Identifiable physical location on a chromosome, the inheritance of which can be monitored. Antibiotic resistance marker genes (usually of bacterial origin) render cells "immune" to the antibiotic; these genes can be used as tools to identify plant cells that have received new DNA through genetic modification.
Organism that differs from its parent because of a mutation in its genetic code. Also called a variant.
Genetic change caused by natural phenomena or an agent that causes mutations (such as radiation). 'Stable' mutations in genes are passed on to an organism's offspring; 'unstable' mutations are not. [UCB]