1. Most Traits are Not Controlled by Simple __________________________
2. When several genes influence a trait, the trait is ______________________
3. Give two examples of polygenic traits: _______________________________
4. Give an example of incomplete dominance: ____________________________
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5. Give an example of codominance: ___________________________________
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6. Explain the difference between incomplete dominance & codominance.
______________________________________________________________
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7. What is a multiple allele: _________________________________________
Give an example: ______________________________________________
8. What are the four blood types possible in humans: _____________________
9. How does the color of hydrangea depend on the environment?
______________________________________________________________
______________________________________________________________
10. How does the fur color of Siamese cats depend on the environment?
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11. What human trait is influenced by environment? _______________________
12. Some Traits Are Caused by _______________________
13. Why are most bald people men? ___________________________________
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14. What is a mutation? ___________________________________________
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15. Sketch the shape of blood cells
of people that have sickle cell anemia
and normal blood cells.

16. Why does the shape of the blood cell cause problems?
______________________________________________________________
17. What advantage do people with the heterozygous condition for sickle cell anemia have? ___________________________________________________
18. What is hemophilia? ___________________________________________
19. What are the symptoms of Huntington's disease?
______________________________________________________________
20. What is genetic counseling? _____________________________________
___________________________________________________________
21. What would happen to a baby if PKU was not diagnosed early?
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22. What is gene therapy?
_____________________________________________________________
23. What are the symptoms of cystic fibrosis? (see table 8-2)
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24. What are the symptoms of Tay-Sachs disease (see table 8-2)
______________________________________________________________
25. See Health Watch: Genetic Counseling
What kind of people may want to see a genetic counselor?
_____________________________________________________________
What procedures do genetic counselors perform?
_____________________________________________________________
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