DNA replication is carefully controlled to preserve the genetic information. However, changes in the genome do sometimes occur. These changes are known as mutations.
When a cell divides, the process of DNA replication is very carefully controlled to preserve the genetic information encoded within the nucleotide base sequence.
However, changes in the genome do occur. These are known as mutations. Mutations can have two results:
no protein is expressed
an altered protein is expressed
Some mutations can affect a few bases 鈥 these are single gene mutations. Some mutations can affect the structure of one or more chromosomes - these are chromosome structure mutations.