Geoff G. answered • 04/30/21
Extensive Experience Editing and Proofreading Formal Papers
In the most basic sense, a mutation is a change in the DNA sequence. Remember that the DNA molecule consists of 3 main components - the "sugar-phosphate backbone" itself consisting of two parts (a 5-carbon sugar (deoxyribose) and a phosphate group) along with a nucleotide. The nucleotides are molecules containing nitrogen and are the "letters" we associate with DNA (A-G-T-C). The DNA molecule is formed when the nucleotides of two parallel strands (i.e. backbones) are bound to each other.
The sequence of nucleotides in DNA is a code - the sequence can be "read" by cells and this reading results in the production of the various proteins that make up the structure of your body. If the sequence of nucleotides is altered, changes *may* result in the proteins that are produced when DNA is copied and read during cell division.
The change might occur at any time - exposure to radiation for example can cause alterations or DNA, or changes to the sequence may occur during the process of copying and preparing DNA to be read which happens when cells divide (note that cells are dividing all the time under normal circumstances in humans). Various types of mutations can occur. Nucleotides can be added or deleted to the sequence or one can simply be swapped out for another.
The effects of mutations are widely variable - on one extreme there might be no changes at all to the proteins the cell produces and at the other extreme there might be disastrous consequences with one or more proteins being formed incorrectly or not produced at all. Between these extremes there might be very slight changes to the shape of the protein - these include the beneficial mutations that allow natural selection to improve the design of organisms and actually increase their survival in their environment. However, the odds are that any given mutation is likely to be bad for the organism.
