Name______

http://learn.genetics.utah.edu/content/chromosomes/karyotype/

1. What is a karyotype and how do they help scientists?

2. Is your karyotype a male or a female? How do you know?

http://www.dnaftb.org/8/ Click on Problem

3. What is the human diploid number? What is the human haploid number?

http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect16.htm

4. What is crossing over?

5. What does crossing over increase?

http://www.biologycorner.com/bio1/meiosis.html

6. What cells are created in spermatorgenesis?

7. What cells are created in oogenesis?

8. How is spermatogenesis different from oogenesis? (besides the cells that are created)

http://www.ygyh.org/ds/whatisit.htm

9. Is there a cure for Down Syndrome?

10. What is the cause of Down Syndrome?

11. About how many people have Down Syndrome?

http://www.ygyh.org/ds/cause.htm

Click Continue in the bottom right corner to find the answers.

12. How many chromosomes do people with Down Syndrome have? How many chromosomes do most people have?

13. Write down 2 of the physical traits that people with Down syndrome have.

14. What goes wrong in meiosis that causes Down Syndrome?

15. Which is more likely to be the cause of Down Syndrome the egg or the sperm?

16. What causes non disjunction (the most common cause of Down Syndrome)?

Karyotyping http://www.biology.arizona.edu/Human_Bio/activities/karyotyping/karyotyping.html

17. What process are the cells going through when you do a karyotype?

18.. Use the picture on the left to label the identifying features of a chromosome.

You will evaluate 3 patients' case histories, complete their karyotypes, and diagnose any missing or extra chromosomes. Click on “Patient Histories.” Read patient A’s history then click on “Complete Patient A’s Karyotype.”

Missing chromosome order for Patient A. (for example if the first chromosome matches the 20th pair write down 20 etc)

Patient A 1.______2.______3. ______4. ______5. ______

Answer the questions under "Interpreting the karyotype."

A1

A2

Same for Patient B. 1. ______2. ______3. ______4. ______5. ______6. ______7. ______8. ______

B1

B2

Patient C. 1. ______2. ______3. ______4. ______5. ______6. ______7. ______8. ______

C1

C2

http://learn.genetics.utah.edu/content/disorders/chromosomal/ Describe the chromosome abnormality and a few characteristics for each disease.

Syndrome / Chromosome Problem / Characteristics
Turner
Kline-felter
Cri du chat /
Williams

http://www.biologyinmotion.com/cell_division/index.html Click on Practice Meiosis & follow the directions