Which characteristic is shared by all bacteria and archaea?

• A. Presence of mitochondria
• B. Lack of a membrane-bound nucleus
• C. Linear chromosomes
• D. Cell walls composed of peptidoglycan

Answer: (B)

Verified step by step guidance

1. Understand the fundamental differences and similarities between bacteria and archaea, which are both prokaryotic domains of life.
2. Recall that both bacteria and archaea lack membrane-bound organelles, including a nucleus, which distinguishes them from eukaryotes.
3. Evaluate each option: mitochondria are membrane-bound organelles found only in eukaryotes, so they are not present in bacteria or archaea.
4. Linear chromosomes are typical of eukaryotes; bacteria and archaea usually have circular chromosomes, so this is not a shared characteristic.
5. Peptidoglycan is a component of bacterial cell walls but is generally absent in archaea, which have different cell wall compositions.