Which single-celled organism type is characterized by lacking a nucleus and membrane-bound organelles?

Which single-celled organism type is characterized by lacking a nucleus and membrane-bound organelles?

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

Answer: (A)

The key idea is how cells are organized based on the presence or absence of a nucleus and membrane-bound organelles. Prokaryotes have no nucleus and no membrane-bound organelles; their DNA sits in a nucleoid region and they lack compartments like mitochondria or chloroplasts. This distinguishes them from eukaryotes, which do have a true nucleus and membrane-bound organelles. While some fungi are unicellular, they are still eukaryotes with a nucleus and organelles. Viruses aren’t cells at all—they’re acellular particles that require a host to reproduce and don’t carry out cellular metabolism independently. So, the type that inherently lacks a nucleus and membrane-bound organelles is prokaryote.

The key idea is how cells are organized based on the presence or absence of a nucleus and membrane-bound organelles. Prokaryotes have no nucleus and no membrane-bound organelles; their DNA sits in a nucleoid region and they lack compartments like mitochondria or chloroplasts. This distinguishes them from eukaryotes, which do have a true nucleus and membrane-bound organelles. While some fungi are unicellular, they are still eukaryotes with a nucleus and organelles. Viruses aren’t cells at all—they’re acellular particles that require a host to reproduce and don’t carry out cellular metabolism independently. So, the type that inherently lacks a nucleus and membrane-bound organelles is prokaryote.