How does the cell wall of a plant cell compare to the plasma membrane of an animal cell?

• A. The cell wall allows free passage of all molecules, while the plasma membrane is impermeable to all substances.
• B. The plasma membrane is only found in plant cells, whereas the cell wall is unique to animal cells.
• C. Both the cell wall and the plasma membrane are composed mainly of phospholipids and serve identical functions in all cells.
• D. The cell wall is a rigid structure made primarily of cellulose, providing structural support, while the plasma membrane is a flexible, phospholipid bilayer that regulates the movement of substances in and out of the cell.

Answer: (D)

Verified step by step guidance

1. Understand the structural differences: The cell wall is a rigid structure found in plant cells, composed mainly of cellulose, which provides structural support and protection. The plasma membrane, on the other hand, is a flexible phospholipid bilayer found in both plant and animal cells, responsible for regulating the movement of substances in and out of the cell.
2. Recognize the functional differences: The cell wall allows free passage of certain molecules due to its porous nature, but it does not regulate molecular movement actively. The plasma membrane actively regulates the movement of substances through mechanisms like diffusion, osmosis, and active transport.
3. Identify the composition: The cell wall is primarily made of cellulose, a carbohydrate polymer, while the plasma membrane is composed of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates.
4. Clarify the presence in cell types: The cell wall is unique to plant cells (and some fungi and bacteria), whereas the plasma membrane is present in all cell types, including both plant and animal cells.
5. Summarize the key distinction: The cell wall provides structural support and protection, while the plasma membrane is involved in selective permeability and communication between the cell and its environment.