1. Mutations We WILL: dEFINE MUTATIONS AND DESCRIBE THE DIFFERENT TYPES You Will: UNDERSTAND THE EFFECTS MUTATIONS CAN HAVE ON GENES

2. What Is a Mutation?
When cells make mistakes in copying their own DNA, inserting the wrong base or even skipping a base as a strand is put together.
The variations that occur are called mutations
The word mutation comes from the Latin word mutare, meaning “to change”
Mutations are heritable changes in genetic information.

3. Types of Mutations There are two basic categories for mutations:
Those that produces changes in a single gene (gene mutations)
Those that produces changes in the whole chromosome (chromosomal mutations)

4. Mutations can occur in both plants or animals.

5. Gene Mutations
Changes in one or more of the nucleotides are know as point mutations.
Point mutations include substitution, insertion, and deletion.
Point mutations generally occur during replication.

6. Frameshift
Insertions and deletions are referred to as frameshift mutations because they shift the “reading frame” of the genetic message.
Can change every amino acid that follows the point of mutation
Can alter a protein so much that it is unable to perform its normal functions.

7. Example of a Frameshift Disease
Tay-Sachs Disease
Develops at around 6 months of age
Nerves start deteriorating
Child becomes blind, deaf, and unable to swallow
Death usually occurs before the 4th year

8. Chromosomal Mutation
Involve changes in the number or structure of chromosomes
These mutations can change the location of genes on chromosomes and can even change the number of copies of some genes.

9. There are 4 types of chromosomal mutations
Deletion
Duplication
Inversion
Translocation

10. Harmful & Helpful Mutations
The effects of mutations on genes vary widely. Some have little or no effect; some produce beneficial variations. While some negatively disrupt gene function.
Mutations are often thought of as negative as they disrupt the normal function of genes. However, without mutations organisms could not evolve.

11. Harmful Effects
Some of the most harmful mutations are those that drastically change protein structure or gene activity.
Examples of harmful mutations
Sickle Cell Anemia
Change in RBC shape which deprives the body of oxygen
Cancer

12. Beneficial Effects
Mutations often produce proteins with new or altered functions that can be useful to organisms in different or changing environments.
Examples:
Mutations have allowed insects to resist chemical pesticide. (Bad for humans, good for insects)
Increase bone density, making fractures less likely
Some mutations can make individuals resistant to the HIV virus that causes AIDS.
Polyploid Plants

13. Polyploid Plants
Plant and animal breeders often make use of “good” mutations. (more often in plants than animals)
This condition means an organism has an extra set of chromosomes
Polyploid plants are often larger and stronger, good for crop farmers.