chapter 20

evolution quiz

1. What do individuals represent in different combinations of?
A. Alleles drawn from the species' gene pool
B. Organs inherited from parents
C. Traits learned from the environment
D. Cells copied from ancestors

A

2. What are the two sources of genetic variation?
A. Natural selection and evolution
B. Adaptation and inheritance
C. Mutation and recombination
D. Migration and genetic drift

C

3. How does mutation cause genetic variation?
A. It eliminates harmful genes only
B. It stabilizes existing traits
C. It increases population size
D. It generates new variation

D

4. How does recombination cause genetic variation?
A. It causes mutations to reverse
B. It removes mutations entirely
C. It shuffles mutations to create new combinations
D. It prevents natural selection

C

5. What do somatic mutations affect?
A. Future generations
B. Germ-line cells exclusively
C. Only the cells descended from the one cell the mutation originally arose in
D. The entire organism and its descendants

C

6. What do germ-line mutations affect?
A. Only the individual’s behavior
B. Only body cells
C. Cannot be inherited
D. They’re passed on to the next generation

D

7. What are the types of mutations?
A. Dominant, recessive, and silent
B. Primary, secondary, and tertiary
C. Adaptive, generative, and harmful
D. Neutral, deleterious, and advantageous

D

8. What are the mutations that result in a species adapting better to an environment?
A. Deleterious mutations
B. Somatic mutations
C. Neutral mutations
D. Advantageous mutations

D

9. What’s the goal of population genetics?
A. To eliminate genetic disorders
B. To make inferences about the evolutionary process from patterns of genetic variation in nature
C. To compare plant and animal anatomy
D. To catalog all genes in humans

B

10. Example of genotype frequency?
A. 100% dominant alleles
B. 2:1 ratio of phenotypes
C. 50% aa, 25% Aa, 25% AA
D. 25% A, 75% a

C

11. Example of allele frequency?
A. 1:1 phenotypic ratio
B. 37.5% A and 62.5% a
C. 40% AA and 60% aa
D. 100% genotype

B

12. What are the 3 ways to measure genotype and allele frequencies in populations?
A. Observable traits, gel electrophoresis, and DNA sequencing
B. Carbon dating, fossils, and RNA splicing
C. Behavioral studies, DNA cloning, and protein folding
D. Morphology, taxonomy, and environmental sampling

A

13. What’s the gold standard for measuring genetic variation?
A. Gel electrophoresis
B. Observing traits
C. Blood typing
D. DNA sequencing

D

14. What does calculating allele frequencies with DNA sequencing involve?
A. Measuring gene expression levels
B. Collecting a population sample and counting the number of occurrences of a given mutation
C. Sequencing only dominant alleles
D. Cloning the entire genome

B

15. What is evolution a change in?
A. Allele or genotype frequency over time
B. Physical appearance only
C. Environmental conditions
D. Behavior over generations

A

16. What does the Hardy-Weinberg equilibrium describe?
A. Evolution occurring rapidly
B. Reproduction without variation
C. A balance between predator and prey
D. Situation where allele and genotype frequencies do not change

D

17. What happens in the absence of evolutionary forces?
A. Only dominant alleles survive
B. Allele and genotype frequencies do not change
C. New species arise
D. Species go extinct

B

18. What are the conditions for the Hardy-Weinberg equilibrium?
A. Frequent mutations and natural selection
B. No selection, large population size, no mutation, random mating, no migration
C. Asexual reproduction only
D. Nonrandom mating and small population

B

19. What does natural selection result in?
A. Individuals choosing their mutations
B. Allele frequencies change from generation to generation
C. Traits being copied exactly
D. The elimination of all variation

B

20. What does natural selection bring about?
A. Adaptations
B. Extinction
C. Mutations
D. Recombination

A

21. What are the observations that make up the theory of natural selection?
A. Variation, heritability, competition, survival of the fittest
B. All traits are inherited
C. Equal success in all organisms
D. Genetic drift, mutation, migration, recombination

A

22. How did Darwin use the term natural selection?
A. A way to eliminate random mating
B. The filtering process that acts against deleterious alleles and in favor of advantageous ones
C. A form of artificial breeding
D. A method for studying fossils

B

23. What does natural selection act over generations to do?
A. Prevent reproduction
B. Stop variation
C. Decrease mutations
D. Increase the overall fitness of a population

D

24. What does the modern synthesis combine?
A. Mendelian genetics and Darwinian evolution
B. DNA sequencing and taxonomy
C. Cloning and artificial selection
D. Population studies and mutation tracking

A

25. What does Darwinian evolution address?
A. The change over time of the genetic composition of populations
B. Fossil preservation
C. Inheritance of acquired traits
D. The evolution of individuals

A

26. What does natural selection increase and decrease the frequency of?
A. Decreases recombination
B. Increases all mutations
C. Increases advantageous, decreases deleterious mutations
D. Increases gene flow

C

27. What are most mutations to genes?
A. Neutral
B. Deleterious
C. Recessive
D. Advantageous

B

28. When is natural selection inefficient at eliminating a deleterious allele?
A. When it's dominant
B. When it's frequent
C. When it is recessive
D. When it’s visible

C

29. When will negative selection only act against an allele?
A. When it is present in a homozygote
B. When it's neutral
C. When it's dominant
D. When it's in the germ-line

A

30. What's a form of balancing selection?
A. Genetic drift
B. Bottleneck effect
C. Heterozygote advantage
D. Disruptive selection

C

31. How is the heterozygote advantage illustrated?
A. Human populations in Africa and malaria resistance
B. Finch beak size
C. Polar bear fur thickness
D. Butterfly coloration

A

32. What can natural selection be in terms of consequences?
A. Dominant or recessive
B. Stabilizing, directional, or disruptive
C. Long-term or short-term
D. Positive, neutral, or silent

B

33. What's an example of stabilizing selection?
A. Human birth weight
B. Finch beak depth
C. Mutation rate
D. Antibiotic resistance

A

34. What's an example of directional selection?
A. Average height staying the same
B. Finch's beak size increases after drought
C. Genetic drift
D. Human eye color

B

35. What does directional selection shift?
A. Gene flow
B. The mating preference
C. The mutation rate
D. The population mean

D

36. What are the most dramatic examples of directional selection caused by?
A. Human attempts to control nature
B. Climate change
C. Random mating
D. Natural disasters

A

37. What's an example of disruptive selection?
A. Polar bear fur
B. Apple maggot flies
C. Sickle cell trait
D. Bacterial resistance

B

38. When do selective pressures tend to be constant?
A. When populations migrate
B. During rapid mutation
C. In a stable environment
D. In small populations

C

39. What can natural selection only respond to?
A. Past environments
B. Current conditions
C. Future goals
D. Recessive alleles

B

40. What’s another form of directional selection?
A. Artificial selection
B. Balancing selection
C. Negative selection
D. Random mating

A

41. What's the key difference between natural and artificial selection?
A. Artificial only affects animals
B. Natural results in harmful traits
C. Natural is faster
D. Natural has no goal, artificial does

D

42. What does sexual selection promote in traits?
A. Traits that increase access to reproductive opportunities
B. Traits that avoid predators
C. Traits that increase survival only
D. Random mutations

A

43. What are the mechanisms of evolution?
A. Natural selection, mutation, and taxonomy
B. Adaptation, extinction, and growth
C. Genetic drift, migration, and nonrandom mating
D. Phenotype, recombination, and dominance

C

44. What is genetic drift?
A. A form of selection that favors new alleles
B. A process that increases mutation rate
C. A kind of sampling error that results in a change in allele frequency
D. A result of random mating

C

45. What is lost in genetic drift?
A. Genetic variation
B. Body traits
C. Gene flow
D. Mutation rate

A

46. Does natural selection govern the fate of neutral mutations?
A. Yes, always
B. Only when beneficial
C. Only in large populations
D. No

D

47. What are neutral mutations lost by, if not natural selection?
A. Migration
B. Mutation
C. Random change, i.e., genetic drift
D. Natural selection

C

48. How is genetic drift different from natural selection?
A. It increases fitness
B. It acts only on dominant alleles
C. It does not affect fitness
D. It only happens in large populations

C

49. Where does genetic drift have a large effect?
A. Stable environments
B. Small populations
C. High-fitness organisms
D. Mutated populations

B

50. What does migration reduce?
A. Overall diversity
B. Genetic variation between populations
C. Mutation rates
D. Reproductive success

B

51. What does migration involve?
A. Chromosome duplication
B. The movement of alleles between populations
C. Gene silencing
D. Only movement of individuals

B

52. What effect does migration tend to have on populations?
A. Disruptive effect
B. Homogenizing effect
C. Directional selection
D. Isolation

B

53. What is the ultimate source of variation?
A. Recombination
B. Selection
C. Mutation
D. Migration

C

54. What does mutation increase?
A. Reproductive rate
B. Genetic variation
C. Gene flow
D. Mating success

B

55. What does nonrandom mating alter?
A. Genotype frequencies without affecting allele frequencies
B. Allele frequencies only
C. Mutation rate
D. DNA sequence

A

56. How is nonrandom mating different from migration and mutation?
A. It eliminates variation
B. It does not introduce new alleles to the population
C. It increases mutation
D. It reduces recombination

B

57. What does nonrandom mating increase?
A. Genetic drift
B. Advantageous mutations
C. Homozygotes
D. Genetic diversity

C

58. What does nonrandom mating decrease?
A. Natural selection
B. Heterozygotes
C. Deleterious mutations
D. Population size

B

59. What does nonrandom mating not change?
A. Genotype frequencies
B. Fitness
C. Population structure
D. Allele frequencies

D

60. Where do mutations occur?
A. In every individual equally
B. Only during natural selection
C. In one population that have not arisen in the other population
D. In dominant alleles only

C

61. What are the three fates of a mutation in either population?
A. Inherited, hidden, duplicated
B. Beneficial, neutral, harmful
C. Fixation, maintained, eliminated
D. Dominant, recessive, lethal

C

62. How does a mutation go through fixation?
A. Negative selection
B. Genetic drift or positive selection
C. Random mating
D. Migration

B

63. How is a mutation maintained?
A. Through genetic drift
B. By balancing selection
C. Through elimination
D. By artificial selection

B

64. How does a mutation get eliminated?
A. Positive selection
B. Natural selection or genetic drift
C. Recombination
D. DNA replication errors

B

65. What is the extent of genetic difference between two species a function of?
A. Mutation rate
B. The time they’ve been genetically isolated
C. Gene dominance
D. Chromosome number

B

66. What does it mean that the longer the species have been apart?
A. The less likely they are to survive
B. More opportunities for mutation and fixation to occur
C. Their environments are more similar
D. They share more traits

B

67. What does the slowest molecular clock belong to?
A. Histone genes
B. Pseudogenes
C. Mitochondrial DNA
D. Y chromosomes

A

68. Why is the gene’s molecular clock slow?
A. It replicates less often
B. It has more introns
C. There’s a lot of negative selection
D. It only exists in somatic cells

C

69. What does the fastest molecular clock belong to?
A. Repetitive DNA
B. Histone genes
C. Mitochondrial genes
D. Pseudogenes

D

70. Why are pseudogenes a fast molecular clock?
A. They are actively transcribed
B. They resist mutations
C. All mutations in a pseudogene are neutral, so there is no selection against them
D. They replicate faster than other genes

C

71. Why do the rate of molecular clocks vary among genes?
A. Some genes have fewer exons
B. Some genes are subject to more intense negative selection than others
C. Genes differ by length
D. Some genes are only found in animals

B