BIO 121 Exam 3
Whole-gene
The molecular level describes genetic variation as nucleotide variability.
Although populations do vary in their characteristics, it is at the gene level that
genetic variation can be quantified.
Although species do vary in their characteristics, it is at the gene level that
genetic variation can be quantified.
Individuals may vary in a population, but it is at the gene level that genetic
variation can be quantified. - Correct Answer - At what level does gene variability
quantify genetic variation?
Disruptive Selection
Disruptive selection favors individuals at both ends of the phenotypic spectrum. -
Correct Answer - 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?
natural selection - Correct Answer - All of the following conditions are required
for Hardy-Weinberg equilibrium except __________.
A large population is required for Hardy-Weinberg equilibrium.
A population without mutations is required for Hardy-Weinberg equilibrium.
,A population without gene flow is required for Hardy-Weinberg equilibrium.
Random mating in a population is required for Hardy-Weinberg equilibrium. -
Correct Answer - Conditions for the Hardy-Weinberg equation
the bottleneck effect - Correct Answer - A hurricane hits a small island, killing all
but a few members of a bird population. This is an example of __________.
Mutation - Correct Answer - Which of the following can form entirely new
alleles?
the expected frequency of the heterozygous genotype - Correct Answer - In the
Hardy-Weinberg equation, 2pq represents __________.
The expected frequency of the homozygous recessive genotype is represented by
q2.
The expected frequency of the homozygous dominant genotype is represented
by p2.
The expected frequency of the dominant allele is represented by p.
The expected frequency of the recessive allele is represented by q. - Correct
Answer - Hardy-Weinberg variables
Evolution is a change in a population's allele frequencies over generations. -
Correct Answer - In the context of populations, how do we define evolution?
Allele and genotype frequencies in the population will remain constant from
generation to generation. - Correct Answer - Which of the following statements
correctly describes a population in Hardy-Weinberg equilibrium?
Allele and genotype frequencies in the population will remain constant from
generation to generation.
All of the listed responses are correct.
The population is evolving.
The population exhibits no genetic variation.
,Allele and genotype frequencies in the population change from generation to
generation.
the reshuffling of alleles in sexual reproduction - Correct Answer - No two people
are genetically identical, except for identical twins. The main source of genetic
variation among human individuals is __________.
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 - Correct Answer - 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, __________.
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
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
t t t t t t t t t t t t
heterozygous genotype will remain the same, and the frequency of the homozygous
t t t t t t t t t t t t
recessives will go up
t t t t
, the frequency of the homozygous dominants will go down, the frequency of the
t t t t t t t t t t t t
heterozygous genotype will go down, and the frequency of the homozygous
t t t t t t t t t t t
recessives will go up
t t t t
.20 - Correct Answer - In a population that is in Hardy-Weinberg equilibrium, 64% of
t t tt t t t t t t t t t t t
the individuals express the recessive phenotype for a particular gene locus. What is
t t t t t t t t t t t t t
the expected frequency of the dominant allele in this population?
t t t t t t t t t t
the expected frequency of the homozygous recessive genotype - Correct Answer - In
t t t t t t t t t tt t t
the Hardy-Weinberg equation, q2 represents __________.
t t t t t t
Directional selection - Correct Answer - Antibiotic resistance in bacteria is an example
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of which of the following?
t t t t t
all copies of every type of allele at every locus in all members of the population -
t t t t t t t t t t t t t t t t
Correct Answer - The gene pool of a population consists of __________.
t tt t t t t t t t t t t
Disruptive selection - Correct Answer - A population of squirrels is preyed on by small
t t t tt t t t t t t t t t t
hawks. The smaller squirrels can escape into burrows. The larger squirrels can fight off
t t t t t t t t t t t t t t
the hawks. After several generations, the squirrels in the area tend to be very small or
t t t t t t t t t t t t t t t t
very large.
t t
What process is responsible for this outcome?
t t t t t t
the heterozygote advantage - Correct Answer - The sickle-cell allele, which is
t t t t tt t t t t t t
recessive, causes anemia but confers resistance to malaria in individuals who possess
t t t t t t t t t t t t
it. However, homozygous recessive individuals often die from anemia but not from
t t t t t t t t t t t t
malaria, and homozygous dominant individuals do not have anemia but could die
t t t t t t t t t t t t
from malaria. Heterozygous individuals have the highest relative fitness.
t t t t t t t t t
This is an example of __________.
t t t t t t
the homozygous recessive advantage
t t t
gene flow t
Whole-gene
The molecular level describes genetic variation as nucleotide variability.
Although populations do vary in their characteristics, it is at the gene level that
genetic variation can be quantified.
Although species do vary in their characteristics, it is at the gene level that
genetic variation can be quantified.
Individuals may vary in a population, but it is at the gene level that genetic
variation can be quantified. - Correct Answer - At what level does gene variability
quantify genetic variation?
Disruptive Selection
Disruptive selection favors individuals at both ends of the phenotypic spectrum. -
Correct Answer - 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?
natural selection - Correct Answer - All of the following conditions are required
for Hardy-Weinberg equilibrium except __________.
A large population is required for Hardy-Weinberg equilibrium.
A population without mutations is required for Hardy-Weinberg equilibrium.
,A population without gene flow is required for Hardy-Weinberg equilibrium.
Random mating in a population is required for Hardy-Weinberg equilibrium. -
Correct Answer - Conditions for the Hardy-Weinberg equation
the bottleneck effect - Correct Answer - A hurricane hits a small island, killing all
but a few members of a bird population. This is an example of __________.
Mutation - Correct Answer - Which of the following can form entirely new
alleles?
the expected frequency of the heterozygous genotype - Correct Answer - In the
Hardy-Weinberg equation, 2pq represents __________.
The expected frequency of the homozygous recessive genotype is represented by
q2.
The expected frequency of the homozygous dominant genotype is represented
by p2.
The expected frequency of the dominant allele is represented by p.
The expected frequency of the recessive allele is represented by q. - Correct
Answer - Hardy-Weinberg variables
Evolution is a change in a population's allele frequencies over generations. -
Correct Answer - In the context of populations, how do we define evolution?
Allele and genotype frequencies in the population will remain constant from
generation to generation. - Correct Answer - Which of the following statements
correctly describes a population in Hardy-Weinberg equilibrium?
Allele and genotype frequencies in the population will remain constant from
generation to generation.
All of the listed responses are correct.
The population is evolving.
The population exhibits no genetic variation.
,Allele and genotype frequencies in the population change from generation to
generation.
the reshuffling of alleles in sexual reproduction - Correct Answer - No two people
are genetically identical, except for identical twins. The main source of genetic
variation among human individuals is __________.
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 - Correct Answer - 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, __________.
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
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
t t t t t t t t t t t t
heterozygous genotype will remain the same, and the frequency of the homozygous
t t t t t t t t t t t t
recessives will go up
t t t t
, the frequency of the homozygous dominants will go down, the frequency of the
t t t t t t t t t t t t
heterozygous genotype will go down, and the frequency of the homozygous
t t t t t t t t t t t
recessives will go up
t t t t
.20 - Correct Answer - In a population that is in Hardy-Weinberg equilibrium, 64% of
t t tt t t t t t t t t t t t
the individuals express the recessive phenotype for a particular gene locus. What is
t t t t t t t t t t t t t
the expected frequency of the dominant allele in this population?
t t t t t t t t t t
the expected frequency of the homozygous recessive genotype - Correct Answer - In
t t t t t t t t t tt t t
the Hardy-Weinberg equation, q2 represents __________.
t t t t t t
Directional selection - Correct Answer - Antibiotic resistance in bacteria is an example
t t t tt t t t t t t t t
of which of the following?
t t t t t
all copies of every type of allele at every locus in all members of the population -
t t t t t t t t t t t t t t t t
Correct Answer - The gene pool of a population consists of __________.
t tt t t t t t t t t t t
Disruptive selection - Correct Answer - A population of squirrels is preyed on by small
t t t tt t t t t t t t t t t
hawks. The smaller squirrels can escape into burrows. The larger squirrels can fight off
t t t t t t t t t t t t t t
the hawks. After several generations, the squirrels in the area tend to be very small or
t t t t t t t t t t t t t t t t
very large.
t t
What process is responsible for this outcome?
t t t t t t
the heterozygote advantage - Correct Answer - The sickle-cell allele, which is
t t t t tt t t t t t t
recessive, causes anemia but confers resistance to malaria in individuals who possess
t t t t t t t t t t t t
it. However, homozygous recessive individuals often die from anemia but not from
t t t t t t t t t t t t
malaria, and homozygous dominant individuals do not have anemia but could die
t t t t t t t t t t t t
from malaria. Heterozygous individuals have the highest relative fitness.
t t t t t t t t t
This is an example of __________.
t t t t t t
the homozygous recessive advantage
t t t
gene flow t
