Question

select the part whose main job is to control which substances enter and leave the cell. chloroplast cell membrane ribosome cytoskeleton

Explanation:

The cell membrane is a selectively - permeable barrier. It regulates the movement of substances in and out of the cell. Chloroplasts are involved in photosynthesis, ribosomes in protein synthesis, and the cytoskeleton provides structural support and aids in cell movement.

Answer:

cell membrane