| True/False Indicate whether the sentence or statement is true or false. |
| 1. | Hemophilia is a recessive, sex-linked disorder. |
| 2. | An autosomal trait will occur with equal frequency in both males and females. |
| 3. | Sex-linkd traits appear more often in females than in males. |
| 4. | An individual who expresses a genetic disorder is called a carrier. |
| 5. | A male can produce sperm that contains either an X or a Y chromosome. |
| 6. | Mutations are always harmful. |
| 7. | A pedigree is a family record that shows how a trait is inherited over several generations. |
| Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. |
| 8. | Hemophilia is a genetic disorder that is a. | sex-linked. | c. | fairly common. | b. | sex-influenced. | d. | more common in women than in men. | | | | |
|
| 9. | Parents of a color blind female could have the genotypes a. | XCXc and XCY | c. | XCXc and XcY | b. | XcXc and XCY | d. | XCXC and XcY | | | | |
|
| 10. | People who are heterozygous for sickle cell anemia are a. | partially resistant to the effect of ultraviolet radiation. | b. | totally resistant to the effect of ultraviolet radiation. | c. | partially resistant to malaria. | d. | totally resistant to malaria. | | |
|
| 11. | Both sickle cell anemia and hemophilia a. | are caused by genes coding for defective proteins. | b. | are seen in homozygous dominant individuals. | c. | provide resistance to malaria infections. | d. | are extremely common throughout the world. | | |
|
| 12. | This genetic disease occurs most frequently in the black population. a. | cystic fibrosis | c. | sickle-cell anemia | b. | Tay-Sachs disease | d. | hemophilia | | | | |
|
| 13. | The trait for skin color in humans is cause by a. | crossing-over | c. | nondisjunction | b. | multiple genes | d. | mutations | | | | |
|
| 14. | A hereditary disease in which the red blood cells have an abnormal shape is a. | galactosemia | c. | polydactyly | b. | Tay-Sachs disease | d. | sickle-cell anemia | | | | |
|
| 15. | Sex-linked traits appear more often in males than in females because a. | males are produced in greater numbers | b. | females with a sex-linked trait will die | c. | males have only one X chromosome | d. | sex-linked traits are carried on the Y chromosome | | |
|
| 16. | A diagram in which several generations of a family and the occurrence of certain genetic characteristics are shown is called a a. | Punnett square. | c. | pedigree. | b. | monohybrid cross. | d. | family karyotype. | | | | |
|
| 17. | What is the percentage of chance that two people who carry a sickle-cell gene will have a child having the disease? |
| 18. | Which genetic trait is most influenced by the environment? a. | blood type | c. | baldness | b. | eye color | d. | weight | | | | |
|
| 19. | Very dark-skinned people have alleles at all gene positions for skin color that code for a. | red-green colorblindness. | c. | the production of Rh antigens. | b. | albinism. | d. | the production of melanin. | | | | |
|
| 20. | Sex-linked traits such as color blindness a. | are never carried by females | c. | occur more frequently in males | b. | occur more frequently in females | d. | never occur in males | | | | |
|
| 21. | What would be the blood type of a person who inherited an A allele from one parent and an O allele from the other? a. | type A | c. | type AB | b. | type B | d. | type O. | | | | |
|
| 22. | Genetic counseling is a process that a. | helps identify parents at risk for having children with genetic defects. | b. | assists parents in deciding whether or not to have children. | c. | uses a family pedigree. | d. | All of the above | | |
|
| 23. | If both parents carry the recessive allele that causes cystic fibrosis, the chance that their child will develop the disease is a. | one in two. | c. | two in five. | b. | one in four. | d. | 100 percent. | | | | |
|
| 24. | People with Down syndrome have a. | 45 chromosomes. | c. | 47 chromosomes. | b. | 46 chromosomes. | d. | no X chromosomes. | | | | |
|
| 25. | If nondisjunction occurs, a. | there will be too many gametes produced. | b. | no gametes will be produced. | c. | a gamete will receive too many or too few homologues of a chromosome. | d. | mitosis cannot take place. | | |
|
| 26. | A human female inherits a. | one copy of every gene located on each of the X chromosomes. | b. | twice as many sex chromosomes as a human male inherits. | c. | one copy of every gene located on the Y chromosome. | d. | all of the same genes that a human male inherits. | | |
|
| 27. | A pedigree CANNOT be used to a. | determine whether a trait is inherited. | b. | show how a trait is passed from one generation to the next. | c. | determine whether an allele is dominant or recessive. | d. | none of the above | | |
|
| 28. | If a man with blood type A and a woman with blood type B produce an offspring, what might be the offspring’s blood type? a. | AB or O | b. | A, B, or O | c. | A, B, AB, or O | d. | AB only | | |
|
| 29. | Sickle cell disease is caused by a a. | change in one DNA base. | b. | change in the size of a chromosome. | c. | change in two genes. | d. | change in the number of chromosomes in a cell. | | |
|
| 30. | Many sex-linked genes are located on a. | the autosomes. | b. | the X chromosome only. | c. | the Y chromosome only. | d. | both the X chromosome and the Y chromosome. | | |
|
