Water is essential for all physiological activities of the plant and plays a very important role in all living organisms.

Answer

**Step-by-Step Solution:**

1. **Understanding the Importance of Water in Plants:**
- Water is crucial for various physiological processes in plants. It acts as a solvent for nutrients, enabling their transport throughout the plant.

2. **Role of Water in Maintaining Turgidity:**
- Water helps maintain turgidity in plant cells, which is essential for structural support. Turgid cells keep the plant upright and firm.

3. **Water Composition in Living Organisms:**
- Approximately 90% of the plant body is composed of water, while around 75% of the human body is made up of water. This highlights the significance of water in living organisms.

4. **Water in Photosynthesis:**
- Water is a key reactant in the process of photosynthesis, where it is used to produce glucose and oxygen. This process is vital for plant growth and energy production.

5. **Oxygen Production and Respiration:**
- During photosynthesis, plants release oxygen as a byproduct, which is essential for respiration in animals and humans. This underscores the interconnectedness of water, plants, and all living organisms.

6. **Conclusion:**
- Given the critical roles that water plays in physiological activities, maintaining cell structure, and supporting life processes, the statement that "water is essential for all physiological activities of the plant and plays a very important role in all living organisms" is true.

**Final Answer:**
- The statement is **True**.

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