ap lectureguide14

AP Biology: CHAPTER 14

 MENDEL AND THE GENE IDEA

1. How does the “blending hypothesis” differ from the “particulate hypothesis” for the

transmission of traits?

__________________________________________________________________________

__________________________________________________________________________

2. List a few of the advantages of Mendel’s choice of the garden pea as a model organism.

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

3. Use the diagram to label the generations: P, F1, F2, pure, hybrid, and make notes of Mendel’s observations.

5. Using the diagram in Question 3, describe how the Law of Segregation applies to the F1 and to the F2 generations.

__________________________________________________________________________

__________________________________________________________________________

6. When does the segregation of alleles occur? _____________________________________

7. What is the difference between an allele and a gene?

a. allele __________________________________________________________________

__________________________________________________________________________

b. gene __________________________________________________________________

__________________________________________________________________________

8. Briefly define the following terms:

a. homozygous ____________________________________________________________

b. heterozygous ___________________________________________________________

c. phenotype ______________________________________________________________

d. genotype _______________________________________________________________

9. What is the purpose of a test cross? ____________________________________________

__________________________________________________________________________

__________________________________________________________________________

10. When two traits are on different (non-homologous) chromosomes, how are they inherited?

__________________________________________________________________________

__________________________________________________________________________

a. Indicate the phenotypic ratios that result in the F2 from the F1 cross (dihybrid cross)

11. Use the rules of probability to determine the expected ratio of offspring showing two recessive traits in the trihybrid cross (PpYyRr X Ppyyrr).

 

12. Describe and give an example of incomplete dominance. ___________________________

__________________________________________________________________________

__________________________________________________________________________

13. How does codominance compare to incomplete dominance? ________________________

__________________________________________________________________________

__________________________________________________________________________

14. How is blood type an example of multiple alleles? _________________________________

__________________________________________________________________________

__________________________________________________________________________

15. Define and give an example of pleiotropy. _______________________________________

__________________________________________________________________________

16. Define and give an example of epistasis. ________________________________________

__________________________________________________________________________

17. What is observed when traits are polygenic? _____________________________________

__________________________________________________________________________

18. The expression of phenotypes is often a result of both… ____________________________

__________________________________________________________________________

19. Briefly describe each of the following genetic disorders:

a. Cystic fibrosis ___________________________________________________________

__________________________________________________________________________

b. Tay-Sachs _____________________________________________________________

__________________________________________________________________________

c. Sickle cell anemia _______________________________________________________

__________________________________________________________________________

d. Achondroplasia __________________________________________________________

__________________________________________________________________________

e. Huntington’s disease _____________________________________________________

__________________________________________________________________________

20. How can a parent learn the risks of having a child with a genetic disorder?

__________________________________________________________________________