Question

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

Explanation:

To solve this, we analyze each option:

• Cytoplasm: The jelly - like substance within the cell where organelles are suspended, not for controlling substance entry/exit.
• Cytoskeleton: Provides structural support and helps in cell movement, not related to controlling substances.
• Cell membrane: It is a selectively permeable barrier. This means it allows certain substances to pass through while blocking others, so its main job is to control what enters and leaves the cell.
• Mitochondria: Known as the "powerhouse" of the cell, it is responsible for producing energy (ATP), not for controlling substances.

Answer:

cell membrane