Kinds of Mutations Point Mutation Occur at a single point in the DNA Changes in one or few nucleotides Substitutions – 1 base is changed to another Insertions – base is inserted into DNA Deletions – base is removed from DNA

Kinds of Mutations Frameshift Mutations Can alter a protein so much that it can’t perform it’s normal functions (shift the reading frame of the entire genetic message) Substitutions are not as detrimental as insertions or deletions because it only affects a single amino acid

Chromosomal Mutations Involve changes in the number or structure of chromosomes May change the locations of genes on a chromosomes

Significance of Mutations Most mutations are neutral, meaning they have little or no effect Source of genetic variability – highly beneficial Harmful mutations cause genetic disorders

Significance of Mutations Beneficial Mutations – may produce proteins that can be useful with changing environments Polyploidy – extra sets of chromosomes (plants are larger, stronger than diploid plants)

Gene Regulation Differentiation Cells because specialized in structure and function “hox genes” control the differentiation of cells and tissues in the embryo A mutation in these hox genes can affect how organs develop in the body