Deck 7: Evolution and Adaptation

Question 1

Consider three populations of a plant species, each isolated from other populations of the same species. Population X has contained approximately 100 individuals in each generation for the past 200 generations. Population Y has contained approximately 10 000 individuals in each generation for the past 200 generations. Population Z has contained approximately 1 million individuals in each generation for the past 200 generations. If genetic drift is the only evolutionary process acting on these populations, how can we expect the amount of genetic variation to differ among these populations?

A) X will have the highest variation, Y will have intermediate variation, and Z will have the lowest variation.
B) X will have the lowest variation, Y will have intermediate variation, and Z will have the highest variation.
C) X and Z will have high variation, while Z will have low variation.
D) All three populations will have the same amount of genetic variation.

Answer 1

B

Question 2

Which of the following types of allele would we expect to have the lowest frequency in a population?

A) beneficial recessive allele
B) beneficial dominant allele
C) harmful recessive allele
D) harmful dominant allele

Answer 2

D

Question 3

What term refers to the alleles of all of the genes of every individual in a population?

A) polygenic
B) heterozygous
C) gene pool
D) random assortment

Answer 3

C

Question 4

Different forms of a particular gene are known as

A) chromosomes.
B) alleles.
C) polygenic.
D) pleiotropic.

Question 5

Consider a situation in which overharvesting causes the number of fish in a population to become drastically smaller, which causes genetic variation in that fish to decrease over a few generations. This is an example of

A) bottleneck effect.
B) founder effect.
C) directional selection.
D) recombination.

Question 6

Many genetic diseases have severe or lethal effects in the homozygous form, yet alleles for these diseases are not entirely removed by natural selection. Explain how dominance relationships among alleles allow deleterious mutations to remain in a population.

Question 7

The shuffling of genes that occurs when DNA is copied during meiosis is known as

A) recombination.
B) mutation.
C) random assortment.
D) epistasis.

Question 8

Describe the difference between synonymous and nonsynonymous mutation. Which type is more likely to be affected by natural selection, and why?

Question 9

For mutations that enter a population of a diploid organism, which type of mutation is most likely to be affected by natural selection when it first appears?

A) synonymous mutation
B) nonsynonymous recessive mutation
C) nonsynonymous dominant mutation
D) All are equally likely to be affected by natural selection.

Question 10

The rate at which allele frequencies change because of genetic drift is

A) highest in large populations.
B) the same regardless of population size.
C) highest in intermediate-sized populations.
D) highest in small populations.

Question 11

Chickens with the dominant allele at the frizzle gene produce curly feathers, have very high body temperature, and lay few eggs. This is an example of

A) polygenic traits.
B) pleiotropy.
C) epistasis.
D) random assortment.

Question 12

Two of the genes that affect coat colour in horses are the extension gene and the cream dilution gene. The dominant E allele at the extension gene generates black coats, while the recessive e allele produces red coats. The coat colour caused by the extension gene is not altered if the horse is a homozygote for the C allele at the cream dilution gene. However, if the horse is a homozygote for the C^Cr allele at the cream dilution gene, it will have a white coat regardless of the extension genotype. This interaction between the extension and the cream dilution gene is an example of

A) pleiotropy.
B) epistasis.
C) codominance.
D) random assortment.

Question 13

What process creates new alleles in a population?

A) random assortment
B) mutation
C) recombination
D) epistasis

Question 14

What term describes making new combinations of alleles using existing genetic variation across many chromosomes?

A) pleiotropy
B) epistasis
C) random assortment
D) mutation

Question 15

Which is (are) correct about founder effect?
I) Founder effect occurs when individuals are transplanted to a new location.
II) Founder effect produces new alleles.
III) Founder effect reduces genetic variation.

A) I only
B) II only
C) III only
D) I and II
E) I and III

Question 16

Consider a gene that affects fur colour in mice. This gene has two alleles, A and
A) A is dominant and a is recessive.

A) If AA mice have white fur, Aa mice have grey fur, and aa mice have black fur, how would we describe the effect of these alleles?
B) A is recessive and a is dominant.
C) A and a are codominant.
D) A and a are epistatic.

Question 17

Consider a gene that affects number of seeds in a plant. This gene has two alleles, G and

A) G is dominant and g is recessive.
B) G is recessive and g is dominant.
C) G and g are codominant.
D) G and g are polygenic.
G) If GG plants produce 50 seeds, Gg plants produce 50 seeds, and gg plants produce 25 seeds, how would we describe the effect of these alleles?

Question 18

A trait that is determined by multiple genes is referred to as

A) polygenic.
B) pleiotropic.
C) homozygous.
D) heterozygous.

Question 19

A process that occurs when genetic variation is lost because of random variation in mating, mortality, fecundity, and inheritance is known as

A) mutation.
B) genetic drift.
C) stabilizing selection.
D) disruptive selection.

Question 20

Clonal animals do not reshuffle their genes through genetic recombination, whereas sexually reproducing animals do. Explain how this difference could affect how pathogens interact with clonal animals and how they interact with sexually reproducing animals.

Question 21

A small species of fly lays its eggs in plant stems. The developing fly larvae cause a gall, or large round structure, to form in the stem. Genetic differences among flies cause variation in the size of the galls they produce. Both birds and wasps feed on the larvae in the galls. The proportions of small, medium, and large galls able to survive attacks by either birds or wasps are shown in the table. If a population of flies lives in a field with equal abundance of birds and wasps, will gall size be by directional, stabilizing, or disruptive selection? Explain your answer.

Question 22

The phenomenon by which moths in England evolved from light-coloured forms to dark-coloured forms over several decades is known as

A) speciation.
B) epistasis.
C) genetic drift.
D) industrial melanism.

Question 23

The four plots in the figure show possible relationships between the survival and beak length in an island population of birds. Which plot is an example of disruptive selection?

A) plot a
B) plot b
C) plot c
D) plot d

Question 24

The evolution of pesticide resistance in insects is an example of

A) microevolution.
B) industrial melanism.
C) selective predation.
D) macroevolution.

Question 25

Which is a prediction of the hypothesis that predation caused industrial melanism?

A) Dark moths seek out dark trees to rest on.
B) Birds more frequently capture dark moths on dark trees than those on light trees.
C) Birds more frequently capture dark moths on light trees than those on dark trees.
D) Industrial pollution led to higher mortality of light moths.

Question 26

The drastic phenotypic differences between large dogs, such as Bloodhounds, and small dogs, such as Chihuahuas, are a result of

A) genetic drift.
B) founder effect.
C) artificial selection.
D) natural selection.

Question 27

Microevolution includes

A) speciation.
B) key innovation.
C) genetic drift.
D) polyploidy.

Question 28

Body size is a heritable trait in the amphipod, an aquatic crustacean. Fish preferentially consume large amphipods, leaving primarily small amphipods to breed. Based on these observations, how would we expect evolution to affect ponds with and without fish?

A) Ponds with fish should have larger amphipods.
B) Ponds with fish should have smaller amphipods.
C) Amphipod body size should not differ between ponds with and without fish.
D) Ponds with fish should have amphipods that are either very large or very small.

Question 29

The human activity of controlling the survival and reproduction of organisms to produce offspring with specific sets of traits is known as

A) artificial selection.
B) natural selection.
C) industrial melanism.
D) speciation.

Question 30

When a phenotype is under disruptive selection, which parts of the phenotypic distribution are expected to have the highest fitness?

A) individuals with the extreme largest values of the phenotype
B) individuals with the extreme smallest values of the phenotype
C) individuals with both extreme large and extreme small values of the phenotype
D) individuals with the intermediate phenotype

Question 31

When an extreme phenotype has higher fitness than an average phenotype in a population, it is an example of

A) stabilizing selection.
B) directional selection.
C) disruptive selection.
D) genetic drift.

Question 32

Consider three populations of a plant species, each of which is isolated from other populations of the same species. Population X has had approximately 100 individuals in each generation for the past 200 generations. Population Y has had approximately 10 000 individuals in each generation for the past 200 generations. Population Z has had approximately 1 million individuals in each generation for the past 200 generations. If the environment changed and a new environmental condition exerted the exact same strength of directional selection on all three populations, which population would we expect to evolve most rapidly?

A) population X
B) population Y
C) population Z
D) All three populations would evolve at the same rate.

Question 33

You conduct an experiment in which you raise six replicated lines of fruit flies for eight generations. You keep population size constant at 20 adults per generation. You are interested in a gene, bw, that affects eye colour. This gene has two alleles, bw-1 and bw-2. You start each replicated line with the frequency of the bw-1 allele at 50%. Do the data in the graph better match the prediction for the bw alleles evolving by genetic drift or by directional selection? Be sure to define directional selection and genetic drift and describe the prediction of both hypotheses.

Question 34

Which of the following statements about evolution by artificial selection is correct?

A) It occurs very slowly.
B) It was discovered only in the 1900s.
C) It can have negative effects on humans.
D) It does not require genetic variation.

Question 35

If a population of butterflies is under strong natural selection favouring large wings but there is no genetic variation for wing size, what do we expect to occur in the next generation?

A) Wings will evolve to be smaller.
B) There will be no evolutionary change in wing size.
C) Wings will evolve to be larger.
D) Wings will evolve to be more variable.

Question 36

Which of the following insights about microevolution is demonstrated by industrial melanism?

A) Artificial selection cannot be reversed.
B) Microevolution is primarily caused by genetic drift.
C) Humans affect the evolution only of domestic animals.
D) Microevolution can occur in a very short time.

Question 37

A group of island birds have beaks that are on average 20 mm long with a standard deviation of 1 mm. Beak length is a genetically based trait with a heritability of 0.5. Only small seeds are available for these birds to consume, and some of the large-beaked birds are unable to reproduce. The group of birds that successfully reproduces has an average beak size of 16 mm. Based on this information, predict how much the beak size is expected to change in the next generation.

Question 38

Stickleback fish exhibit variation in a morphological trait known as gill rakers. Fish with long gill rakers are very good at eating plankton, and fish with short gill rakers are good at eating deep-water invertebrates. However, fish with intermediate-length gill rakers are poor at eating either type of food. Fish that are better at consuming food have higher survival and reproduction rates than poorer consumers. Based on this information, what type of selection is likely acting on stickleback gill raker length?

A) no natural selection
B) stabilizing selection
C) disruptive selection
D) directional selection

Question 39

When a parental generation undergoes stabilizing selection, how will the distribution of phenotypes in the population change between the parental generation and their progeny?

A) Mean phenotype increases, but variability decreases.
B) Mean phenotype stays the same, but variability decreases.
C) Mean phenotype stays the same, but variability increases.
D) Mean phenotype and variability both increase.

Question 40

Evolution by artificial selection is similar to evolution by natural selection because
I) both require traits to be heritable.
II) both incorporate founder effects.
III) both generate differences in fitness between individuals.

A) I only
B) II only
C) III only
D) I and III only
E) I, II, and III

Question 41

When an error in meiosis causes sexually reproducing species to generate zygotes with three or more sets of chromosomes, this is known as

A) pleiotropy.
B) epistasis.
C) polyploidy.
D) genetic drift.

Question 42

Which of the following is (are) correct?
I) Allopatric speciation can occur without geographic barriers.
II) Allopatric speciation is the most common form of speciation.
III) Allopatric speciation can be facilitated through genetic drift.

A) I only
B) II only
C) III only
D) I and III
E) II and III

Question 43

Why is polyploid speciation useful to humans?

Question 44

Darwin supported his argument for evolution by natural selection with the observation that artificial selection caused large changes in a short period because

A) natural selection had millions of years to operate.
B) genetic drift could not cause the same rate of change.
C) natural selection had to have occurred in only a few generations.
D) allopatric speciation requires geographic barriers.

Question 45

Use the following figure to answer questions 46 and 47.

Based on the phylogeny in the figure, which group is most closely related to the reptiles?

A) lampreys
B) lungfishes
C) amphibians
D) mammals

Question 46

Which of the following three statements is (are) correct?
I) Speciation through polyploidy can occur through hybridization.
II) Speciation through polyploidy never occurs in vertebrates; it occurs only in plants.
III) Speciation through polyploidy generates phenotypic differences among the resulting species.

A) I only
B) II only
C) III only
D) I and II
E) I and III

Question 47

Which of the following is (are) correct?
I) Sympatric speciation occurs without geographic barriers.
II) Sympatric speciation can occur through polyploidy.
III) Sympatric speciation is less common than allopatric speciation.

A) I only
B) II only
C) III only
D) I and III
E) I, II, and III

Question 48

The drug chloroquine has been widely used to treat the human parasite malaria. Mutations in the malaria gene pfcrt confer resistance to chloroquine. In some countries, more than 90% of malaria parasites had the pfcrt resistance alleles. When these countries stopped using chloroquine, the frequency of the pfcrt resistance alleles rapidly declined. Provide an evolutionary explanation for the decline in pfcrt resistance alleles after chloroquine was discontinued.

Question 49

Describe how genetic drift and natural selection can play a role in allopatric speciation.

Question 50

What is the term for evolution that acts at the level of species, genera, and higher levels of organization?

A) microevolution
B) macroevolution
C) genetic drift
D) epistasis

Question 51

How might understanding microevolution have a direct benefit to humans in the fight against diseases?

Question 52

Artificial selection can cause evolutionary change when there is

A) genetic variation in traits.
B) geographic separation.
C) a founder effect.
D) key innovation.

Question 53

An evolutionary novel trait that allows a species to use new niches and undergo a high rate of speciation is

A) a key innovation.
B) a polyploid species.
C) pleiotropy.
D) a phylogenetic tree.

Question 54

Explain how a diversity of habitats combined with natural selection can lead to sympatric speciation. Provide an example.

Question 55

Use the following figure to answer questions 46 and 47.

Based on the phylogeny in the figure, which traits are shared by bony fishes and amphibians?

A) jaws and lungs
B) bony skeleton and lungs
C) jaws and bony skeleton
D) legs and lungs

Question 56

Which of the following is a necessary component of allopatric speciation?

A) hybridization
B) polyploidy
C) a geographic barrier
D) key innovations

Question 57

Which of the following is a component of macroevolution?

A) artificial selection
B) epistasis
C) founder effect
D) sympatric speciation

Question 58

Angiosperms, the flowering plants, are much more diverse than other groups of plants. One reason for this is the evolution of flowers, which increased plant interactions with pollinators and drastically increased speciation rates. This is an example of

A) microevolution.
B) key innovation.
C) pleiotropy.
D) disruptive selection.

Question 59

If climate change were to cause a tree with very dark bark to become common in England, what would we expect to happen to the colour patterns of the peppered moth¸ and why would we expect it to happen?

Question 60

Based on the phylogeny of the Galapagos finches, which statement is correct?

A) Eating insects is a key innovation.
B) The ancestor of the small tree finch and large tree finch probably ate insects.
C) The ancestor of the large cactus finch and common cactus finch likely ate insects.
D) The small tree finch is most closely related to the sharp-beaked finch.