Question 1

Speciation is an important component of evolution because it

Accepted Answer

A)  generates the variation on which natural selection acts. 
B)  generates the variation on which genetic drift and mutations act. 
C)  enabled Charles Darwin to perceive the mechanisms of evolution. 
D)  generates the high extinction rates that drive evolutionary change. 
E)  has resulted in a world with millions of species, each adapted for a particular way of life. 
A)  generates the variation on which natural selection acts. 
B)  generates the variation on which genetic drift and mutations act. 
C)  enabled Charles Darwin to perceive the mechanisms of evolution. 
D)  generates the high extinction rates that drive evolutionary change. 
E)  has resulted in a world with millions of species, each adapted for a particular way of life.

Question 2

The Isthmus of Panama cut off gene flow between Atlantic and Pacific populations of a species of fish. The cessation of gene flow led to the accumulation of genetic differences between the populations, which led to reproductive isolation. Now Atlantic and Pacific populations of this fish are separate species that cannot interbreed, even if they were again to come into contact with each other. The process described is that of

Accepted Answer

A)  sympatric speciation. 
B)  parapatric speciation. 
C)  allopatric speciation. 
D)  reinforcement. 
E)  temporal isolation. 
A)  sympatric speciation. 
B)  parapatric speciation. 
C)  allopatric speciation. 
D)  reinforcement. 
E)  temporal isolation.

Question 3

Suppose the hybrids of two salamander species exhibit reduced adult viability. These species would thus have a _______ reproductive isolating barrier.

Accepted Answer

The answer of Suppose the hybrids of two salamander species...

Question 4

Which of the following is a major limitation of the morphological species concept?

Accepted Answer

A)  It requires detailed knowledge of genetics and mating behavior. 
B)  Males and females of a single species do not necessarily look alike. 
C)  It is a very recent concept. 
D)  It is incompatible with the binomial system of classification. 
E)  It cannot be used in field guides. 
A)  It requires detailed knowledge of genetics and mating behavior. 
B)  Males and females of a single species do not necessarily look alike. 
C)  It is a very recent concept. 
D)  It is incompatible with the binomial system of classification. 
E)  It cannot be used in field guides.

Question 5

Which type of speciation is most common among flowering plants?

Accepted Answer

A)  Geographic 
B)  Sympatric 
C)  Allopatric 
D)  Disruptive 
E)  None of the above 
A)  Geographic 
B)  Sympatric 
C)  Allopatric 
D)  Disruptive 
E)  None of the above

Question 6

Which of the following factors would not be expected to increase the rate of speciation in a group of organisms?

Accepted Answer

A)  Fragmentation of populations 
B)  Poor dispersal ability 
C)  High birthrates 
D)  Dietary specialization 
E)  Pollination by animals 
A)  Fragmentation of populations 
B)  Poor dispersal ability 
C)  High birthrates 
D)  Dietary specialization 
E)  Pollination by animals

Question 7

Which of the following adaptations is not found among any of the species of Darwin's finches?

Accepted Answer

A)  Large bills for crushing large, hard seeds 
B)  Beaks that can open cactus fruits and extract the seeds 
C)  Long beaks for probing dead wood, crevices, and bark for insects 
D)  Heavy bills for twisting apart wood to reach larvae inside 
E)  None of the above; all of the adaptations are observed in these birds. 
A)  Large bills for crushing large, hard seeds 
B)  Beaks that can open cactus fruits and extract the seeds 
C)  Long beaks for probing dead wood, crevices, and bark for insects 
D)  Heavy bills for twisting apart wood to reach larvae inside 
E)  None of the above; all of the adaptations are observed in these birds.

Question 8

More than 800 species of Drosophila occur in the Hawaiian Islands, representing 30 to 40 percent of all the species in this genus. The occurrence of so many Drosophila species in this island chain is

Accepted Answer

A)  the result of many founder events followed by genetic divergence. 
B)  an example of an evolutionary radiation. 
C)  largely the result of sympatric speciation. 
D)  evidence that the genus Drosophila first evolved in the Hawaiian Islands. 
E)  Both a and b 
A)  the result of many founder events followed by genetic divergence. 
B)  an example of an evolutionary radiation. 
C)  largely the result of sympatric speciation. 
D)  evidence that the genus Drosophila first evolved in the Hawaiian Islands. 
E)  Both a and b

Question 9

Which of the following statements about speciation is true?

Accepted Answer

A)  Wind-pollinated plants typically have higher speciation rates than animal-pollinated plants. 
B)  Species that move have higher rates of speciation than those with limited dispersal. 
C)  Sexual selection seems to decrease speciation rates. 
D)  Herbivorous insects typically have higher rates of speciation compared with insects that prey on other insects. 
E)  None of the above 
A)  Wind-pollinated plants typically have higher speciation rates than animal-pollinated plants. 
B)  Species that move have higher rates of speciation than those with limited dispersal. 
C)  Sexual selection seems to decrease speciation rates. 
D)  Herbivorous insects typically have higher rates of speciation compared with insects that prey on other insects. 
E)  None of the above

Question 10

A field contains two related species of flowering plants. Species A has a diploid chromosome number of 16, and species B has a diploid number of 18. If a third species arises as a result of hybridization between A and B, how many chromosomes will it have?

Accepted Answer

A)  17 
B)  32 
C)  34 
D)  36 
E)  68 
A)  17 
B)  32 
C)  34 
D)  36 
E)  68

Question 11

What is the critical distinction between allopolyploidy and autopolyploidy?

Accepted Answer

A)  Allopolyploidy involves disruptive selection. 
B)  Autopolyploidy involves disruptive selection. 
C)  If speciation is allopatric rather than sympatric, then the mode of speciation is allopolyploidy. 
D)  In autopolyploidy, one parental species makes up the polyploidy. 
E)  In allopolyploidy, two parental species make up the polyploidy. 
A)  Allopolyploidy involves disruptive selection. 
B)  Autopolyploidy involves disruptive selection. 
C)  If speciation is allopatric rather than sympatric, then the mode of speciation is allopolyploidy. 
D)  In autopolyploidy, one parental species makes up the polyploidy. 
E)  In allopolyploidy, two parental species make up the polyploidy.

Question 12

Rhagoletis pomonella in the Hudson River Valley of New York State

Accepted Answer

A)  is an example of a species in which allopatric speciation may be occurring. 
B)  has formed two subpopulations because of a geological barrier that separates them. 
C)  has formed two groups based on their preference for either apple or hawthorn fruits. 
D)  has formed new species by polyploidy. 
E)  has formed two groups with similar allele frequencies. 
A)  is an example of a species in which allopatric speciation may be occurring. 
B)  has formed two subpopulations because of a geological barrier that separates them. 
C)  has formed two groups based on their preference for either apple or hawthorn fruits. 
D)  has formed new species by polyploidy. 
E)  has formed two groups with similar allele frequencies.

Question 13

Drosophila species that have been crossed with each other allow evolutionary biologists to make general inferences about their evolution. The diagram below shows the relationship between prezygotic reproductive isolation and genetic distance for both allopatric and sympatric pairs. What is the likely explanation for the patterns observed?

Accepted Answer

Reinforcement is accelerating

Question 14

Which of the following statements about polyploidy in plants is correct?

Accepted Answer

A)  Polyploidy is rare in plants. 
B)  Allopolyploids are hybrid plants that result from the mating of two closely related species. 
C)  Tetraploid plants can mate with other tetraploid plants of the same species, but not with themselves. 
D)  Tetraploid and diploid plants of a given species can mate to produce viable triploid offspring. 
E)  Polyploid plants are usually less vigorous than diploid plants of the same species. 
A)  Polyploidy is rare in plants. 
B)  Allopolyploids are hybrid plants that result from the mating of two closely related species. 
C)  Tetraploid plants can mate with other tetraploid plants of the same species, but not with themselves. 
D)  Tetraploid and diploid plants of a given species can mate to produce viable triploid offspring. 
E)  Polyploid plants are usually less vigorous than diploid plants of the same species.

Question 15

Which of the following is believed to be the dominant mode of speciation among most groups of organisms?

Accepted Answer

A)  Allopatric speciation 
B)  Sympatric speciation 
C)  Reinforcement 
D)  Hybrid speciation 
E)  Temporal speciation 
A)  Allopatric speciation 
B)  Sympatric speciation 
C)  Reinforcement 
D)  Hybrid speciation 
E)  Temporal speciation

Question 16

Which of the following conditions would not favor rapid speciation?

Accepted Answer

A)  There being many species in a group 
B)  Specialized diets of certain insects 
C)  Sexual selection 
D)  Good dispersal ability 
E)  Reproductive isolation 
A)  There being many species in a group 
B)  Specialized diets of certain insects 
C)  Sexual selection 
D)  Good dispersal ability 
E)  Reproductive isolation

Question 17

Hybrid zones are likely to be narrow

Accepted Answer

A)  in species that move around considerably during their lifetimes. 
B)  when reinforcement is occurring. 
C)  when there is strong selection against the hybrids. 
D)  when the hybrids are as fit as the original species. 
E)  when Muller's ratchet is operating. 
A)  in species that move around considerably during their lifetimes. 
B)  when reinforcement is occurring. 
C)  when there is strong selection against the hybrids. 
D)  when the hybrids are as fit as the original species. 
E)  when Muller's ratchet is operating.

Question 18

When differences in the shapes of reproductive organs between the males of one species and the females of the other species lead to incompatibility, the species are said to be exhibiting _______ isolation.

Accepted Answer

The answer of When differences in the shapes of reproductive...

Question 19

Two populations that were once isolated come in contact. Which of the following statements about what might happen is false?

Accepted Answer

A)  If hybrids are unfit, reinforcement of prezygotic barriers would be disfavored. 
B)  If reproductive isolation is not complete, the two populations could interbreed. 
C)  Hybrids, if fit, could spread through both populations, resulting in gene flow between them. 
D)  If reproductive isolation had been established, the two populations could not interbreed. 
E)  Hybrid zones that last for a long time could develop. 
A)  If hybrids are unfit, reinforcement of prezygotic barriers would be disfavored. 
B)  If reproductive isolation is not complete, the two populations could interbreed. 
C)  Hybrids, if fit, could spread through both populations, resulting in gene flow between them. 
D)  If reproductive isolation had been established, the two populations could not interbreed. 
E)  Hybrid zones that last for a long time could develop.

Question 20

Which of the following statements about the evolution of reproductive isolation is false?

Accepted Answer

A)  Reproductive isolation evolves at about the same rate in nearly all groups of organisms. 
B)  Reproductive isolation can gradually evolve in the lab, even if the researchers do not directly select for it. 
C)  Reproductive isolation gradually increases with increasing genetic distance. 
D)  Reproductive isolation is not "all-or-nothing": intermediate levels of reproductive isolation can be found. 
E)  All of the above are true; none is false. 
A)  Reproductive isolation evolves at about the same rate in nearly all groups of organisms. 
B)  Reproductive isolation can gradually evolve in the lab, even if the researchers do not directly select for it. 
C)  Reproductive isolation gradually increases with increasing genetic distance. 
D)  Reproductive isolation is not "all-or-nothing": intermediate levels of reproductive isolation can be found. 
E)  All of the above are true; none is false.

Exam 23: Species and Their Formation

Speciation is an important component of evolution because it

Suppose the hybrids of two salamander species exhibit reduced adult viability. These species would thus have a _______ reproductive isolating barrier.

Which of the following is a major limitation of the morphological species concept?

Which type of speciation is most common among flowering plants?

Which of the following factors would not be expected to increase the rate of speciation in a group of organisms?

Which of the following adaptations is not found among any of the species of Darwin's finches?

More than 800 species of Drosophila occur in the Hawaiian Islands, representing 30 to 40 percent of all the species in this genus. The occurrence of so many Drosophila species in this island chain is

Which of the following statements about speciation is true?

A field contains two related species of flowering plants. Species A has a diploid chromosome number of 16, and species B has a diploid number of 18. If a third species arises as a result of hybridization between A and B, how many chromosomes will it have?

What is the critical distinction between allopolyploidy and autopolyploidy?

Rhagoletis pomonella in the Hudson River Valley of New York State

Which of the following statements about polyploidy in plants is correct?

Which of the following is believed to be the dominant mode of speciation among most groups of organisms?

Which of the following conditions would not favor rapid speciation?

Hybrid zones are likely to be narrow

When differences in the shapes of reproductive organs between the males of one species and the females of the other species lead to incompatibility, the species are said to be exhibiting _______ isolation.

Two populations that were once isolated come in contact. Which of the following statements about what might happen is false?

Which of the following statements about the evolution of reproductive isolation is false?

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 Signaling and Communication

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

Recombinent Dna and Biotechnology

Differential Gene Expression in Development

Development and Evolutionary Change

Evidence and Mechanisms of Evolution

Reconstructing and Using Phylogenies

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria and Archaea: the Prokaryotic Domains

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

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 and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Function

Musculoskeletal Systems

Gas Exchange in Animals

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen

Animal Behavior

Ecology and the Distribution of Life

Population Ecology

Species Interaction and Coevolution

Community Ecology

Ecosystems and Global Ecology

Conservation Biology

Filters