BOW 2 Semester 2 (Blog of the Week)

Sense mutation- this is sometimes seen with a single substitution mutation when the change in the DNA base sequence results in a new codon that is still coding for the same amino acid. (All amino acids are coded for by more than one codon.)

 Reference: http://www.mun.ca/biology/scarr/2250_Mutagenesis.html

Nonsense Mutations- the term "nonsense mutation is used because the stop codon has "no sense" for an amino acid. Nonsense mutations cause the protein to be cut off early and therefore incomplete, which usually renders it non-functional. Cystic fibrosis is a disease caused by a nonsense mutation.

Reference: http://www.drugs.com/cg/cystic-fibrosis.html

Deletion mutation- a type of gene mutation wherein the deletion (as well as addition) of a number of nucleotides cuases a shift in the reading frame of the codons in the mRNA, which may eventually lead to the alteration in the amino acid sequence at protein translation.

Reference: http://www.intelihealth.com/IH/ihtIH/WSIHW000/32193/32195/353894.html?d=dmtGenetics_BasicContent

Insertion Mutation- a type of mutation resulting from the addition of extra nucleotides in a DNA sequence or chromosome.

Reference: http://en.wikipedia.org/wiki/Insertion_(genetics)

Frameshift mutation- a type of gene mutation wherein the addition or deletion of a number of nucleotides causes a shift in the reading frame of the codons in the mRNA, which may lead to a change in the amino acid sequence in protein translation.

Reference:   http://ghr.nlm.nih.gov/handbook/illustrations/frameshift

 Point mutation - the simplest kind of genetic mutation, which can cause dramatic effects to arise from such a small substitution in the genome.

Reference: http://mahnaz-moleculargenetic.blogspot.com/2011/01/point-mutation.html

Translocation mutation- this happens when on of two homologous chromosomes breaks and binds to the other. Usually this sort of mutation is very dangerous.

Reference:  http://my.ilstu.edu/~ddwilso2/nur437/Genetics.htm