Types of Mutations

mutations

heritable changes in genetic information

point mutations

mutations that involve changes in one or a few nucleotides (bases); include substitutions, insertions, and deletions

substitutions

one base is changed to a different base

deletions

point mutations in which one base is deleted from the DNA sequence

insertions

point mutations in which one base is inserted into the DNA sequence

frameshift mutations

cause a shift in the reading frame of the genetic message; can alter the protein tremendously; examples: insertion and deletion

chromosomal mutations

a change in the number or structure of an entire chromosome; includes deletions, duplications, inversions, and translocations

deletion (chromosomal)

loss of all or part of a chromosome

duplication

produces an extra copy of all or part of a chromosome

inversion

reverses the direction of parts of a chromosome

translocation

occurs when part of one chromosome breaks off and attaches to another