Deck 23: Population Genetics

Question 1

The frequency of sickle cell anemia,caused by a homozygous condition (Hb?Hb?)is approximately 0.0016.The normal condition is also a homozygous condition (Hb?Hb?).Assuming the Hardy-Weinberg equilibrium applies,what is the frequency of the Hb? allele?

A) 0.0004
B) 0.04
C) 0.4
D) 0.9216
E) 0.96

Answer 1

E

Question 2

The frequency of sickle cell anemia,caused by a homozygous condition (Hb?Hb?)is approximately 0.0016.The normal condition is also a homozygous condition (Hb?Hb?).Assuming the Hardy-Weinberg equilibrium applies,what is the frequency of the carrier state (Hb?Hb?)?

A) 0.0228
B) 0.0432
C) 0.0768
D) 0.0987
E) 0.0384

Answer 2

C

Question 3

Which of the following is a force that could upset the Hardy-Weinberg equilibrium?

A) Mutation
B) Migration
C) Natural selection
D) Genetic drift
E) All of these

Answer 3

E

Question 4

In a sample of 400 men,48 have X-linked color blindness and all the others have normal color vision.If men are hemizygous for the allele,what is the frequency for the X-linked color blindness allele?

A) 0.1
B) 0.12
C) 0.24
D) 0.48
E) 0.88

Question 5

In a sample of 600 individuals (400 men and 200 women)48 men have X-linked color blindness (X?)and all the others have normal color vision (X?).What is the frequency of women who are carriers?

A) 0.12
B) 0.88
C) 0.346
D) 0.02
E) 0.21

Question 6

Which of the following is a key assumption underlying the Hardy-Weinberg principle?
1)The members of the population mate at random with respect to the gene under study.
2)The members of the population are artificially selected with respect to the gene under study.
3)The members of the population must live on an island.

A) 1
B) 2
C) 3
D) 1 and 3
E) 2 and 3

Question 7

The A-B-O blood types are determined by three alleles I?,I?,and i.In one population the frequency of individuals who are homozygous for type A blood is 0.063,the frequency of individuals who are homozygous for type B blood is 0.015,and the frequency of individuals who are blood type O is 0.44.What is the frequency of individuals are blood type AB?

A) 0.251
B) 0.122
C) 0.031
D) 0.061
E) 0.5

Question 8

Which of the following can be calculated using a major population genetics theory?
1)The frequency of homozygous dominant and recessive individuals
2)The frequency of heterozygous individual
3)The frequency of a dominant allele

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 9

The frequency of sickle cell anemia,caused by a homozygous condition (Hb?Hb?)is approximately 0.0016.Assuming the Hardy-Weinberg equilibrium applies,what is the frequency of the Hb? allele?

A) 0.01
B) 0.00008
C) 0.08
D) 0.04
E) 0.4

Question 10

There are 300 individuals in sample group #1 taken from population X.Seventy-five individuals of sample group are homozygous for the trait in question (I?I?).Seventy five individuals are homozygous for the trait (I?I?).Everyone else is heterozygous (I?I?)for the trait.What is the frequency of allele A in the sample group,assuming the trait is controlled by a single gene?

A) 0
B) 0.375
C) 0.5
D) 0.75
E) 1

Question 11

There are 300 individuals in sample group #1 taken from population X.How many total alleles for the trait in question are present in the sample group,assuming the trait is controlled by a single codominant gene?

A) 150
B) 300
C) 600
D) 900
E) 1200

Question 12

In a population,whenever the second most frequent allele of a gene has a frequency greater than 0.01,we refer to the situation as a

A) genetic polymorphism.
B) genetic anomaly.
C) genetic mutation.
D) genetic abnormality.
E) None of these

Question 13

In a sample of 600 individuals (400 men and 200 women)48 men have X-linked color blindness (X?)and all the others have normal color vision (X?).What is the frequency of women who are colorblind? A)0.12
B)0)88
C)0)346
D)0)02
E)0)21

Question 14

In a sample of 500 men,240 have X-linked hemophilia and all the others have normal blood clotting.If men are hemizygous for the allele,what is the frequency for the X-linked hemophilia allele?

A) 0.1
B) 0.12
C) 0.24
D) 0.48
E) 0.88

Question 15

There are 300 individuals in sample group #1 taken from population X.Seventy-five individuals of sample group are homozygous for the trait in question (I?I?).Seventy five individuals are homozygous for the trait (I?I?).Everyone else is heterozygous (I?I?)for the trait.What is the frequency of allele B in the sample group,assuming the trait is controlled by a single gene?

A) 0
B) 0.375
C) 0.5
D) 0.75
E) 1

Question 16

Which of the following is true regarding determining the number of alleles in a population sample? 1.It may be impossible to count the number of alleles if one allele is dominant.
2)When counting X-linked alleles it is only important to count the different alleles in males.
3)Codominant alleles can always be counted because they produce unique phenotypes.

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 17

What is explained by a major population genetics theory?
1)The number of individuals in a population
2)The allelic frequencies within a population
3)The number of individuals outside a population

A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question 18

Which of the following individuals described a mathematical relationship between allele frequencies and genotype frequencies?

A) G.H. Hardy
B) Wilhelm Weinberg
C) Edward East
D) G.H. Hardy and Wilhelm Weinberg
E) Wilhelm Weinberg and Edward East

Question 19

Which of the following allows one to predict a population's genotype frequencies from its allele frequencies?

A) Hardy-Weinberg principle
B) East-Hayflick principle
C) Hooke-Van Leuwenhoek principle
D) Morgan-Hunt principle
E) None of these

Question 20

Which of the following accurately describes the Hardy-Weinberg genotype frequency expression?

A) P² + 2p +q²
B) P² + 2pq + q³
C) P²+2pq+q²
D) P³ + 3pq+q³
E) (p+q)³

Question 21

What general effect does random genetic drift have on populations?
1)It reduces the dominant homozygosity.
2)It reduces the heterozgosity.
3)It reduces the recessive homozygosity.

A) 1
B) 2
C) 3
D) 1 and 3
E) All of these

Question 22

What causes allele frequencies to change unpredictably in populations because of reproductive uncertainties?

A) Random genetic abnormalities
B) Random genetic drift
C) Random mating
D) Natural selection
E) Artificial selection

Question 23

Which of the following is a type of non-random mating?

A) Consanguinous mating
B) Assortative mating
C) Discoursive mating
D) Consanguinous mating and assortative mating
E) Assortative mating and discoursive mating

Question 24

Which assumption of the Hardy-Weinberg principle is violated by the concept of population subdivision?

A) Random-mating
B) Allele frequencies are uniform throughout the population
C) Individuals are diploid
D) Individuals are haploid
E) None of these

Question 25

Selection that favors intermediate values of a trait at the expense of extreme values is known as

A) directional selection.
B) disruptive selection.
C) stabilizing selection.
D) directional selection and disruptive selection.
E) All of these

Question 26

The A-B-O blood types are determined by three alleles I?,I?,and i.In one population the frequency of individuals who are homozygous for type A blood is 0.063,the frequency of individuals who are homozygous for type B blood is 0.015,and the frequency of individuals who are blood type O is 0.44.What is the frequency of the i allele?

A) 0.251
B) 0.663
C) 0.166
D) 0.333
E) 0.061

Question 27

When a population is a single interbreeding unit,it is said to be

A) panmitic.
B) non-panmitic.
C) heterozygous.
D) homozygous.
E) None of these

Question 28

Which of the following prevent the Hardy-Weinberg principle from applying to a population?

A) The population experiences random mating for the gene in question.
B) The zygotes produced by random mating have different survival rates.
C) The population is panmitic.
D) The population is not subject to migration.
E) All of these

Question 29

At the level of the phenotype,natural selection influences the

A) distribution of alleles.
B) distribution of quantitative traits.
C) distribution of genotypes.
D) distribution of alleles and distribution of genotypes.
E) None of these

Question 30

Which of the following occurs when genotypes differ in the ability to survive and reproduce?

A) Unequal population division
B) Population subdivision
C) Natural selection
D) Inbreeding
E) None of these

Question 31

Which of the following is most effective at fixing the recessive allele in a population?

A) Selection for a recessive allele
B) Selection against a recessive allele
C) Selection against homozygous recessive individuals
D) Selection against heterozygotes
E) All of these

Question 32

At the level of the gene,natural selection changes the frequencies of

A) genotypes in biomes.
B) genotypes in populations.
C) alleles in biomes.
D) alleles in populations.
E) All of these

Question 33

What effect does consanguineous mating and assortative mating have on genotypic frequencies in populations?
1)Reduce the frequency of homozyotes
2)Increase the frequency of homozygotes
3)Reduce the frequency of heterozygotes

A) 1
B) 2
C) 3
D) 1 and 3
E) 2 and 3

Question 34

The A-B-O blood types are determined by three alleles I?,I?,and i.In one population the frequency of individuals who are homozygous for type A blood is 0.063,the frequency of individuals who are homozygous for type B blood is 0.015,and the frequency of individuals are blood type O is 0.44.What is the frequency of individuals who are heterozygous for type A blood?

A) 0.251
B) 0.663
C) 0.166
D) 0.333
E) 0.061

Question 35

The intensity of natural selection is quantified by the

A) correlation coefficient.
B) selection coefficient.
C) cosanguinous coefficient.
D) fitness number.
E) All of these

Question 36

Selection that favors extreme values of a trait at the expense of intermediate values is known as

A) directional selection.
B) disruptive selection.
C) stabilizing selection.
D) directional selection and disruptive selection.
E) All of these

Question 37

In a population that experiences migration (i.e.the merging of two separate populations),why are observed allelic and genotypic frequencies different than what is predicted by the Hardy-Weinberg equilibrium?

A) The observed genotype frequencies were not created by random mating within the entire merged population.
B) The observed genotype frequencies were created by random mating within the entire merged population.
C) The observed genotype frequencies were subject to inbreeding.
D) The populations experienced unequal survival rates.
E) None of these

Question 38

What is the ultimate source of all genetic variability?

A) Natural selection
B) Artificial selection
C) Mutation
D) Natural selection and artificial selection
E) None of these

Question 39

How does random genetic drift affect large populations?

A) It may be the primary evolutionary force.
B) It has a moderate effect.
C) It has very little effect.
D) It is not currently known what kind of effect it has on large populations.
E) It does not affect large populations at all.

Question 40

Which type of selection can affect the distribution of a quantitative trait?

A) Directional selection
B) Disruptive selection
C) Stabilizing selection
D) Directional selection and Disruptive selection
E) All of these

Question 41

There are 800 individuals in sample group #1 taken from population X that were examined to the codominant trait R.When sampled 30 individuals were homozygous for allele Z (R?R?),100 individuals were homozygous for allele K (R?R?)and the rest were heterozygous (R?R?)).Determine how many total alleles for the trait in question are present in the sample group,the frequency of allele Z,and the frequency of allele Q,assuming the trait is controlled by a single codominant gene?

Question 42

In diploid organisms,the rate at which genetic variability is lost by random genetic drift is

A) 1/2N, where N is the population size.
B) 1/3N, where N is the population size.
C) 1/4N, where N is the population size.
D) 1/5N, where N is the population size.
E) None of these

Question 43

In a sample of 3000 individuals,1000 men and 2000 women,200 men have hemophilia and all the others have normal clotting function.All the women have normal clotting function.What are the frequencies for the hemophilia allele (X?)and normal allele (X?)?

Question 44

Selection against a deleterious recessive allele is replenished in the population by mutation,and leads to a dynamic equilibrium in which the frequency of the recessive allele is a simple function of the mutation rate and the selection coefficient.Which formula represents this situation?

A) p²+2pq+q²
B)
C)
D) 1/2N
E) None of these

Question 45

The A-B-O blood types are determined by three alleles I?,I?,and i.In a population the frequency of individuals who are homozygous for type A blood is 0.063,the frequency of individuals who are homozygous for type B blood is 0.015,and the frequency of individuals are blood type O is 0.44.What is the frequency of all genotypes?

Question 46

Which type of selection creates a dynamic equilibrium in which different alleles are retained in a population despite their being harmful in homozygotes?

A) Balancing selection
B) Disruptive selection
C) Stabilizing selection
D) Directional selection
E) None of these

Question 47

A population's acquisition of selectively neutral alleles through mutation is balanced by the loss of these alleles through genetic drift.At equilibrium,the frequency of heterozygotes involving these alleles is a function of the population's size and the mutation rate is

A) p²+2pq+q²
B)
C)
D) 1/2N
E) None of these

Question 48

Which of the following human diseases is associated with balancing selection?

A) Tay Sachs
B) Down Syndrome
C) Sickle Cell Anemia
D) Lesch-Nyhan Syndrome
E) Alzheimers Disease

Question 49

The frequency of cystic fibrosis found in those of European descent,caused by a homozygous recessive gene is approximately 0.04.Assuming the Hardy-Weinberg equilibrium applies,what are the frequencies of the recessive/affected allele,the dominant/normal allele,the homozygous normal condition,and the carrier/heterozygous genotype?

Question 50

What type of selection is demonstrated by the following chart?