Answer :
The binomial system of nomenclature is a two- part scientific naming system. There are several
rules to follow when using the binomial system:
firstly, the genus comes first and begins with a capital letter,
secondly the species name follows and begins with a lower case letter. Thirdly,
both names are italicised and sometimes underlined. The ranks or categories of
genus and species have significance because they form the basis of the binomial
system. For example Homo (genus) sapiens
(species) (humans) and Macropus
(genus) giganteus (species) (Eastern grey kangaroo). The classification category, species, is the
lowest rank in the five kingdom system to which all organisms must be
classified.
The Genus, which is always capitalized and the species which is not.