Which statement about bacteria is true?

Which statement about bacteria is true?

• A. They are single-celled prokaryotes whose cell walls are composed of peptidoglycan.
• B. They are eukaryotes with membrane-bound organelles.
• C. They lack a cell wall.
• D. They are photosynthetic only.

Answer: (A)

Bacteria are unicellular prokaryotes with cell walls containing peptidoglycan. This combination—single-celled organization without a nucleus and a wall built from peptidoglycan—is what distinguishes bacteria from eukaryotes, which have membrane-bound organelles, and from archaea, whose walls lack peptidoglycan. The presence of a peptidoglycan-containing cell wall is a defining feature for most bacteria and is the basis for how many antibiotics disrupt their growth by targeting cell wall synthesis. There are rare exceptions (such as some cell-wall–deficient bacteria), but in standard biology this description reflects the typical bacterial cell structure. The other statements—being eukaryotes with organelles, lacking a cell wall, or being exclusively photosynthetic—do not fit bacterial biology.

Bacteria are unicellular prokaryotes with cell walls containing peptidoglycan. This combination—single-celled organization without a nucleus and a wall built from peptidoglycan—is what distinguishes bacteria from eukaryotes, which have membrane-bound organelles, and from archaea, whose walls lack peptidoglycan. The presence of a peptidoglycan-containing cell wall is a defining feature for most bacteria and is the basis for how many antibiotics disrupt their growth by targeting cell wall synthesis. There are rare exceptions (such as some cell-wall–deficient bacteria), but in standard biology this description reflects the typical bacterial cell structure. The other statements—being eukaryotes with organelles, lacking a cell wall, or being exclusively photosynthetic—do not fit bacterial biology.