1. Mutations change in the DNA or RNA sequence May result in new alleles
Important for evolution
Can be beneficial or harmful
May be spontaneous (due to mistakes during transcription/translation or mitosis/meiosis)
May be environmentally endued!
There are also chromosomal mutations, large changes with dramatic effects.

2. chromosomal alterations
Types of Mutations
point mutations
frameshift mutations (Mutations that disrupt the reading frame by insertions or deletions of a non- multiple of 3 nucleotide bases.)
chromosomal alterations

3. Beneficial Mutations
They lead to new versions of proteins that help organisms
adapt to changes in their environment.
essential for evolution
increase an organism’s chances of surviving or reproducing
Example: Mutations in many bacteria that allow them to survive in the presence of antibiotic drugs.
The mutations lead to antibiotic-resistant strains of bacteria.
Wolverine, from X-Men, has a mutation that causes his cells to repair themselves very quickly. This allows him to get up after an injury and continue to do good. It also gives him the appearance that he doesn’t age.

4. Harmful Mutations
When a mutation alters a protein that plays a critical role in the cell it may not function properly, resulting in a medical condition.
Harmful mutations may cause genetic disorders or cancer.
A genetic disorder is a disease caused by a mutation in one or a few genes.
Example: cystic fibrosis. A mutation in a single gene causes the body to produce thick, sticky mucus that clogs the lungs and blocks ducts in digestive organs.
Cancer is a disease in which cells grow out of control and form abnormal masses of cells.
It is generally caused by mutations in genes that regulate the cell cycle. Because of the mutations, cells with damaged DNA are allowed to divide without limits. Cancer genes can be inherited.

5. Cancer Mutations Cancer is caused by a series of mutations
Cells have developed a number of control mechanisms to overcome mutations
A mutation in one proto-oncogene would not cause cancer
effects would be masked by mitosis and tumor suppressor genes.
Signals for cell growth overwhelm the signals for growth regulation, and the cell quickly
spirals out of control
(Often, because many of these genes regulate the processes that
prevent most damage to the genes themselves, DNA damage accumulates as one ages.)
Cancers are caused by a series of mutations. Each mutation alters the behavior of the cell.
For example, the first mutation inactivates a tumor suppressor gene, the second mutation
inactivates a DNA repair gene, the third mutation creates an oncogene, and a fourth
mutation inactivates several more tumor suppressor genes, resulting in cancer.