There are so many kinds of a  patent  that differ from country to country. They may be anything from biological to business, chemical to software and industrial to a land patent. The rightful inventor in all has just one thing to prove, the useful application of the invention by him. There may be even a case of an invention of a plant kind, wherein the end result is just so inevitably useful to mankind. This way a patent may be applied by the inventor. Whatever be the kinds of patents are there, as far as the end result can be a useful application, it stands good.