Describe how the binomial system is used to name organisms, and explain why this system is important for scientists worldwide.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
The scientific name is made up of two parts: the genus and the species.
The genus name is written first, with an initial capital letter, and the species name follows in lower case.
This binomial system is internationally agreed and universally used, so scientists worldwide can identify the same organism.
It avoids confusion and ambiguity because common names vary between regions or languages, whereas each species has only one unique scientific name.
The genus name is written first, with an initial capital letter, and the species name follows in lower case.
This binomial system is internationally agreed and universally used, so scientists worldwide can identify the same organism.
It avoids confusion and ambiguity because common names vary between regions or languages, whereas each species has only one unique scientific name.
Examiner tips
- Use the exact wording ‘genus’ and ‘species’ and note the capitalisation rule.
- Show the two‑part structure clearly – genus first, species second.
- Explain that the system is international and avoids confusion from common names.
Common mistakes
- Writing the species name with a capital letter or the genus in lower case.
- Using a single word or common name instead of the binomial.
- Failing to mention the international agreement or the avoidance of confusion.
Mark scheme (4 marks)
- The scientific name consists of two parts / is made up of genus and species
- The genus name is written first (with an upper-case first letter) and the species name second (in lower case)
- The system is internationally agreed / universally used so scientists worldwide can identify the same organism
- It avoids confusion / ambiguity because common names vary between regions or languages, whereas each species has only one unique scientific name
Key terms in this question
Related
- All Cambridge International IGCSE Biology (0610) revision notes →
- How to answer a "Describe" question →
- Decode the mark scheme abbreviations →
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