Period Name Date Karyotyping Activity Directions: In this activity, you will use a computer model to look at chromosomes and prepare a karyotype. You will diagnose patients for abnormalities and learn the correct notation for characterizing karyotypes. 1. What causes a dark band on the chromosome? Bases that have a lot of adenine and Thymine. 2. What is a centromere? The area where two chromatids joined. Patient Histories: Click on Patient Histories. You will be completing a karyotype for Patient A, B, and C. Patient A (Click on the link to "Complete Patient A's Karyotype") Match the chromosome to its homolog. After all the matches are complete, you will analyze your patient. (NOTE: Scroll down to the bottom of the page to view your completed karyotype). 3. Summarize the health history for patient A. Full term fetus of 40-year-old female 4. How many total chromosomes are in your karyotype? (Hint: actually count them.) 47 5. The last set of chromosomes are called the sex chromosomes, if you have two large chromosomes, your patient is XX (female), one large and one small indicates XY (male). What type of sex chromosomes does this patient have? XX 6. Which chromosome set has an extra chromosome? Y 7. What notation would you use to characterize Patient A’s karyotype? 47 XXY 8. What diagnosis would you give this patient (what disease)? Explain. Down syndrome Patient B - click on the link to go to Patient B and repeat the above process. 9. Describe the health history for patient B. 28-year-old infertile male 10. How many total chromosomes are in your karyotype? (Hint: actually count them.) 47 11. What sex chromosomes does your patient have? XXY 12. Which chromosome set has an extra chromosome? X 13. What notation would you use to characterize Patient B’s karyotype? XXXY 14. What is the diagnosis for this patient? Explain. Klinefelter syndrome Patient C - click on the link to go to Patient C and repeat the above process. 15. Describe Patient C’s health history. Died shortly after birth 16. How many total chromosomes are in your karyotype? (Hint: actually count them.) 47 17. What sex chromosomes does your patient have? XXY 18. Which chromosome set has an extra chromosome? X 19. Write out the correct notation for this karyotype. 47 XXYY 20. What is the diagnosis for this patient? Explain. Trisomy 13