GENE MUTATIONS (in DNA)  GENE MUTATIONS (in DNA)

Point Mutations Happen At Single Nucleotide Points in DNA  Point Mutations Happen At Single Nucleotide Points in DNA Substitution One base changes to (“subs” for) another Insertion Base added (inserted) Deletion Base removed (deleted)

The Dog Ate The Fat Cat Substitution Deletion Insertion The Dog Ate The Fat Rat Deletion The Oga Tet Hef Atr At.. Insertion The Dog Tat Eth Efa Tra t

What kind of point mutation? SUBSTITUTION

What kinds of point mutation? INSERTION DELETION

Insertions and Deletions Can Cause FRAMESHIFTS in the code!  Insertions and Deletions Can Cause FRAMESHIFTS in the code!  One nucleotide affected every codon down the line—a frameshift!

CHROMOSOMAL MUTATIONS (affect whole chromosomes)  CHROMOSOMAL MUTATIONS (affect whole chromosomes)

What Would You Call It? Deletion

One or more segment is repeated What Would You Call It? normal chromosome one segment repeated three repeats Duplication One or more segment is repeated

A linear stretch of DNA is reversed within the chromosome  What Would You Call It? Inversion A linear stretch of DNA is reversed within the chromosome

 What Would You Call It? chromosome nonhomologous chromosome reciprocal translocation Translocation Entire gene segments are exchanged between non-homologous chromosomes!

Check Point

Mutations may be:  Silent or neutral (no effect) Harmful or Fatal (bad effect) Beneficial (good effect, low probability)