Question

what structure surrounds all cells and regulates passage of materials into and out of the cell?
o nucleoid
o cell membrane
o ribosome
o flagellum

Explanation:

The cell membrane is a selectively - permeable structure that surrounds all cells and controls the movement of substances in and out of the cell. The nucleoid is the region in prokaryotes where the genetic material is located. Ribosomes are involved in protein synthesis. Flagella are used for cell movement.

Answer:

B. cell membrane