Any change in the DNA base sequence is called a mutation Genetic Mutations Any change in the DNA base sequence is called a mutation

Why is the Tiger White DNA mRNAprotein Mutations are changes in the genetic code Some changes are lethal, and some don’t matter at all. (This tiger is white because of a genetic mutation)

Mutations in gamete cells mutation passed on to offspring Mutations in body cells damage to a gene = cell malfunction. New cells will also have malfunction

How do Mutations happen? Mutations: good, bad or neutral- most often neutral Spontaneous Nuclear radiation Ultraviolet light- sunlight Chemicals Mutagen- causes mutations

Decode this sequence mRNA ACU– GGA – CCA -- UUC Protein ____ _____ ____ ____ threonine glycine proline phenylalanine Now change just the last C to a G What do you get? leucine

A change of one base is called a point mutation mRNA ACU– GGA – CCA -- UUC threonine glycine proline phenylalanine Change the last C to a U- what happens? Sometimes point mutations don’t matter

Insertions and Deletions are Frameshift mutations mRNA ACU– GGA – CCA -- UUC Take out the first C AUG-- GAC– CAU– UC Meth ASP Hist ??? Called Frame shift mutations

Mutations Point mutations (substitutions)- may or may not be a big deal Frame shift mutations (insertions or deletions)- always a big deal

Example of a point mutation Sickle cell anemia One base change- one amino acid substitution Hemoglobin does not function normally