Binomial nomenclature

In the syllabus and the exam

Binomial nomenclature is the standard two-word Latin naming system introduced so that every species has one internationally recognised scientific name, avoiding the confusion caused by common names that differ between languages and even between regions of the same country. Candidates must know the formatting rules precisely: the name is written in italics (or underlined if handwritten), the first word (the genus) always begins with a capital letter, and the second word (the species) is always written in lower case, even if it is derived from a person's or a place's name. A frequent error in structured answers is capitalising the species name or failing to italicise or underline the whole name, both of which are marked as formatting mistakes even when the correct name is otherwise known. Candidates are also expected to explain the benefit of this system directly, namely that a single, standardised scientific name prevents the ambiguity of common names, since the same organism may have several different common names, or a single common name may loosely refer to several different species, in different countries. Homo sapiens (modern humans) is the most frequently used example, and candidates should be comfortable applying the same two-part naming logic to any newly introduced organism in an unfamiliar exam question. Candidates should also recognise that the genus name alone may be abbreviated to its first letter followed by a full stop once it has already been written out in full earlier in the same answer, such as writing E. coli after first introducing Escherichia coli.

Example

In the scientific name Oryza sativa for rice, 'Oryza' is the genus name and 'sativa' is the species name, and both words are written in italics with only the genus name starting with a capital letter.

Related terms

SpeciesClassification

Source:SRC-DSKP-EN