MUTATIONS Changes in DNA that affect genetic information

Mutations  A change in the order of the nucleotide bases in DNA is a mutation  It can change the type of proteins a cell produces No freckles Freckles

Gene Mutations  Point Mutations – changes in one or a few nucleotides  Substitution  THE FAT CAT ATE THE RAT  THE FAT HAT ATE THE RAT  THE FAT CAT ATE THE RAT  THE BAT CAT ATE THE RAT

Gene Mutations  Frameshift Mutations – shifts the LETTERS of the genetic message so that the protein may not be able to perform its function.  Insertion  THE FAT CAT ATE THE RAT  THE FAT HCA TAT ETH ERA T  Deletion  THE FAT CAT ATE THE RAT  TEF ATC ATA TET GER AT H H

Insertion

Deletion

Chromosomal Mutations  Changes in number and structure of entire chromosomes

Chromosome Mutations  Deletion- loss of part or all of chromosome.  Duplication –extra copies or parts of chromosome.  Inversion-reverse direction of chromosome.  Translocation – occurs when chromosome breaks and attaches to another chromosome.

Types of Chromosomal Mutation: Deletion Original ABC * DEF ABC * DEF

Chromosome 5 Deletion: Cri du Chat Syndrome

Types of Chromosomal Mutation: Duplication ABBC * DEF Original ABC * DEF

Types of Chromosomal Mutation: Translocation Original ABC * DEF GHI*JKL ABC * JKL GHI * DEF

Chromosome 21 Duplication & Translocation: Down Syndrome

Types of Chromosomal Mutation: Inversion AED * CBF Original ABC * DEF

Significance of Mutations Most are neutralMost are neutral Eye colorEye color Birth marksBirth marks Some are harmfulSome are harmful Sickle Cell AnemiaSickle Cell Anemia Down SyndromeDown Syndrome Some are beneficialSome are beneficial Sickle Cell Anemia gives resistance to MalariaSickle Cell Anemia gives resistance to Malaria Immunity to HIVImmunity to HIV

What Causes Mutations?  Mutations can be inherited.  Parent to child  Mutations can be acquired.  Environmental damage  Mistakes when DNA is copied