Egg membrane used to demonstrate osmosis through thistle funnel experiment acts as

Options

A. Selectively permeable
B. Differentially permeable
C. Permeable
D. Semipermeable

Answer

To answer the question about the role of the egg membrane in the thistle funnel experiment, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Thistle Funnel Experiment**:
- The thistle funnel experiment is designed to demonstrate the process of osmosis, which is the movement of water across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

2. **Identifying the Role of the Egg Membrane**:
- In this experiment, the egg membrane is used to simulate a biological membrane. It is crucial to understand the properties of this membrane to determine its function in osmosis.

3. **Defining Membrane Types**:
- There are different types of membranes based on their permeability:
- **Permeable**: Allows all substances to pass through.
- **Impermeable**: Does not allow any substances to pass through.
- **Selectively Permeable**: Allows certain substances to pass while blocking others based on size or charge.
- **Semi-permeable**: Similar to selectively permeable, it allows the passage of small molecules (like water) while preventing larger molecules (like solutes) from passing through.

4. **Conclusion**:
- The egg membrane acts as a semi-permeable membrane because it allows water to pass through but restricts the movement of larger solute particles. This property is essential for demonstrating osmosis in the experiment.

5. **Final Answer**:
- Therefore, the correct option is **option number four: semi-permeable**.