1. 11.2
Assessment Answers

2. What are the complex inheritance patterns discussed in section 11.2?
Incomplete dominance (flowers)
Codominance (checkered chicken, sickle cell)
Multiple Alleles (blood types, rabbit coat color)
Epistasis (labrador coat color)
Sex Linked ( hemophilia, red green color blindness)
Polygenic traits (skin color, height, eye color, fingerprints)

3. 2. Complex inheritance of traits does NOT follow inheritance patterns described by Mendel.

4. 3. How many phenotypes result in complete dominance
3. How many phenotypes result in complete dominance? Only two How many are homozygous? two How many are heterozygous? one

5. 4. In incomplete dominance, what is the word used to describe the heterozygous state? intermediate

6. 5. In codominance, how many alleles are expressed in the heterozygous state? both

7. 6. For the chicken example, the heterozygous state is BW
6. For the chicken example, the heterozygous state is BW. What would it be for the black chicken or white chicken? Black = BB, White = WW

8. 7. Sickle Cell Anemia is an example of a codominant inheritance
7. Sickle Cell Anemia is an example of a codominant inheritance. It mainly occurs in what ethnic group? Those of African descent

9. 8. What is the connection between sickle cell anemia and malaria
8. What is the connection between sickle cell anemia and malaria? Having sickle cell trait gives you an immunity to catching malaria

10. 9. Some forms of inheritance have more than 2 alleles
9. Some forms of inheritance have more than 2 alleles. These are called _________ ___________. Multiple alleles

11. 10. List the three alleles and four phenotypes for blood types
10. List the three alleles and four phenotypes for blood types. Phenotype Genotype Type O blood ii Type A blood IAi; IA IA Type B blood IBi; IB IB Type AB blood IA IB

12. 11. What does the presence of multiple alleles do to the possible number of genotypes and phenotypes? More genotypes increases the number of phenotypes

13. 12. What is epistasis? When one allele hides the effect of another allele; What example was used to explain it? ex. Labrador coat color

14. 13. What are the sex chromosomes for a male? XY For a female? XX

15. 14. What are autosomes? Body chromosomes– the first 22 pairs of chromosomes

16. 15. What is dosage compensation?
Only occurs in females—to avoid double dose of X chromosomes 1 deactivates. The deactivated x chromosome is called a Barr body.

17. 16. What are sex linked or x-linked factors
16. What are sex linked or x-linked factors? Traits found on the x chromosomes Which disorders are sex linked? Hemophilia and red green color blindness

18. 17. Why are males affected more frequently
17. Why are males affected more frequently? Because they receive only one X chromosome It comes from the mother

19. 18. What is a polygenic trait
18. What is a polygenic trait? A trait that is controlled by multiple pairs of genes What are some examples? Skin color, eye color, height

20. 19. What are two ways the environment influences phenotype
19. What are two ways the environment influences phenotype? Sunlight & temperature– could be many more

21. 20. Twin studies give us information on genetics by looking at identical twins. Why is this helpful? We can understand if a trait was caused by genetics or if it was environmental

22. Honors
21. Why are there fewer females who have red green colorblindness than males? Because they have 2 X chromosomes they are likely to have one dominant allele that masks the recessive allele

23. 22. Determine the genotypes of the parents if the father is blood type A, the mother is blood type B, the daughter is blood type O , one some is blood type AB and the other son is blood type B.
IAIi x IBIi

24. 23. Explain whether a male could be heterozygous for red-green colorblindness.
No, he only inherits one x chromosome

25. 24. What is the chance of producing a son with normal vision if the father is color blind and the mother homozygous normal for the trait? 100%