Question

select the true statements.
only animal cells have a cell membrane.
the cell membrane is rigid.
the cell membrane controls what enters and exits a cell.
the cell membrane maintains a separate environment inside a cell.

Explanation:

• Only animal cells have a cell membrane: This is false. All cells (plant, animal, bacterial etc.) have a cell membrane. Plant cells also have a cell wall in addition to the cell membrane.
• The cell membrane is rigid: This is false. The cell membrane is fluid - mosaic in nature, meaning it is flexible.
• The cell membrane controls what enters and exits a cell: This is true. It is a selectively permeable membrane.
• The cell membrane maintains a separate environment inside a cell: This is true. It separates the intracellular environment from the extracellular environment.

Answer:

The cell membrane controls what enters and exits a cell. The cell membrane maintains a separate environment inside a cell.