Gene Expression vs Mutations Gene Expression Every cell

Gene Expression vs. Mutations

Gene Expression Every cell in your body has the same DNA code but each cell only uses some of the genes. External factors (things in the environment or outside of the cell) activate (turn on and turn off) certain genes. When a gene turns on or off the expression of the gene is modified or changed.

What Gene Expression is NOT • The sequence of the DNA is NOT being changed • These changes are NOT permanent. The changes last as long as the organism is exposed to the environmental factor that is causing the gene to turn on or off

Gene Expression Example: Ice Pack When the ice pack is placed on the bunny, a black patch appears. What will happen once the ice pack (environmental factor) is removed?

Mutations • Definition: Mutations are changes in the sequence of DNA • Mutations can change the way in which a trait is expressed by an organism • However, not all mutations are bad

Did you know? • Mutations occur all the time in your DNA • Mutations that are not fixed then become permanent changes that can either benefit or harm the organism – Benefit: Cause variation that allows the organism to survive in a changing environment – Harm: Cause disease or death

Types of Mutations • There are essentially three types of mutations • 1. Deletions • 2. Insertions • 3. Substitutions