1. Changes in DNA can cause changes in phenotype.
MUTATIONS
Changes in DNA can cause changes in phenotype.

2. Changes in the DNA sequence of nucleotides is called a mutation.
Some mutations have little or no effect on an organism, others are harmful or fatal, a few can even be beneficial.
There are two types of mutation:
1. Chromosomal - involves the entire chromosome.
2. Gene - involves individual genes on a chromosome.

3. 4 types of chrom. mutations:
Deletion - chromosome breaks apart, and a piece is lost.
Duplication - chromosome breaks apart, and the piece incorporates into the homologous chromosome.
Translocation - chromosome breaks apart, and the piece incorporates into a non-homologous chromosome.
Inversion - chromosome breaks and reattaches in reverse order.

5. There are 3 types of gene mutations:
Frameshift - deletion or insertion of nucleotides that disrupts codons.
Point or Substitution - change that occurs in only one nucleotide.

6. Cancer is uncontrolled, abnormal cell division
Caused when genes that control production of new cells do not shut off.
A gene that causes a cell to become cancerous is called an oncogene.

7. Three ways a gene can become an oncogene:
Mutation of a growth factor gene
An error in DNA replication
A change in a gene’s location