According to binomial nomenclature, two words used for naming a plant or animal are

Options

A. Species and genus
B. Genus and species
C. Species and family
D. Genus and family

Answer

### Step-by-Step Solution:

1. **Understanding Binomial Nomenclature**:
- Binomial nomenclature is a formal system of naming species by giving each a name composed of two parts.
- This system was developed by Carl Linnaeus and is used universally in the scientific community.

2. **Components of the Name**:
- The first part of the name is called the **genus**. It is always capitalized.
- The second part is called the **species**. It is written in lowercase.

3. **Example of Binomial Nomenclature**:
- For instance, the scientific name of the lion is *Panthera leo*.
- Here, *Panthera* is the genus name.
- *leo* is the species name.

4. **Identifying the Correct Answer**:
- The question asks for the two words used in binomial nomenclature for naming a plant or animal.
- Based on the definition and examples, the two words are **genus** and **species**.

5. **Conclusion**:
- Therefore, the correct answer to the question is **option 2: genus and species**.