Genetics Unit Test Study Guide

1. Distinguish between a dominant allele and a recessive allele

2. Distinguish between genotype and phenotype and give an example of both.

3. If A is dominant to A, what are the written genotypes of:

AA: Aa: aa:

4. What are homologous chromosomes?

5. What are the genotypic and phenotypic ratios of a monohybrid cross (both parents are heterozygous for a single trait):

Genotypic Ratio:

Phenotypic Ratio:

6. Define each one of the following Mendelian principles of genetics:

Law of Dominance:

Law of Segregation of alleles:

Law of Independent assortment:

7. What is meant by the “P” generation? The F1 generation? The F2 generation?

8. How does a genetic disease affect a patient who inherits it from the gene to protein level?

9. Describe each pattern of inheritance and provide an example for each:

Complete dominance

Incomplete dominance

Co-dominance

Genes with multiple alleles

Polygenic inheritance

Sex – linked inheritance

Sex-influenced inheritance

10. Distinguish between an autosomal dominant trait and an autosomal recessive and give a real life example of each.

11. Distinguish between sex linked recessive and sex linked dominant inheritance.

12. Which sex is more likely to inherit a sex linked recessive trait? Why?

13. Blood Type: What are all the patterns of inheritance blood types (including the A,B,O and the RH)? Complete the following table regarding blood type:

Blood Type All possible Genotypes

Antigen/s present on the surface of the cell

Antibodies produced in the presence of foreign antigen

Blood types that can be received by this blood type

A+

A-

B+

B-

AB+

AB-

O+

O-

14. Describe the basics of the following common human genetic disorders:Down syndrome

Huntington’s disease

Cystic Fibrosis

Sickle Cell Anemia

Hemophilia

Color Blindness

Baldness

15. Choose any one of Mendel’s pea plant traits. Show a single trait cross of the “P” generation: 16. Using the same trait you used in #15, cross 2 individuals of the F1 generation from the problem above.

17. What are all the possible phenotypes of the F2 generation from #16? What are all the possible genotypes? What are the genotypic and phenotypic ratios?

18. In Reebops two eyes is dominant to having only one (E and e respectively). Myopia (poor eyesight) is sex linked

recessive disorder carried on the X chromosome. (use M and m).

Once upon a time there was a female Reebop who had two eyes and didn’t have myopia while her father had one eye and myopia. She married a male Reebop who also had myopia and two eyes and a mother with one eye, what is the probability of them having a two – eyed boy with myopia? (show work)

What are the genotypes of the male and female Reebop?What is the genotype of the female’s father? What are two possible genotypes for the male’s mother?

19. Is Widow’s peak dominant or recessive? See the pedigree to the right:

20. The pedigree to the right traces the inheritance of alkaptonuria, a recessively inherited genetic disorder. Affected individuals, indicated by colored circles and squares, are unable to metabolize a substance called, alkapton, which colors the urine and stains the body tissues.

Fill in the genotype or genotypes for each family member. Hint: 3 of the individuals have two possible genotypes. Use A and a to represent the dominant and recessive alleles.

George __________ Arlene__________Sandra_________ Tom__________Sam__________ Wilma __________ Ann__________Michael__________ Daniel__________Alan__________ Tina__________ Christopher__________