What is a mutation

A Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene.Normally mutation is a natural process that changes a DNA sequence. But mutations can occur due to artificial reasons. And it is more common than you may think. As a cell copies its DNA before dividing, a "typo" occurs every 100,000 or so nucleotides. That's about 120,000 typos each time one of our cells divides. Most commonly, a single base is substituted for another. Sometimes a base is deleted or an extra base is added. Fortunately, the cell is able to repair most of these changes. When a DNA change remains unrepaired in a cell that will become an egg or a sperm, it is passed down to offspring. Thanks to mutation, we all have some new variations that were not present in our parents.

People commonly use the terms "mutant" and mutation" to describe something undesirable or broken. But mutation is not always bad. Most DNA changes fall in the large areas of the genome that sit between genes, and usually they have no effect. When variations occur within genes, there is more often a consequence, but even then mutation only rarely causes death or disease. Mutation also generates new variations that can give an individual a survival advantage. And most often, mutation gives rise to variations that are neither good nor bad, just different.

A Mutagen is an agent of substance that can bring about a permanent alteration to the physical composition of a DNA gene such that the genetic message is changed.Once the gene has been damaged or changed the mRNA transcribed from that gene will now carry an altered message.

The polypeptide made by translating the altered mRNA will now contain a different sequence of amino acids. The function of the protein made by folding this polypeptide will probably be changed or lost. In this example, the enzyme that is catalyzing the production of flower color pigment has been altered in such a way it no longer catalyzes the production of the red pigment.

No product (red pigment) is produced by the altered protein. In subtle or very obvious ways, the phenotype of the organism carrying the mutation will be changed. In this case the flower, without the pigment is no longer red.

Tweet