Mutations+of+DNA

​ Mutations in DNA Everyone acquires some changes to their DNA during the course of their lives. These changes occur in many ways. Sometimes there are simple errors that are happen when DNA coppies itself. Other changes are introduced as a result of DNA damage through environmental agents including sunlight, cigarette smoke, and radiation. Our cells have built in mechanisms that catch and repair most of the changes that occur during DNA replication or from environmental damage. As get older, however, our DNA repair does not work as good and we accumulate changes in our DNA.  Some of these changes occur in cells of the body, such as in skin cells as a result of sun exposure, but are not passed on to children. But other errors can occur in the DNA of cells that produce the eggs and sperm. These are called germline mutations and can be passed from parent to child. If a child inherits a germline mutation from their parents, every cell in their body will have this error in their DNA. Germline mutations are what cause diseases to run in families, and are responsible for the kind of heredetary diseases covered by Genetic Health.



The Causes Of Mutations

Most of the mutations that we think matter to evolution are "naturally-occurring." For example, when a cell divides, it makes a copy of its DNA — and sometimes the copy is not quite perfect.That small difference from the original DNA sequence is a mutation.
 * 1. DNA fails to copy accurately **

** 2. External influences can create mutations ** Mutations can also be caused by exposure to specific chemicals or radiation. These agents cause the DNA to break down. This is not necessarily unnatural — even in the most isolated and pristine environments, DNA breaks down. Nevertheless, when the cell repairs the DNA, it might not do a perfect job of the repair. So the cell would end up with DNA slightly different than the original DNA and hence, a mutation.

The Effects Of Mutations Since all cells in our body contain DNA, there are lots of places for mutations to occur; however, some mutations cannot be passed on to offspring and do not matter for evolution. Somatic mutations occur in non-reproductive cells and won't be passed onto offspring. For example, the golden color on half of this Red Delicious apple was caused by a somatic mutation. Its seeds will not carry the mutation. The only mutations that matter to large-scale evolution are those that can be passed on to offspring. These occur in reproductive cells like eggs and sperm and are called germ line mutations.