Biology · The Living World · NEET
| Full form | International Code of Botanical Nomenclature | International Code of Zoological Nomenclature |
| Governs names of | Plants (Botany) | Animals (Zoology) |
| Key middle letter | B = Botanical | Z = Zoological |
| Example organism | Mangifera indica (mango) | Panthera leo (lion) |
| Writing rules | Two words, Latin, italics, capital genus | Same: two words, Latin, italics, capital genus |
They are two different rule-books (Codes) for scientific names. ICBN sets the rules for naming plants (Botany). ICZN sets the rules for naming animals (Zoology). So the ONLY difference is the group they name: ICBN = plants, ICZN = animals. Both work to make sure every organism has one correct, worldwide-accepted name.
ICBN = International Code of Botanical Nomenclature. ICZN = International Code of Zoological Nomenclature. Read the middle letter: B stands for Botanical (plants), Z stands for Zoological (animals). The word 'Nomenclature' just means 'the system of naming'.
ICBN names ONLY plants. The B inside ICBN means Botanical, and botany is the study of plants. If a question asks which code gives names to plants, the answer is always ICBN. For animals you switch to ICZN.
Scientists worldwide agreed on universal rules and wrote them in these Codes. NCERT says biological names are governed by 'agreed principles and criteria' provided in the International Code for Botanical Nomenclature (ICBN). Animals follow the International Code of Zoological Nomenclature (ICZN). No single person can just invent a name; it must follow the correct Code.
Plants and animals were studied by two different groups of scientists (botanists and zoologists) for a long time. Each group built its own set of rules. So the naming of plants and animals is handled by two separate Codes. The good news for NEET: the naming style itself (two words, Latin, italics, capital genus) is the same in both.
Yes, the basic writing rules match. Under both Codes: the name has two words (genus + specific epithet), it is written in Latin, printed in italics (or underlined when handwritten), the genus starts with a capital letter, and the specific epithet starts with a small letter. The Codes mainly differ in WHICH group they govern, not in how you write the name.
Which of the following is against the rules of ICBN?
Nomenclature is governed by certain universal rules. Which one of the following is contrary to the rules of nomenclature?
Try the real previous-year questions from this chapter — each with the answer and a full solution.
For NEET, always answer ICBN. The 2011 update renamed it the International Code of Nomenclature for algae, fungi, and plants (ICN), but NCERT and NEET questions still use the older name ICBN. Write ICBN in your exam.
They are not covered by ICBN or ICZN. Bacteria follow a separate bacteriological code (ICNB) and viruses follow ICTV rules. But NEET Class 11 Chapter 1 only expects ICBN for plants and ICZN for animals, so focus on those two.
Read the middle letter only. B = Botanical = plants (ICBN). Z = Zoological = animals (ICZN). This one trick answers most direct questions on this topic.
No, the writing style is the same as for plants: two words, Latin, italics, capital genus, small specific epithet. ICZN just governs animal names, but the binomial format matches ICBN.
