Question

which cellular structure is associated with eukaryotic cells but not with prokaryotic cells?
○ cell wall
○ dna
○ nucleus
○ cell membrane
○ ribosomes

Explanation:

1. Analyze each option:

• Cell wall: Present in some prokaryotes (e.g., bacteria) and some eukaryotes (e.g., plants, fungi), so not unique to eukaryotes.
• DNA: Both prokaryotic and eukaryotic cells have DNA (prokaryotes have circular DNA in the nucleoid, eukaryotes have linear DNA in the nucleus), so not unique.
• Nucleus: Eukaryotic cells have a membrane - bound nucleus that encloses genetic material. Prokaryotic cells do not have a nucleus (their genetic material is in the nucleoid region without a membrane).
• Cell membrane: Both prokaryotic and eukaryotic cells have a cell membrane that controls the movement of substances in and out of the cell.
• Ribosomes: Both prokaryotic and eukaryotic cells have ribosomes for protein synthesis (though prokaryotic ribosomes are smaller, 70S, and eukaryotic are 80S).

Answer:

C. nucleus