Which of the following organelles is bound by the tonoplast?

Options

A. Golgi complex
B. Endoplasmic retuculum
C. Vaculoes
D. Lysosmes

Answer

To determine which organelle is bound by the tonoplast, we will analyze the options provided step by step.

### Step 1: Understand what tonoplast is
- **Definition**: Tonoplast is a single membrane that surrounds the vacuole in plant cells. It acts as a protective barrier and regulates the movement of substances in and out of the vacuole.

**Hint**: Remember that tonoplast is specific to plant cells and is not found in animal cells.

### Step 2: Analyze the options
1. **Golgi complex**:
- The Golgi complex is a double membrane structure responsible for modifying, sorting, and packaging proteins. It does not have tonoplast.

**Hint**: Double membrane structures do not use tonoplast.

2. **Endoplasmic reticulum (ER)**:
- The ER is also a double membrane structure involved in protein and lipid synthesis. Like the Golgi complex, it does not have tonoplast.

**Hint**: Again, focus on the membrane structure; tonoplast is not involved here.

3. **Vacuole**:
- Vacuoles are large membrane-bound sacs within plant cells that store substances such as water, ions, and nutrients. The tonoplast surrounds the vacuole, making it the correct answer.

**Hint**: Vacuoles are specifically associated with tonoplast in plant cells.

4. **Lysosome**:
- Lysosomes are membrane-bound organelles that contain enzymes for digestion. They do not have tonoplast.

**Hint**: Lysosomes are found in both plant and animal cells but do not have tonoplast.

### Step 3: Conclusion
- Based on the analysis, the only organelle that is bound by the tonoplast is the **vacuole**.

**Final Answer**: Vacuole