* Semipermeable membrane: This means that the membrane allows certain substances to pass through while blocking others. This selective permeability is crucial for the cell to maintain its internal environment and function properly.

Here's why both animal and plant cells need semipermeable membranes:

* Regulation of nutrient uptake: Cells need to take in nutrients like glucose, amino acids, and water. The membrane allows these essential substances to pass through while preventing harmful molecules from entering.

* Waste removal: Cells produce waste products as a result of metabolic processes. The membrane helps in expelling these waste products from the cell.

* Maintaining internal environment: The membrane controls the movement of ions and water, ensuring a stable internal environment (homeostasis) for the cell to function optimally.

While both animal and plant cells have semipermeable membranes, there are some differences:

* Plant cells have an additional cell wall: This rigid structure provides support and protection, and also acts as a filter, controlling what enters and exits the cell.

* Plant cells have a larger central vacuole: This vacuole stores water and other substances, which contributes to maintaining the cell's turgor pressure and shape.

Overall, both animal and plant cells rely on semipermeable membranes to regulate their internal environment and maintain their function.