Which of the following is NOT a listed level in the basic classification system presented?

• A. Kingdom
• B. Phylum
• C. Domain
• D. Class

Answer: (C)

In taxonomy, life is organized on a ladder of levels. The basic scheme you’re likely studying lists Kingdom, Phylum, Class, and then further ranks like Order, Family, Genus, and Species. Domain isn’t part of that traditional, foundational ladder; it’s a newer level added to reflect major genetic and cellular differences among organisms. In the three-domain system, life is grouped into Bacteria, Archaea, and Eukarya, with Domain sitting above Kingdom. Because the question refers to the basic levels presented, Domain isn’t included there, while Kingdom, Phylum, and Class are. For example, humans appear as Domain Eukarya, then Kingdom Animalia, Phylum Chordata, Class Mammalia, and so on.