Which cell junction help to stop substances from leaking across a tissue ?

Options

A. Gap junction
B. Tight junction
C. Desmosomes
D. All of these

Answer

**Step-by-Step Text Solution:**

1. **Understanding Cell Junctions**: Cell junctions are specialized structures that connect two cells together. They play various roles in maintaining the integrity of tissues and facilitating communication between cells.

2. **Identifying the Options**: The question provides four options:
- A) Gap junction
- B) Tight junction
- C) Desmosomes
- D) All of the above

3. **Analyzing Each Option**:
- **Gap Junction**: This type of junction allows for the passage of ions and small molecules between adjacent cells, facilitating communication. However, it does not prevent leakage of substances across tissues.
- **Tight Junction**: This junction forms a barrier that prevents substances from leaking between cells. It is located at the periphery of cells and tightly seals the space between them, thereby controlling the passage of materials.
- **Desmosomes**: These junctions provide mechanical strength by anchoring cells together but do not prevent leakage of substances.
- **All of the Above**: This option suggests that all types of junctions prevent leakage, which is incorrect.

4. **Conclusion**: Based on the analysis, the only cell junction that effectively stops substances from leaking across a tissue is the **Tight Junction**.

5. **Final Answer**: The correct answer is **B) Tight Junction**.

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