Download Genetic Change - Minneota Public Schools

Name ______________________________ Class___________________Date__________________
Skills Worksheet
Directed Reading
Section: Genetic Change
In the space provided, write the letter of the description that best matches each term.
_____ 1. genetic equilibrium
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a. the movement of alleles into and out of a
population
2. gene flow
b. one of the most powerful agents of genetic
change
3. nonrandom mating c. eliminates individuals with average phenotype
values
4. genetic drift
d. a change in allele frequency because of
random occurrences
5. mutation
e. the state of a population in which no genetic
change occurs
6. natural selection
f. the mechanism that drives evolution
7. stabilizing selection g. individuals show preferences in the choice of
breeding partners
8. disruptive selection h. eliminates individuals that have alleles for any
extreme type
In the space provided, explain how the terms in each pair are related to each other.
9. gene flow, genetic drift
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10. mutation, natural selection
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11. directional selection, stabilizing selection
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology
3
Population Genetics and Speciation
Name ______________________________ Class___________________Date__________________
Directed Reading continued
Read each question, and write your answer in the space provided.
12. What are the five forces of genetic change?
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13. What does the Hardy-Weinberg principle predict?
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14. Explain why natural selection does not act directly on genes.
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15. Explain how sexual reproduction affects evolution.
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16. What effect does nonrandom mating have on the frequency of alleles in a
population?
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17. Explain how natural selection is limited.
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18. Describe directional selection and give an example.
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19. Describe stabilizing selection.
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20. What is disruptive selection?
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Biology
4
Population Genetics and Speciation