Topic 9 - Genetic diversity and adaptation

• A mutation is known as any change to the quantity or the base sequence of the DNA in an organism.
• A gene mutation is known as a change to one or more nucleotide bases, or a change in the sequence of bases, in DNA.
• Gene mutations can arise spontaneously during DNA replication and include base substitution and base deletion.
• A substitution mutation involves a nucleotide in a DNA molecule being replaced by another nucleotide which has a different organic base.
• In a substitution mutation, the significance of the change in the polypeptide produced depends of the role of the original amino acid. For example, if the amino acid has a role in forming bonds in the tertiary structure, the replacement amino acid may not be able to form the same bonds.