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. A point mutation or a frameshift mutation?
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
Nondisjunction- separate unevenly in meiosis

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. 23 homologous pairs 46 chromosomes
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. produces 4 genetically different sex cells but same chromosome number
Normal Meiosis:
produces 4 genetically different sex cells but same chromosome number

26. An uneven splitting of the chromosomes during meiosis
Nondisjunction
An uneven splitting of the chromosomes during meiosis

27. Nondisjuction Animation

28. Do the research Describe the syndrome List cause List symptoms
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 5-10 born each day in USA
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