The term taxon is used to refer to the concrete biological objects included in a category.

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Taxon":**
- The term "taxon" refers to a group of one or more populations of organisms that are classified together in a taxonomic hierarchy.

2. **Taxonomic Hierarchy:**
- Taxonomy is the science of classification of living organisms. The basic levels of classification include:
- Species
- Genus
- Family
- Order
- Class
- Phylum
- Kingdom
- Each of these levels represents a category, and each category can be referred to as a taxon.

3. **Concrete Biological Objects:**
- The statement mentions "concrete biological objects included in a category." This means that a taxon consists of actual, identifiable organisms that fit within the defined category.

4. **Evaluating the Statement:**
- The statement claims that "the term taxon is used to refer to the concrete biological objects included in a category." Since a taxon indeed refers to specific groups of organisms classified within a certain category, the statement is accurate.

5. **Conclusion:**
- Therefore, the given statement is true.

**Final Answer:** True. The term taxon is used to refer to the concrete biological objects included in a category.

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