Chapter 12: Patterns of Heredity and Human Genetics

1. People who have ancestors from which of these countries typically have a higher incidence rate

of PKU?

a. Greece

b. England

c. Sweden

d. South Africa

2. When making a pedigree, which of these symbols is used to represent an affected male?

a.

b.

c.

d.

3. A child is born to a mother with blood type IAIB and a father with blood type IBi. Which of the

following blood types is impossible for the child to have?

a. A

b. AB

c. O

d. B

4. According to this Punnett square, what is the chance that a human offspring will be male or

female?

a. 25%

b. 100%

c. 50%

d. 75%

5. Which of these statements about Huntington's disease is true?

a. There is currently no effective treatment of Huntington's disease.

b. Huntington's disease is caused by the expression of a recessive allele.

c. The onset of Huntington's disease is typically between birth and three years of age.

d. Genetic tests to detect the presence of the allele responsible for Huntington's disease

do not exist at this time.

6. Which of these statements is true?

a. Temperature plays a role in the color of the fur of the arctic fox.

b. Premature balding is a dominant gene in human males and females.

c. The color of a peacock's feathers is always the same as the color of a peahen's

feathers.

d. Traits for human skin color are governed by only one gene.

7. Traits that are controlled by genes found on the sex chromosomes are __________.

a. heterozygous

b. autosomes

c. sex-linked traits

d. polygenic inheritance

8. Which of these could be the blood type of a child with a father of blood type IAIA and a mother

of blood type IAIA ?

a. B

b. O

c. A

d. AB

9. Which of these is NOT an example of a simple dominant trait?

a. a cleft chin

b. a hitchhiker's thumb

c. a widow's peak hairline

d. cystic fibrosis

10. What is polydactyly?

a. A condition characterized by having the absence of an enzyme that converts

phenylalanine to tyrosine.

b. A condition characterized by the accumulation of lipids in cells.

c. A condition characterized by having six fingers.

d. A condition characterized by the formation and accumulation of thick mucus in the

lungs and digestive tract.

11. What can you determine by studying this karyotype?

a. The person is a male with Down syndrome.

b. The person is a female with Turner syndrome.

c. Some of the chromosomes are curved, so this person has sickle-cell disease.

d. The person is a male with hemophilia.

12. Which of these is a symptom of hemophilia?

a. cuts that take a long time to stop bleeding

b. some degree of mental retardation

c. inability to differentiate between shades of red and green

d. tissue damage from blocked blood flow

13. Which of the following is NOT true?

a. A karyotype is a chart of chromosome pairs generated on a computer.

b. Queen Victoria of England was a carrier of the sex-linked trait for hemophilia.

c. Males inherit the allele for hemophilia on the Y chromosome from their mother, if she

is a carrier.

d. Sickle-cell disease causes abnormal red blood cells, shaped like sickles, to block small

blood vessels.

14. Which of these statements is NOT true?

a. Human males produce two kinds of gametes, called X and Y.

b. The 23rd pair of chromosomes are exactly the same in human males and females.

c. If you are a female, your 23rd pair of chromosomes are XX.

d. Homologous autosomes look alike.

15. __________ cause the phenotypes of both homozygotes to be produced in heterozygous

individuals.

a. Codominant alleles

b. mutations

c. Incomplete dominances

d. Environmental influences