Question 1

The Hardy-Weinberg equilibrium theorem

Accepted Answer

A) applies to extremely small populations that are subject to genetic drift. 
B) describes two or more populations that interbreed with one another. 
C) applies to populations that exhibit low rates of mutation. 
D) describes a hypothetical population that is not evolving. 
E) applies to populations that show differential survival and reproductive success. 
A) applies to extremely small populations that are subject to genetic drift. 
B) describes two or more populations that interbreed with one another. 
C) applies to populations that exhibit low rates of mutation. 
D) describes a hypothetical population that is not evolving. 
E) applies to populations that show differential survival and reproductive success.

Question 2

In the formula for determining a population's genotype frequencies,the 2 in the term 2pq is necessary because

Accepted Answer

A) the population is diploid. 
B) heterozygotes can come about in two ways. 
C) the population is doubling in number. 
D) heterozygotes have two alleles. 
A) the population is diploid. 
B) heterozygotes can come about in two ways. 
C) the population is doubling in number. 
D) heterozygotes have two alleles.

Question 3

Use the following information to answer the questions below.
In the year 2500,five male space colonists and five female space colonists (all unrelated to each other)settle on an uninhabited Earthlike planet in the Andromeda galaxy.The colonists and their offspring randomly mate for generations.All ten of the original colonists had free earlobes,and two were heterozygous for that trait.The allele for free earlobes is dominant to the allele for attached earlobes.
-If one assumes that Hardy-Weinberg equilibrium applies to the population of colonists on this planet,about how many people will have attached earlobes when the planet's population reaches 10000?

Accepted Answer

A) 100 
B) 400 
C) 800 
D) 1000 
E) 10 000 
A) 100 
B) 400 
C) 800 
D) 1000 
E) 10 000

Question 4

Use the following figure to answer the questions below.
In a very large population,a quantitative trait has the following distribution pattern:
  
-What would be the most probable cause for a population depicted in the figure above to shift both to the left and to the right?

Accepted Answer

A) when large size is important 
B) when there is an extreme environmental change 
C) when there are few predators 
D) when there are differences in the size of food items available to members of the same species 
E) when the more common alleles are lost 
A) when large size is important 
B) when there is an extreme environmental change 
C) when there are few predators 
D) when there are differences in the size of food items available to members of the same species 
E) when the more common alleles are lost

Question 5

What is true of natural selection?

Accepted Answer

A) Natural selection is a random process. 
B) Natural selection creates beneficial mutations. 
C) The only way to eliminate harmful mutations is through natural selection. 
D) Mutations occur at random; natural selection can preserve and distribute beneficial mutations. 
E) Mutations occur when directed by the good of the species; natural selection edits out harmful mutations and causes populations to adapt to the beneficial mutations. 
A) Natural selection is a random process. 
B) Natural selection creates beneficial mutations. 
C) The only way to eliminate harmful mutations is through natural selection. 
D) Mutations occur at random; natural selection can preserve and distribute beneficial mutations. 
E) Mutations occur when directed by the good of the species; natural selection edits out harmful mutations and causes populations to adapt to the beneficial mutations.

Question 6

The following questions refer to the following paragraph.
HIV's genome of RNA includes the code for reverse transcriptase (RT),an enzyme that acts early in infection to synthesize a DNA genome from an RNA template.The HIV genome also codes for protease (PR),an enzyme that acts later in infection by cutting long viral polyproteins into smaller,functional proteins.Both RT and PR represent potential targets for antiretroviral drugs.Drugs called nucleoside analogues (NA)act against RT,whereas drugs called protease inhibitors (PI)act against PR.
-In a hypothetical population's gene pool,an autosomal gene,which had previously been fixed,undergoes a mutation that introduces a new allele,one inherited according to incomplete dominance.Natural selection then causes stabilizing selection at this locus.Consequently,what should happen over the course of many generations?

Accepted Answer

A) The proportions of both types of homozygote should decrease. 
B) The proportion of the population that is heterozygous at this locus should remain constant. 
C) The population's average heterozygosity should decrease. 
D) The two homozygotes should decrease at different rates. 
A) The proportions of both types of homozygote should decrease. 
B) The proportion of the population that is heterozygous at this locus should remain constant. 
C) The population's average heterozygosity should decrease. 
D) The two homozygotes should decrease at different rates.

Question 7

How many of these statements regarding populations are true?
1)Mature males and females of a population can interbreed with each other.
2)Populations are sometimes geographically isolated from other populations.
3)Biological species are made up of populations.
4)Members of a population tend to be genetically more similar to each other than to members of other populations.
5)Populations have genomes,but not gene pools.

Accepted Answer

A) Only one of these statements is true. 
B) Two of these statements are true. 
C) Three of these statements are true. 
D) Four of these statements are true. 
E) All five of these statements are true. 
A) Only one of these statements is true. 
B) Two of these statements are true. 
C) Three of these statements are true. 
D) Four of these statements are true. 
E) All five of these statements are true.

Question 8

Which statement about variation is true?

Accepted Answer

A) All phenotypic variation is the result of genotypic variation. 
B) All genetic variation produces phenotypic variation. 
C) All nucleotide variability results in neutral variation. 
D) All new alleles are the result of nucleotide variability. 
E) All genetic variation is dependent on environmental stimuli. 
A) All phenotypic variation is the result of genotypic variation. 
B) All genetic variation produces phenotypic variation. 
C) All nucleotide variability results in neutral variation. 
D) All new alleles are the result of nucleotide variability. 
E) All genetic variation is dependent on environmental stimuli.

Question 9

Use the following information to answer the questions below.
In those parts of equatorial Africa where the malaria parasite is most common,the sickle-cell allele constitutes 20% of the β hemoglobin alleles in the human gene pool.
-With respect to the sickle-cell allele,what should be true of the β hemoglobin locus in U.S.populations of African-Americans whose ancestors were from equatorial Africa?
1)The average heterozygosity at this locus should be decreasing over time.
2)There is an increasing heterozygote advantage at this locus.
3)Diploidy is helping to preserve the sickle-cell allele at this locus.
4)Frequency-dependent selection is helping to preserve the sickle-cell allele at this locus.

Accepted Answer

A) 1 only 
B) 1 and 3 
C) 2 and 3 
D) 1, 2, and 3 
E) 1, 2, and 4 
A) 1 only 
B) 1 and 3 
C) 2 and 3 
D) 1, 2, and 3 
E) 1, 2, and 4

Question 10

Which of the following is a fitness trade-off (compromise)?

Accepted Answer

A) In some hornbill species, the male helps seal the female in a tree with her nest until the young are ready to fledge. 
B) Hummingbirds are the best pollinators of certain flowers, but bees are the best pollinators for orchids. 
C) The strong, thick beak of a woodpecker helps it find insects in trees. 
D) Turtle shells provide protection but are heavy and burdensome when moving. 
E) Fruit bats are better pollinators of native fruit trees than birds are. 
A) In some hornbill species, the male helps seal the female in a tree with her nest until the young are ready to fledge. 
B) Hummingbirds are the best pollinators of certain flowers, but bees are the best pollinators for orchids. 
C) The strong, thick beak of a woodpecker helps it find insects in trees. 
D) Turtle shells provide protection but are heavy and burdensome when moving. 
E) Fruit bats are better pollinators of native fruit trees than birds are.

Question 11

Little nucleotide variability results in phenotypic variation because

Accepted Answer

A) many of the differences are masked. 
B) nucleotide variability is not expressed as often as gene variability. 
C) many of the differences occur within introns. 
D) many of the differences occur within exons. 
E) nucleotide variability depends on the environment. 
A) many of the differences are masked. 
B) nucleotide variability is not expressed as often as gene variability. 
C) many of the differences occur within introns. 
D) many of the differences occur within exons. 
E) nucleotide variability depends on the environment.

Question 12

You are shown caterpillars of the moth Nemoria arizonaria.The caterpillars belong to the same species,but some of the caterpillars that were collected from oak flowers resemble oak flowers,while caterpillars collected from oak twigs resemble oak twigs.What is the most plausible explanation for the phenotypic variation?

Accepted Answer

A) Some of the caterpillars had a mutation that changed the genotype and phenotype. 
B) The phenotypic variation appears to be influenced by the environment/diet. 
C) Variation among individuals in this species is common, but over time one phenotype will outcompete the other phenotype. 
D) The variation is due to heterozygote protection. 
E) More data needs to be collected. 
A) Some of the caterpillars had a mutation that changed the genotype and phenotype. 
B) The phenotypic variation appears to be influenced by the environment/diet. 
C) Variation among individuals in this species is common, but over time one phenotype will outcompete the other phenotype. 
D) The variation is due to heterozygote protection. 
E) More data needs to be collected.

Question 13

Use the following figure to answer the questions below.
In a very large population,a quantitative trait has the following distribution pattern:
  
-What is true of the trait whose frequency distribution in a large population appears in the previous figure? It has probably undergone

Accepted Answer

A) directional selection. 
B) stabilizing selection. 
C) disruptive selection. 
D) normal selection. 
A) directional selection. 
B) stabilizing selection. 
C) disruptive selection. 
D) normal selection.

Question 14

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true?

Accepted Answer

A) Each bird evolved a deeper, stronger beak as the drought persisted. 
B) Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted. 
C) Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation. 
D) The frequency of the strong-beak alleles increased in each bird as the drought persisted. 
A) Each bird evolved a deeper, stronger beak as the drought persisted. 
B) Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted. 
C) Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation. 
D) The frequency of the strong-beak alleles increased in each bird as the drought persisted.

Question 15

In a Hardy-Weinberg population with two alleles,A and a,that are in equilibrium,the frequency of allele a is 0.2.What is the percentage of the population that is heterozygous for this allele?

Accepted Answer

A) 0)2 
B) 2)0 
C) 4)0 
D) 16.0 
E) 32.0 
A) 0)2 
B) 2)0 
C) 4)0 
D) 16.0 
E) 32.0

Question 16

If global warming permits mosquitoes to live at higher altitudes than they currently do,then in which direction should the entire plot in the correct distribution below be shifted?
a)  
b)  
c)  
d)

Accepted Answer

A) to the right 
B) to the left 
C) upward 
D) downward 
A) to the right 
B) to the left 
C) upward 
D) downward

Question 17

In the wild,male house finches (Carpodus mexicanus)vary considerably in the amount of red pigmentation in their head and throat feathers,with colours ranging from pale yellow to bright red.These colours come from carotenoid pigments that are found in the birds' diets; no vertebrates are known to synthesize carotenoid pigments.Thus,the brighter red the male's feathers are,the more successful he has been at acquiring the red carotenoid pigment by his food-gathering efforts (all other factors being equal).During breeding season,one should expect female house finches to prefer to mate with males with the brightest red feathers.Which of the following is true of this situation?

Accepted Answer

A) Alleles that promote more efficient acquisition of carotenoid-containing foods by males should increase over the course of generations. 
B) Alleles that promote more effective deposition of carotenoid pigments in the feathers of males should increase over the course of generations. 
C) There should be directional selection for bright red feathers in males. 
D) Three of the statements are correct. 
E) Two of the statements are correct. 
A) Alleles that promote more efficient acquisition of carotenoid-containing foods by males should increase over the course of generations. 
B) Alleles that promote more effective deposition of carotenoid pigments in the feathers of males should increase over the course of generations. 
C) There should be directional selection for bright red feathers in males. 
D) Three of the statements are correct. 
E) Two of the statements are correct.

Question 18

There are 40 individuals in population 1,all with genotype A1A1,and there are 25 individuals in population 2,all with genotype A2A2.Assume that these populations are located far from each other and that their environmental conditions are very similar.Based on the information given here,the observed genetic variation is most likely an example of

Accepted Answer

A) genetic drift. 
B) gene flow. 
C) disruptive selection. 
D) discrete variation. 
E) directional selection. 
A) genetic drift. 
B) gene flow. 
C) disruptive selection. 
D) discrete variation. 
E) directional selection.

Question 19

Most Swiss starlings produce four to five eggs in each clutch.Starlings producing fewer,or more,than this have reduced fitness.Which of the following terms best describes this situation?

Accepted Answer

A) artificial selection 
B) directional selection 
C) stabilizing selection 
D) disruptive selection 
E) sexual selection 
A) artificial selection 
B) directional selection 
C) stabilizing selection 
D) disruptive selection 
E) sexual selection

Question 20

You sample a population of butterflies and find that 56% are heterozygous at a particular locus.What should be the frequency of the recessive allele in this population?

Accepted Answer

A) 0)07 
B) 0)08 
C) 0)09 
D) 0)70 
E) Allele frequency cannot be determined from this information. 
A) 0)07 
B) 0)08 
C) 0)09 
D) 0)70 
E) Allele frequency cannot be determined from this information.

Exam 23: The Evolution of Populations

The Hardy-Weinberg equilibrium theorem

In the formula for determining a population's genotype frequencies,the 2 in the term 2pq is necessary because

Use the following figure to answer the questions below. In a very large population,a quantitative trait has the following distribution pattern: -What would be the most probable cause for a population depicted in the figure above to shift both to the left and to the right?

What is true of natural selection?

Which statement about variation is true?

Which of the following is a fitness trade-off (compromise)?

Little nucleotide variability results in phenotypic variation because

Use the following figure to answer the questions below. In a very large population,a quantitative trait has the following distribution pattern: -What is true of the trait whose frequency distribution in a large population appears in the previous figure? It has probably undergone

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true?

In a Hardy-Weinberg population with two alleles,A and a,that are in equilibrium,the frequency of allele a is 0.2.What is the percentage of the population that is heterozygous for this allele?

If global warming permits mosquitoes to live at higher altitudes than they currently do,then in which direction should the entire plot in the correct distribution below be shifted? a) b) c) d)

Most Swiss starlings produce four to five eggs in each clutch.Starlings producing fewer,or more,than this have reduced fitness.Which of the following terms best describes this situation?

You sample a population of butterflies and find that 56% are heterozygous at a particular locus.What should be the frequency of the recessive allele in this population?

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure,Growth,and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons,Synapses,and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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