1. Can you guess what these are?

2. That’s right…they’re Chromosomes! We can arrange chromosomes into homologous pairs in a karyotype to detect abnormalities that may cause genetic disorders.

3. Colchicine added to cells Cells broken open Microscope zooms in Picture of chromosomes taken Chromosomes cut up and arranged And how do scientists do this, you may ask…

4. Can you pick out the homologous pairs? How did you identify them? Chromosome = “colored body”

5. What is happening here?

6. Answer: Amniocentesis – the process of removing amniotic fluid from the uterus of a pregnant woman to diagnose any genetic disorders prior to the baby’s birth. Here’s how it works…

7. Normal MaleNormal Female Downs SyndromeTurner’s Syndrome Trisomy 13 Klinefelter’s Syndrome Let’s look at some examples of karyotypes and their corresponding health conditions… Williams SyndromeCri du Chat Syndrome Continue

8. Back Identify by XY for chromosome pair 23

9. Back Identify by XX for chromosome pair 23

10. Where is the chromosomal abnormality? Trisomy 21

11. Back Downs Syndrome

12. Where is the chromosomal abnormality? Monosomy X

13. Back Turner’s Syndrome

14. Where is the chromosomal abnormality? Trisomy 13

15. Back Trisomy 13 aka Patau Syndrome

16. Where is the chromosomal abnormality? XXY on chromosome 23

17. Back Klinefelter’s Syndrome

18. Williams Syndrome is due to a deletion on chromosome 7. This abnormality is too small to identify on most karyotypes, so fluorescent probes must be used.

19. Williams Syndrome The missing genes code for a protein that makes blood vessels elastic Results in problems with the cardiovascular system Back

20. Can you find the chromosomal difference?

21. Cri du Chat Syndrome Detected by a deletion on chromosome 5 Symptoms: –Abnormal larynx development –Problems with respiratory system –High-pitched cry sounds like a cat 80% come from father’s sperm Back

22. Want some more practice? Click the link below to do an interactive karyotyping activity: –Predicting with KaryotypesPredicting with Karyotypes