Chapter 26 Test Questions

Which of the following is NOT a step to calculate a coefficient of inbreeding? A. Determine the mutation rate. B. Determine the total number of common ancestors. C. Determine the shortest inbreeding path between the individual and the common ancestor. D. Calculate the inbreeding path for each common ancestor. E. Place values in the inbreeding coefficient formula.

A. Determine the mutation rate.

The characteristics of a given population over time are ________. A. Dynamic B. Static

A. Dynamic

Which of the following will alter the frequency of alleles in the population the least? A. Mutation B. Natural selection C. Genetic drift D. Migration E. All of the answers are equal

A. Mutation

A heterogeneous environment is typically a ______ factor against the fitness of the population. A. Negative B. Positive C. Neutral

A. Negative

The accumulation of new mutations in a population is usually a ______ factor against the fitness of the population. A. Negative B. Positive C. Neutral

A. Negative

Genetic drift has a greater influence on _____ populations. A. Small B. Large C. It affects both equally

A. Small

T or F? A gene that is found in less that 1% of a given population is called monomorphic.

False.

T or F? At equilibrium the allele and genotype frequencies of a population change over time.

False.

T or F? Horizontal gene transfer is limited to between prokaryotic bacteria of the same species.

False.

T or F? In the calculation of Hardy-Weinberg equilibria in the context of nonrandom mating, random mating is represented by the factor f equal to 1.

False.

T or F? Microsatellites and minisatellites are distinguished from each other by the number of repeats.

False.

T or F? Most natural populations are in a state of equilibrium according to Hardy-Weinberg.

False.

T or F? Mutations are the only source of genetic variation in a population.

False.

T or F? The allele pool is the sum of all of the alleles in a population.

False.

T or F? The movement of alleles from one population to another is called population flow.

False.

T or F? The selection coefficient is the measure to which a phenotype is selected against.

False.

T or F? Horizontal gene transfer between individuals in a population, while not a mutation, is a source of genetic variation.

True.

T or F? Human society favors outbreeding, or the mating of individuals that are genetically unrelated.

True.

T or F? In exon shuffling, the duplicated or rearranged exons appear as new domains in different genes.

True.

T or F? Microsatellites and minisatellites are distinguished from each other by the length of each repeating unit.

True.

T or F? Migration is a key evolution mechanism by which microevolution occurs.

True.

T or F? Neutral evolutionary forces alter allele frequencies in a random manner.

True.

T or F? New genetic variation in a population is a critical aspect of microevolution.

True.

T or F? Random genetic drift is due to chance events that alter the allele frequency in a population.

True.

T or F? The probability that a gene will be altered by a mutation is called the mutation rate.

True.

T or F? The smallest difference in DNA sequence between a gene in two individuals is a single-nucleotide polymorphism (SNP).

True.

T or F? The measure of the reproductive success of a genotype is called Darwinian fitness.

True.

The coefficient of inbreeding (F) tells us what about an individual? A. The probability that they are homozygous due to inheritance from a common ancestor B. Their genotype C. The probability of obtaining a certain allele from the gene pool

A. The probability that they are homozygous due to inheritance from a common ancestor

In a given population of Drosophila, curly wings (c) is recessive to the wild-type condition of straight wings (c+). You isolate a population of 35 curly winged flies, 70 flies that are heterozygous for straight wings and 45 that are homozygous for straight wings. What is the frequency of alleles in this population? A. 35% c; 45% c+ B. 46.7% c; 53.3% c+ C. 50% c; 50% c+ D. 55% c; 45% c+ E. The frequencies cannot be calculated from the provided information

B. 46.7% c; 53.3% c+

The prevalence of the allele for sickle cell anemia in some populations is an example of? A. Heterogeneous environments B. Balancing selection C. Inverted selection D. Non-Darwinian selection E. Nonrandom mating

B. Balancing selection

The formula p2 + 2pq + q2 = 1 is associated with which of the following? A. Calculations of heterozygosity B. Hardy-Weinberg equilibrium C. Calculations of recombination frequencies D. Degrees of freedom

B. Hardy-Weinberg equilibrium

In humans, the gene for eye color is an example of a ________ trait. A. Monomorphic B. Polymorphic

B. Polymorphic

A group of individuals from the same species that can interbreed with one another is the definition of a ________. A. Species B. Population C. Race D. Community E. Kingdom

B. Population

Which of the following types of selection favors the survival of individuals with the intermediate phenotype? A. Disruptive selection B. Stabilizing selection C. Directional selection

B. Stabilizing selection

If the allele frequency of the dominant allele is 0.4, what value is used for the term p2 in the equation p2 + 2pq + q2 = 1? A. 0.4 B. 0.2 C. 0.16 D. 16

C. 0.16

Which of the following factors would result in the allele frequency of a population not adding up to 1.0, as is the case in the Hardy-Weinberg rule? A. Genetic drift B. Inbreeding C. A population changing due to selection D. None of the answers, the allele frequencies must always equal 1.0

C. A population changing due to selection

A SNP would best be described as _____. A. A gene that comes in multiple different alleles B. A balanced polymorphism system C. A single nucleotide difference between two DNA sequences D. The most likely mutation to affect protein function

C. A single nucleotide difference between two DNA sequences

Which of the following types of selection favors one extreme of a phenotypic distribution? A. Disruptive selection B. Stabilizing selection C. Directional selection

C. Directional selection

If two individuals of a population, who vary in their phenotype, mate, it is called _____. A. Outbreeding B. Inbreeding C. Disassortative mating D. Assortative mating

C. Disassortative mating

Migration of a random few individuals from one population to a new area to establish a new population is an example of ____ A. Bottleneck effect B. Mutation C. Founder effect D. Selection

C. Founder effect

The degree of relatedness of two members of a pedigree is calculated using _____. A. The calculation of average heterozygosity B. The Hardy-Weinberg rule C. The coefficient of inbreeding D. The chi-square test

C. The coefficient of inbreeding

In this equation p2 + 2pq + q2 = 1, what does the term 2pq represent? A. The genotype frequency of homozygous recessive individuals B. The genotype frequency of homozygous dominant individuals C. The genotype frequency of heterozygous individuals D. The sum of the phenotype frequencies in the population

C. The genotype frequency of heterozygous individuals

In a given population of Drosophila, curly wings (c) is recessive to the wild-type condition of straight wings (c+). You isolate a population of 35 curly winged flies, 70 flies that are heterozygous for straight wings and 45 that are homozygous for straight wings. What is the total number of alleles in the gene pool? A. 2 B. 150 C. 230 D. 300 E. 140

D. 300

In a certain population, the frequency of allele A is 0.3 and the frequency of allele a is 0.7. The population inbreeds such that f = 0.1. What is the frequency of each genotype in the population? A. AA: 0.09, Aa: 0.42, aa: 0.49 B. AA: 0.49, Aa: 0.42, aa: 0.09 C. AA: 0.01, Aa: 0.90, aa: 0.09 D. AA: 0.111, Aa: 0.378, aa: 0.511 E. AA: 0.21, Aa: 0.42, aa: 0.37

D. AA: 0.111, Aa: 0.378, aa: 0.511

Which type of selection would lead to two distinct phenotypes? A. Stabilizing selection B. Phenotype selection C. Fitness selection D. Disruptive selection E. Directional selection

D. Disruptive selection

Which of the following is not true concerning a population in equilibrium according to the Hardy-Weinberg rule? A. There is no migration into or out of the population B. Individuals of the population mate randomly C. The population size is very large D. Selection is favoring the dominant allele E. There is no mutation in the populations

D. Selection is favoring the dominant allele

Which of the following is true regarding a balanced polymorphism? A. The frequency of alleles is not changing over time B. The homozygous condition for the alleles is not advantageous to the organism C. The population (or species) occupies a heterogeneous environment D. An example in humans is sickle-cell anemia E. All of the answers are correct

E. All of the answers are correct

Which of the following is NOT a characteristic by which a population is in equilibrium according to Hardy-Weinberg equation? A. The population is large. B. There is no migration into or out of the population. C. There is no selection against a given genotype. D. There is no mutation in the gene being studied. E. There is nonrandom mating

E. There is nonrandom mating