How is a taxon (pl. taxa) defined ?

Explanation

**Step-by-Step Solution:**

1. **Understanding Taxonomy**: Begin by defining taxonomy, which is the science of classifying organisms based on shared characteristics and features.

2. **Classification Ranks**: Recognize that in taxonomy, organisms are organized into hierarchical categories or ranks. These ranks include kingdom, phylum, class, order, family, genus, and species.

3. **Definition of Taxon**: A taxon (plural: taxa) is defined as a unit of classification within this hierarchical system. It can represent any rank in the classification system, such as a kingdom or a species.

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