In the three-domain system (Bacteria, Archaea, Eukarya), which domain contains organisms whose cells typically have a membrane-bound nucleus?

• A. Eukarya
• B. All three domains
• C. Bacteria
• D. Archaea

Answer: (A)

Verified step by step guidance

1. Understand the three-domain system, which classifies all life into Bacteria, Archaea, and Eukarya based on cellular and genetic characteristics.
2. Recall that a membrane-bound nucleus is a defining feature of eukaryotic cells, where the genetic material is enclosed within a nuclear envelope.
3. Recognize that Bacteria and Archaea are prokaryotes, meaning their cells lack a membrane-bound nucleus; their DNA is free-floating within the cell.
4. Identify that the domain Eukarya includes all organisms with eukaryotic cells, which have membrane-bound organelles including the nucleus.
5. Conclude that the domain containing organisms with cells that typically have a membrane-bound nucleus is Eukarya.