Name(s) ______________________________________________________ Date ___________________ Section _____
8th grade Science – SAMS
Genetic Disorders WebQuest
There are many inherited disorders in the human population. This WebQuest covers some of these genetic disorders. Using the
website listed below, along with your textbook, answer the following questions. Record your answers in the space provided. Be sure
to look at the pictures on the websites to assist in your understanding of these disorders.
http://learn.genetics.utah.edu/content/disorders/whataregd/
General Information:
1.
What is a genetic disorder?
2.
What kinds of abnormalities can lead to a genetic disorder?
3.
On this website, there are three ‘levels’ of disorders covered. Summarize what type of abnormality is associated with each
level.
 Level 1 – Single Gene Disorders:
4.
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Level 2 – Chromosome abnormalities:
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Level 3 – Multifactorial disorders:
What is a genetic counselor?
Single Gene Disorders:
Cystic Fibrosis (CF): http://www.ygyh.org/cf/whatisit.htm
5.
On what chromosome is the defective gene for CF?
6.
What are the major symptoms of cystic fibrosis and what causes them?
7.
How is CF inherited?
8.
What type of screening is done for CF?
9.
What treatments are available for CF?
Huntington’s disease (HD): http://www.ygyh.org/hd/whatisit.htm
10. On what chromosome is the defective gene for HD?
11. What are the major symptoms of HD and what causes them?
12. How is HD inherited?
13. What type of screening is done for HD?
14. What treatments are available for HD?
Phenylketonuria (PKU): http://www.ygyh.org/pku/whatisit.htm
15. On what chromosome is the mutation that causes PKU found?
16. What is the mode of inheritance of PKU?
17. What are the symptoms of PKU and what causes them?
18. How are infants tested for PKU?
19. How is PKU treated?
Hemophilia: http://www.ygyh.org/hemo/whatisit.htm
20. Where is the gene for Hemophilia located and how is it inherited?
21. What are the major symptoms of hemophilia and what causes them?
22. How is Hemophilia treated?
23. What is the connection between Hemophilia and HIV infection?
Chromosomal Abnormalities:
Down’s syndrome: http://www.ygyh.org/ds/whatisit.htm
24. What causes Down’s syndrome?
25. What are some symptoms of Down’s syndrome?
26. How is Down’s syndrome treated?
27. What is the incidence of Down’s syndrome?
Real World Examples: Case studies of Genetic Disorders
Read each Case Study and answer the questions that follow. Use the information you gathered from your WebQuest
along with your notes on Punnett squares and pedigrees to help with your discussions.
Case Study #1: Joshua and Bella
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Joshua and Bella have a son named Ian. Ian has been diagnosed with cystic fibrosis.
Joshua and Bella are both healthy
Both Joshua’s and Bella’s parents are both healthy.
Joshua’s sister, Sara, has cystic fibrosis.
1. What type of inheritance is cystic fibrosis an example of?
2. What are the genotypes for Joshua, Bella, and Ian? (Use N -normal and n – cystic fibrosis).
3. What are the possible genotypes of Bella’s parents?
4. What are the genotypes of Joshua’s parents and of his sister Sara?
5. Joshua also has a brother, Luke. What is the probability that he has cystic fibrosis?
6. Draw a pedigree to demonstrate this family history.
Case study #2: Andrew and Christine
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Andrew and Christine have three children: two boys, John and Joey, and one girl, Jenna.
Andrew has Hemophilia. Christine does not.
Neither John nor Joey has hemophilia, but Jenna is a carrier.
7. What type of inheritance is Hemophilia an example of?
8. What are the genotypes of John, Joey, and Jenna? (Use XN – normal and Xn – for hemophilia).
9. What is Andrew’s genotype? What are the possible genotypes for Christine?
10. If we know that Christine’s mother did not have hemophilia, but that her father DID, what would be Christine’s
genotype? Explain why.
11. Draw a pedigree to demonstrate this family history.