Which groups comprise the three domains of life?

Which groups comprise the three domains of life?

• A. Archaea, Bacteria, Eukarya
• B. Prokaryotes, Eukarya, Viruses
• C. Bacteria, Archaea, Fungi
• D. Plantae, Animalia, Protista

Answer: (A)

Classification of life is organized into three domains based on deep genetic relationships revealed by comparing molecular features like ribosomal RNA. The three domains are Archaea, Bacteria, and Eukarya. Archaea and Bacteria are both prokaryotes, meaning their cells lack a true nucleus, but they form distinct lineages with differences in membrane lipids, enzyme systems, and gene sequences. Eukarya includes organisms with eukaryotic cells that have a defined nucleus and internal organelles, such as plants, animals, fungi, and many protists. Viruses aren’t included because they are acellular and don’t constitute a form of cellular life. Within Eukarya, Plantae, Animalia, Fungi, and Protista are kingdoms or groups, but they’re all part of the single domain Eukarya, not separate domains.

Classification of life is organized into three domains based on deep genetic relationships revealed by comparing molecular features like ribosomal RNA. The three domains are Archaea, Bacteria, and Eukarya. Archaea and Bacteria are both prokaryotes, meaning their cells lack a true nucleus, but they form distinct lineages with differences in membrane lipids, enzyme systems, and gene sequences. Eukarya includes organisms with eukaryotic cells that have a defined nucleus and internal organelles, such as plants, animals, fungi, and many protists. Viruses aren’t included because they are acellular and don’t constitute a form of cellular life. Within Eukarya, Plantae, Animalia, Fungi, and Protista are kingdoms or groups, but they’re all part of the single domain Eukarya, not separate domains.