Carolus Linnaeus proposed a scientific system of naming organism in 1753. This system is named as binomial nomenclature. According to this system the scientific name consist of two parts. The first part is the name of genus and is called generic name which begins with a capital letter. The second part that follows the generic name specify the species and begin with a lower case letter. The binomial nomenclature of a frog is Rana tigrina. Rana is a genus and tigrina is the specie to which a frog belongs.