One ethical issue arising from keeping DNA on a DNA database is, you are not certain who can access these records,insurances companies and employers may want access.
However DNA databases may be useful for several reasons such as identifying victims and dead bodies, and also police will be able to identify suspects if they have committed a crime by comparing their DNA to the DNA found at the scene of the crime.
Scientists can tell how closely related two organisms are by comparing their DNA. This is DNA hybridisation. Scientists also use morphological features to group living things.
Every organism has a scientific name, this is so all scientist will recognise this name internationally,the scientific name is always the same in every country and language.
All organims have a unique set of genes with the exception of genetically identical twins and clones.