Question

1. which of the following is a feature unique to eukaryotic cells?

a. presence of ribosomes
b. presence of membrane - bound organelles.
c. cytoplasm for metabolic reactions.
d. semi - permeable cell membrane.

Explanation:

• Option a: Both prokaryotic and eukaryotic cells have ribosomes. Prokaryotes use them for protein synthesis in the cytoplasm, and eukaryotes have them in the cytoplasm and on the rough endoplasmic reticulum.
• Option b: Membrane - bound organelles (such as mitochondria, endoplasmic reticulum, Golgi apparatus, etc.) are unique to eukaryotic cells. Prokaryotic cells lack these complex, membrane - enclosed structures.
• Option c: Both prokaryotic and eukaryotic cells have cytoplasm where metabolic reactions occur. In prokaryotes, many metabolic pathways (like glycolysis) take place in the cytoplasm, and in eukaryotes, while some reactions are in organelles, the cytoplasm still has metabolic functions (e.g., part of protein synthesis initiation).
• Option d: Both prokaryotic and eukaryotic cells have a semi - permeable cell membrane that controls the movement of substances in and out of the cell.

Answer:

B. Presence of membrane - bound organelles.