Question 1

Natural selection _______ on phenotypes and _______ on genotypes.

Accepted Answer

A)  can act directly; can act directly 
B)  can act directly; only acts indirectly 
C)  only acts indirectly; can act directly 
D)  only acts indirectly; only acts indirectly 
E)  None of the above; natural selection cannot act on phenotypes, either directly or indirectly. 
A)  can act directly; can act directly 
B)  can act directly; only acts indirectly 
C)  only acts indirectly; can act directly 
D)  only acts indirectly; only acts indirectly 
E)  None of the above; natural selection cannot act on phenotypes, either directly or indirectly.

Question 2

Which statement best exemplifies Lyell's ideas, which led Darwin to formulate his own views on evolution?

Accepted Answer

A)  Large-scale volcanic eruptions can quickly alter the landscape. 
B)  A catastrophic earthquake could almost instantaneously wipe out many species. 
C)  Coastline formation has occurred almost imperceptibly slowly, but it can operate over vast spans of time, even many millions of years. 
D)  Species of the temperate regions of South America are more similar to those of tropical South America than they are to temperate European species. 
E)  Species of the temperate regions of South America are more similar to temperate European species than they are to those of tropical South America. 
A)  Large-scale volcanic eruptions can quickly alter the landscape. 
B)  A catastrophic earthquake could almost instantaneously wipe out many species. 
C)  Coastline formation has occurred almost imperceptibly slowly, but it can operate over vast spans of time, even many millions of years. 
D)  Species of the temperate regions of South America are more similar to those of tropical South America than they are to temperate European species. 
E)  Species of the temperate regions of South America are more similar to temperate European species than they are to those of tropical South America.

Question 3

Which of the following can act as a constraint on the evolutionary process?

Accepted Answer

A)  The trade-off between the cost and benefit of an adaptation 
B)  The occurrence of rare catastrophic events, such as meteorite impacts 
C)  The fact that all evolutionary innovations are modifications of previously existing structures 
D)  Both a and c 
E)  All of the above 
A)  The trade-off between the cost and benefit of an adaptation 
B)  The occurrence of rare catastrophic events, such as meteorite impacts 
C)  The fact that all evolutionary innovations are modifications of previously existing structures 
D)  Both a and c 
E)  All of the above

Question 4

There are three isolated populations of orchids: population A has had a constant population size of about 40,000, population B has had a constant population size of about 14,000, and population C has had a constant population size of about 300.We would expect to see an increase in the frequency of deleterious alleles in population _______ because this population would experience the _______ genetic drift.

Accepted Answer

A)  A; most 
B)  A; least 
C)  B; most 
D)  C; most 
E)  C; least 
A)  A; most 
B)  A; least 
C)  B; most 
D)  C; most 
E)  C; least

Question 5

In a population of 300 panthers, there are _______ total copies of alleles for a single locus.

Accepted Answer

The answer of In a population of 300 panthers, there...

Question 6

Which understanding do modern biologists have that Darwin did not have?

Accepted Answer

A)  The tendency of individuals to resemble their parents 
B)  The common ancestry of species that exist today 
C)  The details of genetic inheritance 
D)  The operation of natural selection on changes in species over time 
E)  The greater similarity of species in temperate and tropical regions of South America than of species in temperate regions of South America and Europe 
A)  The tendency of individuals to resemble their parents 
B)  The common ancestry of species that exist today 
C)  The details of genetic inheritance 
D)  The operation of natural selection on changes in species over time 
E)  The greater similarity of species in temperate and tropical regions of South America than of species in temperate regions of South America and Europe

Question 7

In Mendel's peas, tall and short plant variants resulted from differences at a single genetic locus, with tall being dominant to short.The differences between the tall and short plants were caused by their different

Accepted Answer

A)  alleles. 
B)  gene pools. 
C)  alleles and genotypes. 
D)  alleles and gene pools. 
E)  None of the above 
A)  alleles. 
B)  gene pools. 
C)  alleles and genotypes. 
D)  alleles and gene pools. 
E)  None of the above

Question 8

High-throughput sequencing reveals that 30 new mutations have occurred in the coding regions of genes in an individual lizard.If the coding regions of this lizard comprise 150 million nucleotides per haploid genome, what is the mutation rate per nucleotide?

Accepted Answer

A)  2 per million 
B)  20 per billion 
C)  50 per billion 
D)  100 per billion 
E)  200 per billion 
A)  2 per million 
B)  20 per billion 
C)  50 per billion 
D)  100 per billion 
E)  200 per billion

Question 9

The numbers of fledged young of female swamp sparrows of different sizes were assayed and are presented in the table.   Assume that body size is at least partially heritable.What type of selection is most likely occurring in population B? Assume that all other aspects (survival, etc.) are independent of size.

Accepted Answer

A)  Stabilizing 
B)  Directional 
C)  Diversifying 
D)  Sexual 
E)  None of the above 
A)  Stabilizing 
B)  Directional 
C)  Diversifying 
D)  Sexual 
E)  None of the above

Question 10

You discover a population of mustard plants and find it to be at Hardy-Weinberg equilibrium with respect to the R locus.Suppose there are two alleles at this locus and the frequency of one of those alleles (the r-6 allele) is 0.2.Of the individuals that carry at least one r-6 allele, what fraction will be heterozygotes?

Accepted Answer

A)  1/9 
B)  1/5 
C)  1/3 
D)  4/5 
E)  8/9 
A)  1/9 
B)  1/5 
C)  1/3 
D)  4/5 
E)  8/9

Question 11

The table shows the number of offspring produced by genotype at the A locus in three different populations.Assuming all other things are equal, in which population(s) would you expect variation at the A locus to be maintained?

Accepted Answer

A)  Population 1 only 
B)  Population 2 only 
C)  Population 3 only 
D)  Both populations 1 and 2 
E)  Both populations 1 and 3 
A)  Population 1 only 
B)  Population 2 only 
C)  Population 3 only 
D)  Both populations 1 and 2 
E)  Both populations 1 and 3

Question 12

There are two isolated populations (A and B) of an endangered plant species.Population A has had a constant size of 2,000 plants, and population B has had a constant size of 250 plants.We most expect to see an increase in the frequency of deleterious alleles in population _______ due to _______.

Accepted Answer

A)  A; positive selection 
B)  A; genetic drift 
C)  B; positive selection 
D)  B; purifying selection 
E)  B; genetic drift 
A)  A; positive selection 
B)  A; genetic drift 
C)  B; positive selection 
D)  B; purifying selection 
E)  B; genetic drift

Question 13

If the frequency of the A3 allele of a creatine phosphatase locus in a population of lions is 0.4, how many copies of that allele should we expect to see in a population of 500 lions?

Accepted Answer

A)  100 
B)  200 
C)  400 
D)  500 
E)  600 
A)  100 
B)  200 
C)  400 
D)  500 
E)  600

Question 14

A sample of 200 individuals from a population of blister beetles has 105 individuals that are GG for the G locus, 70 that are Gg, and 25 that are gg.This means that the population

Accepted Answer

A)  has an excess of heterozygotes. 
B)  is in Hardy-Weinberg equilibrium. 
C)  has a deficiency of 7 percent heterozygotes. 
D)  has a deficiency of 14 percent heterozygotes. 
E)  has a deficiency of 20 percent heterozygotes. 
A)  has an excess of heterozygotes. 
B)  is in Hardy-Weinberg equilibrium. 
C)  has a deficiency of 7 percent heterozygotes. 
D)  has a deficiency of 14 percent heterozygotes. 
E)  has a deficiency of 20 percent heterozygotes.

Question 15

The numbers of fledged young of female song sparrows of different sizes were assayed and are presented in the table.   Assume that body size is at least partially heritable.Assume that all other aspects (survival, etc.) are independent of size.What type of selection, if any, is most likely occurring in population D? If selection is operating, what is the most likely effect of this selection on the phenotypic distribution?

Accepted Answer

Selection does not appear to b

Question 16

Polydactyly (having more than five fingers on a hand) is much more common in some isolated human populations than it is elsewhere.This is most likely an example of a(n) _______, which is due to the evolutionary mechanism called _______.

Accepted Answer

A)  founder effect; gene flow 
B)  founder effect; genetic drift 
C)  adaptation; gene flow 
D)  genetic ratchet; gene flow 
E)  genetic ratchet; genetic drift 
A)  founder effect; gene flow 
B)  founder effect; genetic drift 
C)  adaptation; gene flow 
D)  genetic ratchet; gene flow 
E)  genetic ratchet; genetic drift

Question 17

In a population of spiders, 40 percent of the individuals are homozygous for the A allele at a locus, and 20 percent are homozygous for the G allele at that locus.If A and G are the only alleles at the locus, then _______ percent of the population is heterozygous, which is ______ heterozygotes than would be expected under Hardy-Weinberg equilibrium.

Accepted Answer

A)  30; fewer 
B)  30; more 
C)  40; fewer 
D)  40; more 
E)  50; fewer 
A)  30; fewer 
B)  30; more 
C)  40; fewer 
D)  40; more 
E)  50; fewer

Question 18

The table lists the number of offspring produced, by genotype at the B locus, in three different populations.   Assuming all other things are equal, in which population(s) would you expect variation at the B locus to be maintained?

Accepted Answer

A)  Only population 1 
B)  Only population 2 
C)  Only population 3 
D)  Both populations 1 and 2 
E)  Both populations 1 and 3 
A)  Only population 1 
B)  Only population 2 
C)  Only population 3 
D)  Both populations 1 and 2 
E)  Both populations 1 and 3

Question 19

Which vegetable was produced from wild mustard, Brassica oleracea, through continued selection for larger stems and flowers?

Accepted Answer

A)  Kale 
B)  Brussels sprouts 
C)  Cabbage 
D)  Cauliflower 
E)  Broccoli 
A)  Kale 
B)  Brussels sprouts 
C)  Cabbage 
D)  Cauliflower 
E)  Broccoli

Question 20

High-throughput sequencing reveals that ten new mutations have occurred in the coding regions of genes in an individual bat.If the coding regions of this bat comprise 100 million nucleotides per haploid genome, what is the mutation rate per nucleotide?

Accepted Answer

A)  5 per billion 
B)  10 per billion 
C)  50 per billion 
D)  5 per million 
E)  10 per million 
A)  5 per billion 
B)  10 per billion 
C)  50 per billion 
D)  5 per million 
E)  10 per million

Exam 20: Mechanisms of Evolution

Natural selection _______ on phenotypes and _______ on genotypes.

Which statement best exemplifies Lyell's ideas, which led Darwin to formulate his own views on evolution?

Which of the following can act as a constraint on the evolutionary process?

In a population of 300 panthers, there are _______ total copies of alleles for a single locus.

Which understanding do modern biologists have that Darwin did not have?

In Mendel's peas, tall and short plant variants resulted from differences at a single genetic locus, with tall being dominant to short.The differences between the tall and short plants were caused by their different

High-throughput sequencing reveals that 30 new mutations have occurred in the coding regions of genes in an individual lizard.If the coding regions of this lizard comprise 150 million nucleotides per haploid genome, what is the mutation rate per nucleotide?

The table shows the number of offspring produced by genotype at the A locus in three different populations.Assuming all other things are equal, in which population(s) would you expect variation at the A locus to be maintained?

There are two isolated populations (A and B) of an endangered plant species.Population A has had a constant size of 2,000 plants, and population B has had a constant size of 250 plants.We most expect to see an increase in the frequency of deleterious alleles in population _______ due to _______.

If the frequency of the A3 allele of a creatine phosphatase locus in a population of lions is 0.4, how many copies of that allele should we expect to see in a population of 500 lions?

A sample of 200 individuals from a population of blister beetles has 105 individuals that are GG for the G locus, 70 that are Gg, and 25 that are gg.This means that the population

Polydactyly (having more than five fingers on a hand) is much more common in some isolated human populations than it is elsewhere.This is most likely an example of a(n) _______, which is due to the evolutionary mechanism called _______.

The table lists the number of offspring produced, by genotype at the B locus, in three different populations. Assuming all other things are equal, in which population(s) would you expect variation at the B locus to be maintained?

Which vegetable was produced from wild mustard, Brassica oleracea, through continued selection for larger stems and flowers?

High-throughput sequencing reveals that ten new mutations have occurred in the coding regions of genes in an individual bat.If the coding regions of this bat comprise 100 million nucleotides per haploid genome, what is the mutation rate per nucleotide?

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinant Dna and Biotechnology

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons, Glia, and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Functions

Musculoskeletal Systems

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Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

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A Changing Biosphere

Filters

Natural selection _ on phenotypes and _ on genotypes.

There are two isolated populations (A and B) of an endangered plant species.Population A has had a constant size of 2,000 plants, and population B has had a constant size of 250 plants.We most expect to see an increase in the frequency of deleterious alleles in population _ due to _.

Polydactyly (having more than five fingers on a hand) is much more common in some isolated human populations than it is elsewhere.This is most likely an example of a(n) _, which is due to the evolutionary mechanism called _.