Define a taxon. Give some examples of taxa at different hierarchical levels.
A taxon represents a unit of classification. It refers to a rank or category within the taxonomic hierarchy. These taxonomic groups are distinct biological entities and not merely morphological aggregates.
Taxa can indicate categories at very different hierarchical levels. For example, 'Animals', 'Mammals', and 'Dogs' are all taxa. Similarly, 'Wheat' and 'Plants' represent taxa. These examples show that a dog is a mammal and mammals are animals, meaning they represent taxa at different levels of classification.
Explanation
The answer defines 'taxon' using the direct definition provided in the first context chunk ('unit of classification', 'rank or category'). It then uses the specific examples listed in the fourth context chunk ('Animals', 'Mammals', 'Dogs', 'Wheat', 'Plants') to illustrate the concept of hierarchical levels. The explanation clarifies that these groups are distinct biological entities.