WS 7-3: Human Genetic Disorders

Name______

On the line provided, write the letter of the term from the list that matches each description. Some can be used once, more than once, or not at all.

______1. disorder that causes a rapid breakdown of the a. albinism

nervous system beginning at age 2 or 3

b. cystic fibrosis

______2. process that takes place when a c'some pair

fail to separate correctly during meiosis c. Tay-Sachs disease

______3. form of trisomy in which there is an extra copy d. phenylketonuria

of c'some 21

e. Huntington disease

______4. disorder that results in lack of pigment in hair

or skin f. nondisjunction

______5. disorder caused by a recessive allele on c'some 7 g. trisomy

that results in fluid buildup in the lungs

h. Down syndrome

______6. Condition that exists when an individual is born

with cells that contain 3 copies of a c'some i. neurofibromatosis

______7. genetic disorder known as PKU, for which j. fragile-X syndrome

newborn infants in PA are tested

k. deletion

______8. process that occurs during meiosis when

pieces of c'somes break off and are lost

______9. disorder for which symptoms typically don't

appear until late 30s or 40s

______10. nervous system disorder that is most prevalent

in Jewish and French Canadian populations

______11. metabolic disease that if untreated can damage

the nervous system

______12. disease in which a skin spots may develop

into tumors

______13. disease that occurs mostly in males; when part

of the X c'come may be deleted

Directions: Place a check next to each accurate statement.

______14. The majority of genetic disorders are carried on the autosomes.

______15. Individuals with albinism are unable to produce the pigment responsible for most human skin color.

______16. cystic fibrosis is one of the least common fatal genetic disorders.

______17. Tay-Sachs disease is most common in families of South America.

______18. Sickle cell anemia is a blood disorder characterized by crescent shaped red blood cells.

______19. In the US, sickle cell anemia is most common among people whose families come from

Europe.

______20. PKU can cause severe mental retardation.

______21. Huntington is a rare dominant genetic disorder

______22. 1 in 100 births are affected by nondisjunction

______23. Turner syndrome affects only males.

______24. Men with Klinefelter's syndrome have an extra Y c'some.

______25. Down syndrome can result in circulatory problems.

Directions: Answer the following questions in the space provided.

26. What is a karyotype? Why would someone complete one? How are the c'somes arranged?

27. Why do you think that people with Turner and Kleinfelter's syndrome are unable to reproduce? (hint: analyze what they have for the sex c'somes)

28. What is the difference between a autosomal genetic disorder and a sex-linked disorder? Which one is more common and why?