Which unicellular cell type lacks a nucleus and membrane-bound organelles but has ribosomes?

• A. Prokaryote
• B. Eukaryote
• C. Virus
• D. Fungus

Answer: (A)

Prokaryotes are the kind of unicellular cells that do not have a nucleus or membrane-bound organelles, yet they do have ribosomes to make proteins. Their genetic material sits in a nucleoid region, not inside a true nucleus, and they lack the internal compartments that characterize eukaryotic cells. This simple organization—no nucleus, no membrane-bound organelles, but ribosomes present—is the hallmark of prokaryotes, which include bacteria and archaea. In contrast, eukaryotes have a nucleus and various organelles, even when they are single-celled, and fungi are examples of unicellular eukaryotes. Viruses aren’t cells at all and don’t carry out protein synthesis with their own ribosomes.