A. changes in nucleotides of a dna molecule that affect the genetoc message
B. reduction in the rate of repillication of dna due to regulatory mechanisms
Mutations are changes in the nucleotide sequence of a DNA molecule that can affect the genetic message carried by that DNA. These changes can occur spontaneously or as a result of exposure to certain external factors, such as radiation or chemicals. Mutations can range from small changes involving a single nucleotide to larger changes involving multiple nucleotides or even entire genes. These changes can have a variety of effects on an organism, ranging from no impact at all to causing diseases or other genetic disorders. Mutations are an important source of genetic diversity and can play a key role in evolution by providing the genetic variation upon which natural selection can act.
