Chapter 11 The Process of Evolution Test Questions & Answers - Biology of Plants 8e Answer Key + Test Bank by Ray F. Evert. DOCX document preview.
Chapter 11: The Process of Evolution
Multiple-Choice Questions
______ warned of the hazards of increased human population growth.
a. Charles Lyell
b. Gregor Mendel
c. Thomas Malthus
d. Charles Darwin
e. Jean Baptiste de Lamarck
Humans breed plants and animals through the process of:
a. artificial selection.
b. natural selection.
c. survival of the fittest.
d. evolution.
e. mutation.
______ is the sum total of all the alleles of all the genes in a population.
a. The genotype
b. The gene pool
c. Evolution
d. Population genetics
e. A species
When biologists speak of the “fitness” of an organism they are referring to:
a. its strength.
b. its beauty.
c. its resistance to disease.
d. the size of its gene pool.
e. the number of its surviving offspring.
5. The Behavior of Genes in Populations: The Hardy-Weinberg Law; p. 212; difficult;
Which of the following statements concerning the Hardy-Weinberg Law is FALSE?
a. It explains why dominant alleles do not drive out recessives.
b. It explains why dominant and recessive alleles can remain in a population.
c. It provides a standard for detecting evolutionary change.
d. It provides a standard against which we can measure changes in allele frequencies.
e. It involves conditions that are usually met in natural populations.
Which of the following is NOT a necessary condition for a population to be in Hardy-Weinberg equilibrium?
a. no natural selection
b. isolation from other populations
c. no mutations
d. nonrandom mating
e. large population size
Which is the mathematical representation of the Hardy-Weinberg equilibrium?
a. p2 + q2 = 0
b. p2+ 2pq + q2 = 1
c. p2+ q2 = 1
d. 2pq + (p2 + q2) = 1
e. 2pq + 2(pq2) = p2 + q2 = 1
In a population that is in Hardy-Weinberg equilibrium, the frequency of a particular recessive allele is 40 percent. What proportion of the population is homozygous for the dominant allele?
a. 60 percent
b. 40 percent
c. 36 percent
d. 16 percent
e. 6 percent
In a population that is in Hardy-Weinberg equilibrium, the frequency of a particular dominant allele is 20 percent. What percentage of the individuals in this population will be heterozygous for that trait?
a. 16 percent
b. 32 percent
c. 42 percent
d. 64 percent
e. 80 percent
In a population that is in Hardy-Weinberg equilibrium, the frequency of a particular dominant allele is 70 percent, and the frequency of the recessive allele is 30 percent. In the next generation, the frequency of the dominant allele will be ______ percent and the frequency of the recessive allele will be ______ percent.
a. 70; 30
b. 60; 40
c. 50; 50
d. 40: 60
e. 30; 70
The raw material for evolutionary change is provided by:
a. sexual reproduction.
b. asexual reproduction.
c. mutations.
d. meiosis.
e. mitosis.
In a population, ______ results from the immigration or emigration of individuals.
a. mutation
b. genetic drift
c. gene flow
d. natural selection
e. nonrandom mating
In a population of 1000 plants, the frequency of the a allele is 5 percent. Suppose a fire causes the loss of 500 individuals who are homozygous for the A allele. In this case the fire caused the frequency of a to change from ______ to ______.
a. 5; 1
b. 0.05; 1.0
c. 0.05; 0.1
d. 0.5; 1.0
e. 0.5; 0.1
By definition, _______ is the term that refers to changes in a gene pool due to chance.
a. mutation
b. genetic drift
c. gene flow
d. natural selection
e. nonrandom mating
An example of ______ is when a single plant seed is carried by the wind to a remote island where it initiates a new population.
a. nonrandom mating
b. natural selection
c. fitness
d. the founder effect
e. the bottleneck effect
An example of ______ is when a forest fire destroys a large percentage of a population of trees.
a. nonrandom mating
b. natural selection
c. fitness
d. the founder effect
e. the bottleneck effect
When plants heterozygous for a trait self-pollinate there will be a(n):
a. decrease in the frequency of individuals homozygous recessive for that trait.
b. decrease in the frequency of individuals homozygous dominant for that trait.
c. decrease in the frequency of individuals heterozygous for that trait.
d. increase in the frequency of individuals heterozygous for that trait.
e. increase in the frequency of homozygous recessive individuals but a decrease in homozygous dominant individuals.
In a population, natural selection:
a. can preserve and promote variability.
b. eliminates only the “less fit.”
c. acts on the genotype.
d. reduces genetic variability.
e. reduces the potential for further evolution.
As an example of rapid evolutionary change, one variety of Agrostis grows much faster on tailings and dumps around abandoned lead mines than does another variety. What is the explanation for this?
a. The high lead content of the soil causes an increase in the mutation rate.
b. Lead stimulates the growth of plants.
c. Selection has favored the development of the lead-resistant variety.
d. Selection has favored the development of the lead-sensitive variety.
e. Lead stimulates the production of poisons that protect the plants against predators.
Which of the following statements about adaptation is FALSE?
a. It means a state of being adjusted to the environment.
b. It means a particular characteristic that aids in the adjustment of an organism to its environment.
c. It means an evolutionary process that produces organisms better suited to their environment.
d. It is correlated with selective forces exerted by the environment but not by other organisms.
e. It may occur over the course of many generations.
The tendency of individuals to vary over time in response to different environmental conditions is called:
a. adaptation.
b. developmental plasticity.
c. heterozygote advantage.
d. genotypic plasticity.
e. hybrid vigor.
Which of the following statements concerning ecotypes is FALSE?
a. They are members of a species occupying different habitats.
b. They exhibit a gradual change in phenotype correlated with gradual changes in the environment.
c. They usually differ physiologically.
d. They usually differ morphologically.
e. They usually differ genetically.
The experiments with Potentilla glandulosa showed that this organism:
a. grows well only at high altitudes.
b. grows well only at sea level.
c. should be regarded as four different species.
d. exists as four distinct ecotypes.
e. exists as two ecotypes, each with the same physiological response to the environment.
The experiments with Oxyria digyna and Solidago virgaurea provide evidence that:
a. natural selection does not always result in adaptation.
b. these species lack developmental plasticity.
c. clines can sometimes be ignored.
d. coevolution had occurred.
e. ecotypes differ physiologically.
______ refers to the adjustments that occur when populations of different species exert a strong selective force on each other.
a. Genetic drift
b. Developmental plasticity
c. Heterozygote advantage
d. Coevolution
e. Speciation
The key criterion of the biological species concept is that the members of a species:
a. have a similar anatomy.
b. have a similar morphology.
c. are all genetically isolated from other species.
d. can hybridize with each other.
e. can live in the same area.
If two groups are genetically isolated from each other, then by definition:
a. the two groups look different.
b. one group cannot exchange genes with the other group.
c. one group lives longer than the other.
d. one group is more fit than the other group.
e. gene flow occurs between the two groups.
The existence of Platanus × hybrida is indicative of the fact that:
a. fertile hybrids between species can occur.
b. members of different species do not ordinarily interbreed in nature.
c. members of different species should really be considered part of the same species.
d. morphologically distinct species should be considered subspecies.
e. the London plane tree should be considered a separate species in its own right.
One approach of the phylogenetic species concept states that species are defined on the basis of their:
a. ability to interbreed.
b. inability to interbreed.
c. ability to form fertile hybrids.
d. ability to form ecotypes with other species.
e. historical relatedness to other organisms in the species.
Allopatric speciation is different from sympatric speciation in that allopatric speciation involves:
a. polyploidy.
b. geographic isolation.
c. hybridization.
d. nondisjunction during meiosis.
e. nondisjunction during mitosis.
Which of the following statements about allopatric speciation is FALSE?
a. Flowering plants tend to speciate over small distances.
b. Snails tend to speciate over small distances.
c. Birds tend to speciate over large distances.
d. Organisms with restricted dispersal should form new species over large areas.
e. Organisms with large dispersal ability should form species over large distances.
Which of the following statements about sympatric speciation is FALSE?
a. It is more common than allopatric speciation.
b. It involves a doubling of chromosome number.
c. It involves the formation of polyploids.
d. It can arise as a result of nondisjunction.
e. It involves speciation without geographic separation.
The type of polyploidy known as allopolyploidy:
a. was discovered in Oenothera lamarckiana by Hugo de Vries.
b. involves a doubling of chromosome number within individuals of a species.
c. is involved in allopatric speciation.
d. is involved in adaptive radiation.
e. is more common than autopolyploidy.
Approximately ______ percent of flowering plants are polyploid.
a. 10 to 25
b. 35 to 47
c. 47 to 70
d. 70 to 83
e. 83 to 95
Tragopogon mirus and Tragopogon miscellus are examples of species formed by:
a. allopatric speciation.
b. heterozygote advantage.
c. coevolution.
d. allopolyploid speciation.
e. autopolyploid speciation.
One of the most important polyploid groups is the:
a. salt-marsh grasses.
b. wheats.
c. goat’s beards.
d. sunflowers.
e. horsetails.
An example of recombination speciation is provided by:
a. Triticum aestivum.
b. Spartina maritima.
c. Poa pratensis.
d. Tagopogon porrifolius.
e. Helianthus anomalus.
Which of the following statements concerning recombination speciation in sunflowers is FALSE?
a. It involves polyploidy.
b. It is a type of sympatric speciation.
c. The hybrids are initially semisterile.
d. It results from gene combinations being rearranged over several generations.
e. It has been duplicated in the laboratory.
Varieties of Kentucky bluegrass undergo a form of asexual reproduction known as ______ in which embryos that are genetically identical to the parent are produced.
a. hybridization
b. adaptive radiation
c. cross-pollination
d. apomixis
e. outcrossing
Apomixis is a type of:
a. sexual reproduction.
b. asexual reproduction.
c. hybridization.
d. outcrossing.
e. clinal variation.
Cross-pollination between individuals of the same species is called:
a. polyploidization.
b. hybridization.
c. recombination speciation.
d. outcrossing.
e. apomixis.
The origin of taxonomic groups above the level of the species is called:
a. coevolution.
b. punctuated equilibrium.
c. gradualism.
d. microevolution.
e. macroevolution.
According to the gradualism model:
a. the fossil record accurately reflects evolutionary history.
b. the origin of genera requires mechanisms different from those involved in the origin of species.
c. evolution occurs by the accumulation of many small changes in the frequencies of genes in a gene pool.
d. species arise abruptly.
e. new fossil forms appear rather suddenly in strata.
According to the theory of punctuated equilibrium:
a. macroevolution occurs more readily than microevolution.
b. species evolve by the gradual accumulation of many small changes.
c. the fossil record is flawed.
d. long periods of little phyletic change are interrupted by short periods of rapid change.
e. new species do not “suddenly” appear.
True-False Questions
An example of natural selection is a plant breeder developing a new variety of rose.
In the context of population genetics, fitness refers to an individual being physically fit to survive in a particular environment.
According to the Hardy-Weinberg Law, over long periods a dominant allele will drive out a recessive allele from a population.
The small-scale generation-to-generation change in the frequency of alleles in a population is called microevolution.
The rate of spontaneous mutations in a population is very low.
Gene flow can introduce new alleles into a population.
Genetic drift tends to have a greater impact on evolution in large populations than in small populations.
An example of the founder effect is a volcanic eruption destroying a large proportion of a particular plant population.
A trait that is favored in one environment may be disadvantageous in another.
Each group of distinct phenotypes that occupy different habitats is called a cline.
If two different populations of a species are genetically distinct they are called ecotypes.
Coevolution occurs when one species exerts a strong selective force on another.
The morphological species concept states that species are designated based on anatomical and morphological criteria.
In nature, allopatric speciation is more common than sympatric speciation.
In sympatric speciation, new species are formed by being separated geographically.
Polyploidy may arise as a result of nondisjunction during meiosis but not mitosis.
An example of adaptive radiation is the sudden diversification of new species from a common ancestor living on one of several neighboring islands.
Sympatric speciation can occur without polyploidy.
Apomixis is a type of asexual reproduction in which embryos are produced independent of fertilization.
The origin of taxonomic groups above the species level requires mechanisms that are different from those responsible for the origin of species.
The gradualism model of evolution states that a species appears abruptly in the fossil record.
Eldridge and Gould hypothesize that the punctuated equilibrium model of evolution can be explained in terms of allopatric speciation.
Essay Questions
1. Darwin’s Theory; p. 211; moderate
How would Darwin explain the observation that the size of a population of elephants remains relatively stable over time?
2. Darwin’s Theory; p. 211; moderate
Compare and contrast artificial and natural selection.
3. The Concept of the Gene Pool; pp. 211-212; easy
What does a population geneticist mean by the “fitness” of an individual in a population?
4. The Behavior of Genes in Populations: The Hardy-Weinberg Law; p. 212; moderate
If the five conditions specified for a gene pool in Hardy-Weinberg equilibrium are seldom met in natural populations, how do you explain the usefulness of the Hardy-Weinberg Law?
5. The Agents of Change; pp. 213-214; moderate
Explain the concept of genetic drift. In what ways are the bottleneck effect and the founder effect examples of genetic drift?
6. Responses to Selection; p. 215; moderate
Give an example of how the relative fitness of a trait depends on the environment.
7. The Result of Natural Selection: Adaptation; pp. 218-219; difficult
Describe how clines and ecotypes are reflections of developmental plasticity.
8. The Result of Natural Selection: Adaptation; p. 219; difficult
What accounts for the differences among Scandinavian ecotypes of goldenrod?
9. The Result of Natural Selection: Adaptation; p. 219; easy
Explain what is meant by coevolution, and give an example.
10. The Origin of Species; p. 220; moderate
Use the case of the two species of sycamores (Platanus) to discuss the problems associated with the biological species concept.
11. How Does Speciation Occur?; p. 221; moderate
Use examples to explain the difference between allopatric and sympatric speciation.
12. How Does Speciation Occur?; pp. 221-222; moderate
Explain the mechanisms by which autopolyploidy and allopolyploidy take place.
13. How Does Speciation Occur?; p. 227; moderate
Explain the concept of recombination speciation, and give an example.
14. The Origin of Major Groups of Organisms; pp. 229–230; moderate
Compare and contrast the gradualism and punctuated equilibrium models for the origin of major groups of organisms.