1. Mutations

2. Mutations
Any change in the DNA structure (specifically the order of nitrogen bases) is a mutation.
Mutations can be helpful, harmful, or neutral.
Helpful – can create diversity in a population
Harmful – can cause things like cancer
Neutral – can have absolutely no effect at all
A mutagen is something that causes mutations in the DNA (for example: smoking, radiation from the sun etc)

3. Two Basic Mutation Categories:
1. Gene mutations
2. Chromosomal mutations
Produce changes in a single gene
Gene that produces the enzyme lactase doesn’t work correctly, and the person cannot digest lactose
Produce changes in a whole chromosome
Person inherits an entire extra chromosome, or is missing an entire chromosome
Person’s chromosome gets rearranged

4. Gene Mutations: Point Mutations
1. Substitution
2. Insertion or 3.Deletion
One base is changed to a different base
Usually only affects 1 amino acid, or has no effect
CCC changed to CCA
Still proline
CCC changed to ACC
Now threonine instead
Makes a totally different protein
One base is inserted or deleted from a sequence
Effects can be dramatic
*AKA: Frameshift mutations because they shift the sequence left or right
Can shift every amino acid that follows the mutation, causing BIG PROBLEMO!

5. Point Mutation Examples:
If our DNA was AATTGGCC
An insertion would be AATTAGGCC
A deletion would be AATGGCC
A substitution would be AAATGGCC

6. Guess the Mutation…
Substitution
Deletion
Insertion
Changing the DNA sequence changes the amino acid sequence, which changes the protein that is made, which CAN change the organism

7. Chromosomal Mutations:
Change # or structure of chromosomes:
Deletion – segment gets deleted
Duplication – segment gets duplicated
Inversion – 2 segments get switched
Translocation – part of one chromosome breaks off and attaches to another
Deletion
Duplication
Inversion
Translocation

8. Chromosomal Mutations
Types of Mutations
Chromosomal Mutations
Gene Mutations

9. Chromosomal Mutations
Types of Mutations
Chromosomal Mutations
Gene Mutations