Explain how a mutation can happen and give an example.
A mutation is a change that occurs in the DNA sequence of an organism. It can happen due to various factors such as errors during DNA replication, exposure to certain chemicals or radiation, and even environmental factors.
One example of a mutation is the substitution mutation. In this type of mutation, one nucleotide base is replaced by another in the DNA sequence. For instance, a DNA sequence may have the bases A-T-C-G. However, due to an error during replication or exposure to a mutagen, the base T is replaced by the base G, resulting in the DNA sequence A-G-C-G. This change can alter the genetic code and potentially result in a different protein being produced.
This mutation can have several effects. It may be silent if the altered codon still codes for the same amino acid. Alternatively, it can be a missense mutation, where the altered codon codes for a different amino acid, potentially affecting the structure and function of the protein. In some cases, the mutation can be a nonsense mutation, where the altered codon becomes a stop codon, resulting in an incomplete and nonfunctional protein.
Overall, mutations are essential for genetic diversity and evolution. They can lead to new traits, adaptations, and even diseases.