1. Mutations

2. What Are Mutations? Changes in the nucleotide sequence of DNA
May occur in somatic cells (aren’t passed to offspring)
May occur in gametes (eggs & sperm) and be passed to offspring

3. Are Mutations Helpful or Harmful?
Some mutations may improve an organism’s survival (beneficial)

4. Types of Mutations

5. Gene Mutations Change in the nucleotide sequence of a gene
May only involve a single nucleotide
May be due to copying errors, chemicals, viruses, etc.

6. Types of Gene Mutations
Include:
Point Mutations
Substitutions
Insertions
Deletions
Frameshift

7. Point Mutation Change of a single nucleotide
Includes the deletion, insertion, or substitution of ONE nucleotide in a gene

8. Point Mutation Original: THE FAT CAT ATE THE RAT Mutation:
Substitution -
Insertion -
Deletion -

9. Frameshift Mutation
Inserting or deleting one or more nucleotides – a specific type of point mutation that can change the created protein.
Changes the “reading frame” like changing a sentence
Proteins built incorrectly

10. Original: Mutation: Frameshift Mutation Frameshift -
THE FAT CAT ATE THE RAT
Mutation:
Frameshift -

11. Amino Acid Sequence Changed

12. Chromosome Mutations May Involve:
Changing the structure of the chromosome
of a chromosome
loss or gain of part of the chromosome of part of a chromosome

13. Chromosome Mutations Several types exist: Deletion Inversion
Duplication

14. Deletion
Due to breakage
A piece of a chromosome is lost

15. Inversion
Chromosome segment breaks off
Segment flips around backwards
Segment reattaches

16. Duplication
Occurs when a gene sequence is repeated

17. FYI

18. Normal Male
2n = 46

19. Normal Female
2n = 46

20. Male, Trisomy 21 (Down’s)
2n = 47

21. Female Down’s Syndrome

22. Klinefelter’s Syndrome

23. Turner’s Syndrome
2n = 45