Gene therapy: Treating genetic disease using healthy copies of the faulty allele

Gene: A length of DNA which codes for making one protein or polypeptide

Generic name: Name of the Genus; first part of a Latin name. Always has capital, e.g. Homo

Genetic Marker: An extra gene inserted into a plasmid that allows transformed bacteria to be recognised e.g. antibiotic resistance gene

Genome: The entire DNA sequences in an organisms chromosomes.

Genotype: The alleles an organism possesses. e.g. Aa or AA, AaBb or Aabb etc

Guard cells: Specialised epidermal cells surrounding the stoma. The cell walls contain radial microfibrils of cellulose, allowing them to change shape and bend when water is absorbed, thus opening the stoma.