Key learning points

1. An example of a mutation in bacteria that could be helpful to humans (e.g. ability to digest man-made waste).
2. An example of a mutation in bacteria that is dangerous to humans (e.g. antibiotic resistance).
3. Explanations of examples at the genetic level using ideas about mutation, natural selection and asexual reproduction.
4. Explanations to include why advantageous genetic variants become more common in the bacteria over generations.

Keywords

• Natural selection - Organisms that are better adapted to their environment are more likely to survive, reproduce and pass on their genes to their offspring.

• Micro-organism - Microscopic living thing, such as a bacterium or an amoeba.

• Mutation - A change in the nucleotide base sequence in the DNA of the genome.

• Genetic variant - A region of DNA in which the sequence of nucleotide bases has been changed.

• Asexual reproduction - A form of reproduction in which a cell divides to produce two genetically identical cells.

Common misconception