A storm separates a small number of birds in a migrating population. These birds end up at a destination different from where they usually migrate and establish a new population in this new area.
This is an example of __________.
ANSWER
the founder effect
the bottleneck effect
gene flow
natural selection
mutation
answer
the founder effect
question
The sickle-cell allele, which is recessive, causes anemia but confers resistance to malaria in individuals who possess it. However, homozygous recessive individuals often die from anemia but not from malaria, and homozygous dominant individuals do not have anemia but could die from malaria. Heterozygous individuals have the highest relative fitness.
This is an example of __________.
ANSWER
the heterozygote advantage
the homozygous dominant advantage
the homozygous recessive advantage
genetic drift
gene flow
answer
the heterozygote advantage
question
Which of the following statements correctly describes a population in Hardy-Weinberg equilibrium?
ANSWER
Allele and genotype frequencies in the population will remain constant from generation to generation.
Allele and genotype frequencies in the population change from generation to generation.
The population is evolving.
The population exhibits no genetic variation.
All of the listed responses are correct.
answer
Allele and genotype frequencies in the population will remain constant from generation to generation.
question
In a population that is in Hardy-Weinberg equilibrium, 64% of the individuals express the recessive phenotype for a particular gene locus. What is the expected frequency of the recessive allele in this population?
ANSWER
0.8
0.64
1
0.36
0.2
answer
0.8
question
A hurricane hits a small island, killing all but a few members of a bird population. This is an example of __________.
ANSWER
the bottleneck effect
the founder effect
gene flow
natural selection
random mating
answer
the bottleneck effect
question
All of the following conditions are required for Hardy-Weinberg equilibrium except __________.
ANSWER
natural selection
a large population
no mutation
no gene flow
random mating
answer
natural selection
question
Point mutations in noncoding regions of DNA result in __________.
ANSWER
neutral variation
phenotypic variation
gene variability
population variation
molecular variability
None of the listed responses is correct.
answer
neutral variation
question
Which of the following statements explains why male peacocks with brightly colored feathers are more prevalent than those with plain colors?
ANSWER
Female peacocks choose the showiest males as mates, causing this trait to be more prevalent in the population.
Female peacocks choose the plain-colored males as mates, causing this trait to be more prevalent in the population.
Showy males are larger and kill off the plain-colored males.
Female mate choice is random, and the showier males happen to be chosen by the females as mates.
Male peacocks with showy feathers have no selective advantage over plain-colored males.
answer
Female peacocks choose the showiest males as mates, causing this trait to be more prevalent in the population.
question
Stabilizing selection __________.
ANSWER
favors intermediate variants in a population
prevents mutations from occurring
occurs when some individuals migrate to an area with different environmental conditions
usually results in two distinct phenotypes
occurs only in plants
answer
favors intermediate variants in a population
question
Which type of selection maintains stable frequencies of two or more phenotypic forms in a population?
ANSWER
Balancing selection
Neutral variation
Heterozygote advantage
Stabilizing selection
Directional selection
answer
Balancing selection
question
A population of squirrels is preyed on by small hawks. The smaller squirrels can escape into burrows. The larger squirrels can fight off the hawks. After several generations, the squirrels in the area tend to be very small or very large.
What process is responsible for this outcome?
ANSWER
Disruptive selection
Stabilizing selection
Directional selection
Balancing selection
Hardy-Weinberg equilibrium
answer
Disruptive selection
question
In the context of populations, how do we define evolution?
ANSWER
Evolution is a change in a population's allele frequencies over generations.
Evolution is the tendency for some individuals in a population to leave more offspring than others.
Evolution is the way in which sexual reproduction can rapidly spread advantageous traits throughout a population.
Evolution is the explanation for how organic molecules formed from inorganic molecules.
Evolution is always caused by natural selection.
answer
Evolution is a change in a population's allele frequencies over generations.
question
Which of the following sets of conditions is required for Hardy-Weinberg equilibrium?
ANSWER
Random mating, no natural selection, and a large population
A large population, no mutations, with natural selection
A large population, random mutations, and no migration of alleles in or out of the population
No mutations, no natural selection, with sexual selection
Random mating, a small population, and no mutations
answer
Random mating, no natural selection, and a large population
question
No two people are genetically identical, except for identical twins. The main source of genetic variation among human individuals is __________.
ANSWER
the reshuffling of alleles in sexual reproduction
new mutations that occurred in the preceding generation
genetic drift due to the small size of the population
geographic variation within the population
environmental effects
answer
the reshuffling of alleles in sexual reproduction
question
Which of the following is the best example of gene flow?
ANSWER
Wind blows pollen from one population of plants to another and cross-fertilization occurs.
A small population of humans colonizes a newly formed island.
Genes are shuffled by the crossing over of chromosomes during meiosis.
An earthquake results in the formation of a canyon, splitting a population of toads apart.
A fire drastically reduces the size of a white-tailed deer population. The remaining individuals spread out throughout the remaining forest.
answer
Wind blows pollen from one population of plants to another and cross-fertilization occurs.
question
The gene pool of a population consists of __________.
ANSWER
all copies of every type of allele at every locus in all members of the population
only the gene loci that are heterozygous
only the gene loci that are homozygous
only the gene loci that exhibit variation within the population
all of the genes in a single organism
all of the genes in the females of a population
answer
all copies of every type of allele at every locus in all members of the population
question
In the Hardy-Weinberg equation, 2pq represents __________.
ANSWER
the expected frequency of the heterozygous genotype
the expected frequency of the homozygous recessive genotype
the expected frequency of the homozygous dominant genotype
the expected frequency of the dominant allele
the expected frequency of the recessive allele
answer
the expected frequency of the heterozygous genotype
question
In a certain group of African people, 4% are born with sickle-cell disease (homozygous recessive). If this group is in Hardy-Weinberg equilibrium, what percentage of the group has the selective advantage of being more resistant to malaria (heterozygous) than those individuals who are homozygous for normal hemoglobin or for sickle-cell disease?
ANSWER
32%
2%
4%
8%
16%
answer
32
question
Which type of mutation plays the most important role in increasing the number of genes in the gene pool?
ANSWER
Duplication
Mutations are so rare that there are no mutations that can have such an important effect.
Point mutation
Rearrangement of gene loci
Changes in nucleotide sequence
answer
Duplication
question
Which of the following statements correctly describe(s) characteristics of genetic drift?
ANSWER
All of the listed responses are correct.
It is significant in small populations.
It can cause allele frequencies to change at random.
It can lead to a loss of genetic variation in a population.
It can cause harmful alleles to become fixed in a population.
answer
All of the listed responses are correct.
question
At what level does gene variability quantify genetic variation?
ANSWER
Whole-gene
Molecular
Population
Species
Individual
answer
Whole-gene
question
Which statement below is true about sexual selection?
ANSWER
Sexual selection can result in sexual dimorphism—marked differences between the sexes in secondary sexual characteristics that are not associated directly with reproduction.
Intrasexual selection leads to the death of most unfit males in combat.
Showy secondary sexual characteristics cannot be explained because they break all of the rules of natural selection.
In most vertebrates, females court the males.
There is no evidence that intrasexual selection takes place between females.
answer
Sexual selection can result in sexual dimorphism—marked differences between the sexes in secondary sexual characteristics that are not associated directly with reproduction.
question
In a population that is in Hardy-Weinberg equilibrium, 64% of the individuals express the recessive phenotype for a particular gene locus. What is the expected frequency of the dominant allele in this population?
ANSWER
0.2
0.8
0.64
0.04
1
answer
0.2
question
Which of the following can form entirely new alleles?
ANSWER
Mutation
Natural selection
Genetic drift
Sexual recombination
The environment
answer
mutation
question
Which of the following would seem to be an example of neutral variation?
ANSWER
Human fingerprints
Homozygosity of the cheetah population
Polymorphism of the Galápagos finches
Founder effect
Moth coloration
answer
Human fingerprints
question
Sexual recombination includes the shuffling of chromosomes in __________ and fertilization.
ANSWER
meiosis
mitosis
genetic drift
natural selection
mutation
answer
meiosis
question
Natural selection leads to adaptation, but there are many organisms on Earth that exhibit characteristics that are less than ideal for their environment. Which of the following statements correctly explain(s) this?
ANSWER
All of the listed responses are correct.
Selection can act only on existing variations.
Evolution is limited by historical constraints.
Adaptations are often compromises.
Chance, natural selection, and the environment interact.
answer
All of the listed responses are correct
question
In a large population of randomly breeding organisms, the frequency of a recessive allele is initially 0.3. There is no migration and no selection. Humans enter this ecosystem and selectively hunt individuals showing the dominant trait. When the gene frequency is reexamined at the end of the year, __________.
ANSWER
the frequency of the homozygous dominants will go down, the frequency of the heterozygous genotype will go down, and the frequency of the homozygous recessives will go up
the frequency of the homozygous dominants will go down, the frequency of the heterozygous genotype will go up, and the frequency of the homozygous recessives will remain the same
the frequency of the homozygous dominants will go down, the frequency of the heterozygous genotype will remain the same, and the frequency of the homozygous recessives will go up
the frequency of the homozygous dominants will go up, the frequency of the heterozygous genotype will go down, and the frequency of the homozygous recessives will go down
the frequency of the homozygous dominants will go up, the frequency of the heterozygous genotype will go down, and the frequency of the homozygous recessives will go up
answer
the frequency of the homozygous dominants will go down, the frequency of the heterozygous genotype will go down, and the frequency of the homozygous recessives will go up
question
Antibiotic resistance in bacteria is an example of which of the following?
ANSWER
Directional selection
Stabilizing selection
Disruptive selection
Hardy-Weinberg equilibrium
Macroevolution
answer
Directional selection
Haven't found what you need?
Search for quizzes and test answers now
Quizzes.studymoose.com uses cookies. By continuing you agree to our cookie policy