As the functions of individual genes become known, the power of this new biology can be used to change organisms in predictable and desirable pathways. Organisms which have been changed by the insertion of a cloned gene are called as transgenic organisms; transgenic plants and transgenic animals are both possible. Like approaches are not only of academic significance but are enhancing searching commercial applications. For instance, changed plants with better pest or virus resistance have general attractions for agriculture. Furthermore, there are most important ethical considerations which must be applied to the use of this latest technology both for plants and even more controversially, for animals (involving humans).