1. Changes in DNA can produce variation
Section 5.2

2. DNA sequence can change
Differences in DNA are what make one organism different from another
The number of differences between two species is large
Human
3 billion
Base pairs
Yeast cell
12 Million
Base Pairs

3. DNA sequence can change
The number of differences between 2 individuals of the same species is small
(<0.1% variation)

4. DNA sequence can change
There is a large number of DNA bases in any organism that need to be copied
Errors can occur when DNA is copied or affected by environment
UV radiation
X-rays
Toxins

5. DNA sequence can change
Mutation – any change in DNA
Cells have ways of fixing mistakes in DNA
However some mistakes are not fixed

6. Possible outcomes when error occurs in genes
No effect
Some amino acids have more than one
code and may not change resulting protein
May have enough protein being produced

7. Possible outcomes when error occurs in genes
Mutation is minor
May only cause a change in appearance

8. Possible outcomes when error occurs in genes
Mutation is great
Could be good (Resistant to disease)
Could be bad (genetic disorder or disease)

9. Only 5% of human DNA is in genes
If mutation occurs in a non-coding region, then chances are that the mutation is neutral

10. Genetic Disorders
Disease or condition caused by mutations that affect normal functions of the cell
Can be inherited (Tay-Sachs)
Can occur during a person’s life (Cancer)

11. Genetic Disorders A person can carry a tendency for a disease
(diabetes)
Sometimes a person’s
behavior can prevent
the disease (smoking)

12. Genetic Disorders Mutations can have more than one effect
Sickle cell anemia
Recessive disorder
Prevents blood from carrying oxygen
Prevents malaria

13. Genetic Disorders
Pedigree – shows a family relationship for 2 or more generations

14. Cancer A group of disorders
Characterized by uncontrolled division of cells
Cells can spread to other tissues
Causes
Inherited
Carcinogens
Radiation
Series of mutations