1. Mechanisms for the Diversity of Life
Biology 1-4
Mechanisms for the Diversity of Life

2. 1-4A: Mutations
Genetic mutations can occur when a mistake is made in duplicating and transmitting genetic information.
Mutations can be beneficial (positive), harmful (negative) or unnoticed (neutral)

3. Examples of Mutations:
Examples of Positive Mutations:
Examples of Negative Mutations:
Examples of Neutral Mutations:

4. 1-4A: Mutations Mutations can happen in any type of cell.
Those that affect reproductive cells are called germ mutations and can be passed on to offspring
Those that affect other body cells are called somatic mutations and cannot be passed on.
Many cancers are caused by somatic mutations

5. 1-4A: Mutations
Both somatic and germ mutations can happen at two levels:
Chromosomal
Gene

6. 1-4A: Mutations
One example of a chromosomal mutation is trisomy 21 (also known as Down syndrome)
It occurs when there is an extra copy of the 21st chromosome

7. 1-4A: Mutations
Gene mutations can happen in different ways:

8. 1-4B: Mutagens
Mutagens are chemicals or other factors that can cause genetic mutations.
One example of this is a carcinogen, which is a mutagen that causes cancer.
Some carcinogens directly cause changes in DNA, and others simply affect cell division, increasing the chances that DNA mutations will occur

9. 1-4B: Mutagens Examples of carcinogens are:
Radiation (may be from radioactive substances or UV rays from the sun)
Chemicals in cigarettes such as benzene
Chemicals in food production, such as nitrites present in cured meats like bacon.