Mutations occur naturally or through mutagens and create genetic variation; deleterious mutations are removed by natural selection while beneficial mutations accumulate, resulting in evolution. A gene is a segment of DNA defined by its base sequence; any change by addition, deletion, or substitution of bases disrupts the gene's function. Frameshift mutations from inserting or removing bases change a gene's reading frame, altering its translation entirely. Substitution mutations substitute one base for another within a gene.

1. Mutation

2. Gene Mutation Mutations occur naturally at random, but the rate of mutation is increased by mutagens such as radiation and some organic chemicals. Mutations create variation in the gene pool, and the less favorable (deleterious) mutations are removed from the gene pool by natural selection, while more favorable (beneficial or advantageous) ones tend to accumulate, resulting in evolutionary change.

3. Mechanism of Mutation Gene is a segment of DNA with a specific base pair sequence. This base sequence is like a sentence. Every word in this sentence has three words (three base pairs). Any change in the base sequence (by addition, deletion or substitution of bases) will make the gene meaningless. Such mutated genes cannot produce the desired proteins

7. Frame Shift Mutation Addition or deletion of one or more bases to a gene will result in frame shift mutations. This disrupts the reading frame, resulting in completely different translation

8. Substitution In substitution mutation, one base is substituted by another base.

9. Mutation Point mutations that occur within the protein coding region of a gene may be classified into three kinds, Silent mutations code for the same amino acid. Missense mutations code for a different amino acid. Nonsense mutations create new stop codons In the mRNA.