Question

1. what is the main function of the cell membrane in both prokaryotic and eukaryotic cells?

a to synthesize proteins.
b to control the movement of substances in and out of the cell.
c to produce energy for the cell.
d to store genetic information.

Explanation:

The cell membrane is a selectively permeable barrier. It allows certain substances to enter or exit the cell while blocking others. This helps maintain the cell's internal environment.

• Option a: Protein synthesis occurs in ribosomes, not the cell membrane.
• Option c: Energy production (e.g., ATP synthesis) mainly happens in mitochondria (in eukaryotes) or through other cellular processes like glycolysis (in both prokaryotes and eukaryotes), not the cell membrane.
• Option d: Genetic information is stored in DNA, which is located in the nucleus (in eukaryotes) or the nucleoid region (in prokaryotes), not the cell membrane.

Answer:

B. To control the movement of substances in and out of the cell.