Key Questions:

2. Key Questions: • How do mutations effect organisms?

4. DNA Mutation • Cells use 4 base pairs of DNA to make about 20 amino acids • These 20 amino acids combine to make up all the complex proteins in your body! • A single mistake or mutation in one base pair can lead to the wrong amino acid- that leads to a mutated protein

5. Possible Causes of DNA Mutations • Exposure to X-rays • Exposure to UV light • Exposure to certain chemical agents • Exposure to radiation

6. Mutations Point Mutation: Base pair substitution- replace base pair with another Frameshift Mutation: • Addition- add an extra base pair , change the reading frame • Deletion- take out a base pair, change the reading frame ACG  ATG ACG  ACC / G ACG  AG_

7. Which is worse? • Which would have a greater affect on the eventual protein/trait? A point mutation or a frameshift mutation?

8. Mutations • Point mutations and Frameshifts are mutations that change a portion of a DNA gene or RNA. • An error during what process would cause a mutation in the DNA? • An error during what process would cause a mutation in the RNA? Interphase- DNA replication Transcription or Translation

9. WHAT IF What if there is a mutation during MEIOSIS? Dun dun dun….

10. Chromosome Mutations • Nondisjunction- separate unevenly in meiosis • Translocations- part of chromosome moves to another chromosome

11. Chromosome Mutations • Deletion- part of chromosome deleted • Inversion- segment of chromosome inserted backwards

12. Human Chromosomes • Humans have 46 chromosomes normally. • 22 autosomes (2 of each) and 2 sex chromosomes (girls X___, boys X__)

13. Human Chromosomes • Humans have 46 chromosomes normally. • 22 autosomes (2 of each) and 2 sex chromosomes (girls XX, boys XY)

14. Karyotype • Karyotype- when scientists look at chromosomes and arrange them, and analyze them.

15. Karyotype • Arranged by size • Arranged by position of centromere • First arrange normal chromosomes • Try to arrange anything irregular

18. Staining chromosomes • Stain Giemsa Staining stains the A and T rich portion of DNA dark. • Banding patterns depend on genetic code • Banding patterns unique to certain chromosomes

19. Normal Karyotype 23 homologous pairs 46 chromosomes

20. What are the sex chromosomes ?

21. X and Y

22. Chromosomal notation: • 46,XY(normal boy) 46,XX(normal girl) • 47,XX,+21 ABNORMAL EXTRA 21 what’s the disease?

23. Down Syndrome 3 chromosomes (21st pair)

24. When Meiosis Fails

25. Normal Meiosis: produces 4 genetically different sex cells but same chromosome number

26. Nondisjunction An uneven splitting of the chromosomes during meiosis

27. Nondisjuction Animation

28. Do the research • Get into groups of 2-3 and research the following topics (each group needs a comp) • You will be assigned a syndrome • Describe the syndrome • List cause • List symptoms • Are their any treatments? • Interesting facts

29. Pericentric inversion of chromosome 9 • XYY Syndrome • Klinefelter’s Syndrome • Jacobsen Syndrome (Engnoth) • Bloom Syndrome (Nall) • Fanconi Anemia (NOT syndrome***) • Philadelphia Chromosome (Bompard) • Cri-du-chat syndrome (Kitzmiller) • Down Syndrome (**) • Turner Syndrome (Rinaudo) • Wolf-Hirschhorn Syndrome

30. Pericentric inversion of chromosome 9 • XYY Syndrome (Blye) • Klinefelter’s Syndrome (Carlton) • Jacobsen Syndrome • Bloom Syndrome • Fanconi Anemia (NOT syndrome***) (Phillips) • Philadelphia Chromosome (Wolfe) • Cri-du-chat syndrome • Down Syndrome • Turner Syndrome • Wolf-Hirschhorn Syndrome

31. Down Syndrome Karyotype 3 chromosomes (21st pair)

32. Down Syndrome Traits mental retardation epicanthal folds over eyes flattened bridge of the nose

33. Nondisjunction in Sex Chromosomes

34. Turner Syndrome: Missing X

35. Turner Syndrome Symptoms short stature sterile webbed neck skeletal disorders

36. XYY Syndrome Falsely called “superman” or “criminal” syndrome. 5-10 born each day in USA

37. XYY Symptoms taller more hairy heavy facial features delays in learning & language violent tendencies ????

38. Klinefelter Syndrome: XXY

39. Klinefelter Symptoms underdeveloped male traits mammary development learning disabilities language delays infertility