DNA MUTATION


Website:
http://www.genetichealth.com/G101_Changes_in_DNA.shtml
http://www.emunix.emich.edu/~rwinning/genetics/mutat.htm

There are many different types of mutation within the DNA. The first type of mutation is point mutation. This is when there is a change in one base of the gene sequence. The second type of mutation is called frame-shift mutation. This is when there are one or more bases are inserted or deleted. The third type of mutation is deletion and this is when there is a removal of one or more nucleotide pairs. The fourth type of mutation is insertion. This is when there is an addition of one more nucleotide pairs. The fifth type of mutation is inversion. This is when the entire section of DNA is reverse and it can occur to only a few bases within a gene or a large region of a chromosome. These mutations can cause missense mutation or nonsense mutation. Missense mutation has a wide range of effects. A nonsense mutation destroys the function of the gene product.

However, these mutations can cause one of these three effects on the organism. The first one is that there are overall no changes in organism. Another effect is that the organism is affected by the mutation which can either be a good thing or a bad thing. Mutation can also be lethal and it can kill the organism and give it no chances of survival. In conclusion, remember that missense and nonsense mutations are types of base-substitution mutations. A frameshift mutations results from insertion or deletion. These are the different classes of mutations that affect the base sequences of DNA, and the effects associated with each type of mutation.

external image frameshift.jpg
http://ghr.nlm.nih.gov/handbook/illustrations/frameshift.jpg
external image PointMutations.gif
http://www.ucl.ac.uk/~sjjgsca/PointMutations.gif