Define a taxon. Give some examples of taxa at different hierarchical levels.

Based on the sources, a **taxon** (plural: taxa) is the scientific term for the **convenient categories** we use to study organisms. Each category, which represents a rank or unit of classification in the taxonomic hierarchy, is referred to as a taxon. Taxa are considered **distinct biological entities** and not merely morphological aggregates.

Here are examples of taxa at different hierarchical levels mentioned in the sources:

* **General Examples:** Terms like ‘Plants’, ‘Animals’, ‘Dogs’, ‘Cats’, ‘Mammals’, ‘Wheat’, and ‘Rice’ are given as examples of convenient categories (taxa) used to study organisms. The sources explain that ‘animals’, ‘mammals’, and ‘dogs’ represent taxa at different levels.
* **Formal Taxonomic Categories:** The sources list common taxonomic categories developed from taxonomical studies of all known organisms, which represent different hierarchical levels. Each of these categories represents a taxon. Examples include:
* **Kingdom** (e.g., Animalia, Plantae)
* **Phylum** (for animals) / **Division** (for plants) (e.g., Chordata, Angiospermae)
* **Class** (e.g., Mammalia, Insecta, Dicotyledonae, Monocotyledonae)
* **Order** (e.g., Primata, Carnivora, Polymoniales, Diptera, Sapindales, Poales)
* **Family** (e.g., Solanaceae, Felidae, Canidae, Hominidae, Muscidae, Anacardiaceae, Poaceae)
* **Genus** (e.g., Solanum, Panthera, Felis, Homo, Musca, Mangifera, Triticum)
* **Species** (e.g., *indica*, *tuberosum*, *leo*, *tigris*, *nigrum*, *melongena*, *sapiens*, *pardus*, *domestica*, *aestivum*) – The source notes that the specific epithet is the second part of the binomial name and represents a particular species. Taxonomic studies consider a group of individual organisms with fundamental similarities as a species.

These examples illustrate how taxa represent different levels within the hierarchy of classification, from broad groupings like Kingdom to more specific groupings like Species or Genus.