Gene mutation is also called point mutations. These mutations occur because of changes in the DNA base sequence or it can be said as nucleotide changes in DNA. A body synthesized proteins derived from readings of three base pairs (triplets). Each triplet codon carried a sense of the DNA chain. Triplet is a reading that is understandable by the body to produce amino acids. Gene mutations can be divided into two, namely the replacement of base pairs, insertion, and deletion of base pairs (Campbell, 1998: 318).
a. Replacement Pair of Bases
Replacement of base pairs is the substitution of one nucleotide with another nucleotide.Replacement of this base to create a mutant organism. In general, harmful mutations organism that undergoes them.
In Picture 1, a base A (purine base) replaces the base G (purine base) in the fourth codon of the mRNA. Replacement of this base to give effect to the organism or not at all. This, depending on how the replacement base is translated. For example, if the mutation causes the codon on the mRNA sequence of bases changed from GAA to GAG. Replacement of the base sequence, does not cause changes in the protein because the base sequence GAA and GAG is the same code for amino acid glutamate.
Normal hemoglobin DNA Mutated hemoglobin DNA