Which of the following statements about cell junctions are correct ?
(i) All the cells of the epithelium are held together with little intercellular materials
(ii) In almost all animal tissues specialised junctions provide both structural and functional link between their individual cells
(iii) Tight junctions prevent substances from leaking across a tissue
(iv) Adhering junctions provide cementing to keep neighbouring cells together
(v) Gap junction provide cytoplasmic channels between cells for passage of ions, small molecules and sometimes big molecules.

Options

A. (ii) and (iii)
B. (i),(ii) and (iii)
C. (iv) and (v)
D. (i),(ii),(iii),(iv) and (v)

Answer

To determine which statements about cell junctions are correct, let's analyze each statement one by one based on what we know about cell junctions in animal tissues.

### Step-by-Step Solution:

1. **Statement (i): All the cells of the epithelium are held together with little intercellular materials.**
- **Analysis:** This statement is true. Epithelial cells are tightly packed with minimal intercellular space, which is characteristic of epithelial tissue. The cells are connected through various types of junctions, allowing them to function as a cohesive unit.

2. **Statement (ii): In almost all animal tissues, specialized junctions provide both structural and functional link between their individual cells.**
- **Analysis:** This statement is also true. Specialized junctions like tight junctions, adhering junctions, and gap junctions play crucial roles in maintaining the integrity and function of tissues by linking cells structurally and functionally.

3. **Statement (iii): Tight junctions prevent substances from leaking across a tissue.**
- **Analysis:** This statement is true. Tight junctions create a barrier that prevents the passage of materials between cells, thereby controlling the movement of substances across epithelial layers.

4. **Statement (iv): Adhering junctions provide cementing to keep neighboring cells together.**
- **Analysis:** This statement is true. Adhering junctions, also known as desmosomes, help to anchor cells together, providing mechanical stability and strength to tissues.

5. **Statement (v): Gap junctions provide cytoplasmic channels between cells for the passage of ions, small molecules, and sometimes big molecules.**
- **Analysis:** This statement is true. Gap junctions form channels that allow for direct communication between adjacent cells, facilitating the transfer of ions and small signaling molecules.

### Conclusion:
All five statements about cell junctions are correct. Therefore, the answer is that statements (i), (ii), (iii), (iv), and (v) are all true.

### Final Answer:
All statements (i), (ii), (iii), (iv), and (v) are correct.

---