit organisms.
The electricity produced in the dam caused mutations in the river sunfish, and natural selection selected for the best-fit organisms.
For what reason is it rather unwise for organisms to inbreed?
Inbreeding reduces the fitness of the parents.
Inbreeding brings together recessive alleles, resulting in higher probabilities of genetic diseases.
Inbreeding can slow the process of speciation.
Inbreeding results in very high mutation rates.
A scientist conducting a long-term study of bluebirds in a Minnesota forest notices that the males have become a more brilliant blue over the last 30 years. Of what advantage could this be to the population?
Brighter bluebirds are easier for hawks to see and capture.
This is just a matter of chance and has no effect on the population.
This increases the chance of random matings.
Brighter males probably attract females preferentially.
Most mutations that occur in an organism ________.
kill the organism
make the organism better adapted to its environment
make the organism less adapted to its environment
have little or no effect on the life of the organism
Water currents, wind currents, and animal dispersal of seeds are examples of which kind of evolutionary activity?
The hunting of seals in the 1890s produced which effect on their populations?
The massive development we see of a peacock's tail is a good example of ________.
If you were to take a population of 20 flies that have an allele frequency for
of 5 percent and killed 10 of them, what would happen to the allele frequency of
It would change, but it is not clear whether it would be greater or eliminated.
It would not change.
There is not enough information to determine whether the allele frequency of
It would be reduced to 0 percent.
If a small group of humans were to colonize a new planet and remain isolated, what would likely be the impact on this group's allele frequency?
It would balance out to the original allele frequency of the human population because of gene flow.
It will be the same as that of the whole human population.
It would be different from that of the whole human population because of the founder effect.
Natural selection would likely reproduce identical allele frequencies in both the small group and the whole human population.
Which of the following evolutionary forces consistently works to adapt organisms to their environment?
If an albino variant suddenly appears in a population of frogs ranging from solid green to spotted green, the new phenotype is probably the result of _________.
Which of the following is one of the reasons that natural selection works on populations rather than on individuals?
Evolution takes place across generations, not in an organism's own lifespan.
Individuals cannot develop new alleles, but populations can.
Populations are too large for natural selection to have an effect.
Populations have different genes from individuals.
From an evolutionary viewpoint, the most important characteristic of a mutation is that it _______.
shows outwardly in the carrier of the new mutation
occurs in the reproductive cells that produce either sperm or eggs
produces a beneficial effect
produces a deleterious effect
The mutation rate in humans is______.
one DNA base pair per 1,000
one DNA base pair per 100,000
one DNA base pair per 1 million
one DNA base pair per 1 billion
The movement of alleles from one population to another is accomplished through _________.
the bottleneck effect
Why are the results of genetic drift so difficult to predict?
Small populations tend not to have mutations.
Small populations are subject to greater statistical chance.
It is difficult to move genes from one generation to the next.
Small populations evolve at a slower rate.
People often see evolution as a struggle for existence and "survival of the fittest." In reality, evolution is based on __________.
reproduction of the fittest
survival of the strongest
survival of the largest
survival of the smartest
What did the 1970s, study on the finch
Natural selection is impossible to observe on a short time scale, such as a human life.
Natural selection can happen in short order under certain conditions.
Natural selection tends to produce larger, more aggressive animals.
Finches are somehow immune to the process of natural selection.
Which of the following is the relative ability of an organism to pass its genes on?
What did the study of finches in the Galapagos show?
The most aggressive birds were most fit.
The bird with the largest bill was the most fit.
One particular bird was most fit.
Different traits were favored under different environmental conditions.
How does natural selection increase the fitness of an organism?
Natural selection makes individuals stronger.
Natural selection makes individuals larger.
Natural selection makes individuals smarter.
Natural selection increases an individual's reproductive efficiency.
What did Peter and Rosemary Grant discover in their studies of Galapagos finches?
Finches with larger beaks were able to feed on the more abundant large seeds.
Finches responded to drought by growing larger beaks.
Finches responded to drought by growing smaller beaks.
Natural selection had no effect on the finches.
Which of the following statements is true?
In stabilizing selection, the mean character remains unchanged, and the variation about the mean decreases.
In stabilizing selection, the mean character remains unchanged, and the variation about the mean remains unchanged.
In stabilizing selection, the mean character decreases, and the variation about the mean decreases.
In stabilizing selection, the mean character changes, and the variation about the mean decreases.
When the environmental conditions select against organisms at only one extreme of the range of diversity in a population, the results will be ______.
Why are polygenic characters particularly susceptible to the forces of natural selection?
They seldom are expressed as extreme phenotypes.
They are especially resistant to the forces of natural selection.
They are continuously variable.
They are very rare in populations.
If a population of lizards that normally eat small insects expands its range into an area that has both small and large insects available, what type of natural selection would you expect to see in this population?
Natural selection is not possible in this situation.
Why do most human infants weigh less than 7 pounds at birth?
Human females have become smaller in recent years.
This birth weight is the most adaptive.
Pregnancy does not last as long now as it did in the past.
More women are giving birth by cesarean section.
If a recessive allele is found in 11 percent of a population and NO selective forces are acting on the allele, what will be its frequency in the next generation?
If there are two alleles for a gene,
, and the frequency of the
allele is 0.72, what is the frequency of organisms that are of the
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