1. Mutations: Changes in Genes

2. Point Mutations
A point mutation is a change in a single base pair in the DNA.
Analogy:
THE CAT ATE THE RAT -original
THE BAT ATE THE RAT -point mutation

3. Example of a Point Mutation
Sickle cell anemia is caused by a single point mutation in the gene for hemoglobin (the protein that makes up red blood cells).
Sickle cell blood cell compared to normal blood cell

4. Not all point mutations result in defective proteins
Not all point mutations result in defective proteins. Example: may not change amino acid sequence.

5. Frameshift Mutation
Frameshift mutation: Insertion or deletion in a base. Shifts the codon pattern.
Analogy:
THE CAT ATE THE RAT- original
THE ATA TET HER AT - frame shift (C deleted)

6. Frame shift:
Changes the reading pattern of the 3 nucleotide codon sequence
Therefore, changes the entire amino acid sequence after the mutation.
Likely to be harmful.

8. Mutations can occur as random mutations during replication of DNA
Mutations can occur as random mutations during replication of DNA. Mutagens: Factors that make mutations more likely to occur. - UV Radiation - certain chemicals (carcinogens)