Tissue commonly known as passport point or biological check post is characterised by

Options

A. Bulliform cells and raphides
B. Cystolith and motor cells
C. Casparian bands and passage cells
D. Passage cells and starch

Answer

### Step-by-Step Solution:

1. **Identify the Question**: The question asks about the tissue commonly referred to as the "passport point" or "biological check post."

2. **Understand the Options**: The options provided are:
- Buliform cells and raphides
- Systoleth and motor cells
- Casparian bands and passage cells
- Passage cells and starch

3. **Analyze the Key Terms**:
- The term "passport point" or "biological check post" suggests a function related to selective permeability or regulation of substances.

4. **Focus on the Correct Answer**:
- The correct answer is **Casparian bands and passage cells**.

5. **Explain Casparian Bands**:
- Casparian bands are found in the endodermis of roots. They are waterproof structures that prevent water and solutes from entering the pericycle, thereby controlling the movement of substances into the vascular system of the plant.

6. **Explain Passage Cells**:
- Passage cells are specialized cells in the endodermis that provide areas of low resistance for the movement of water and nutrients. They facilitate the selective uptake of solutes.

7. **Conclusion**:
- Together, the Casparian bands and passage cells regulate the movement of water and nutrients, acting as a "passport point" or "biological check post" in plant tissues.

### Final Answer:
The tissue commonly known as the "passport point" or "biological check post" is characterized by **Casparian bands and passage cells**.

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