Which of the following statements is false ?

Options

A. `Ca^(2+)` ions are not important in maintaining the regular beating of the heart.
B. `Mg^(2+)` ions are ions are important in the green parts of the plants .
C. `Mg^(2+)` ions form a complex with ATP.
D. `Ca^(+)` ions are important in blood clotting

Answer

To determine which statement is false among the options provided, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze the First Statement**:
- Statement: "Ca²⁺ ions are not important in maintaining the regular beating of the heart."
- Explanation: Calcium ions (Ca²⁺) play a crucial role in the contraction of heart muscles. They are essential for the heart to beat regularly and pump blood effectively. Therefore, this statement is false.

2. **Analyze the Second Statement**:
- Statement: "Mg²⁺ ions are important in the green parts of the plant."
- Explanation: Magnesium ions (Mg²⁺) are indeed vital as they are the central atom in chlorophyll, which is responsible for the green color in plants and is essential for photosynthesis. This statement is true.

3. **Analyze the Third Statement**:
- Statement: "Mg²⁺ ions form a complex with ATP."
- Explanation: Magnesium ions bind with ATP (adenosine triphosphate) to form a complex that is necessary for ATP to be biologically active. This statement is also true.

4. **Analyze the Fourth Statement**:
- Statement: "Ca²⁺ ions are important in blood clotting."
- Explanation: Calcium ions (Ca²⁺) are indeed crucial for the blood clotting process. They play a significant role in the coagulation cascade. This statement is true.

### Conclusion:
After analyzing all the statements, we find that the first statement is false. Therefore, the answer is:

**The false statement is: "Ca²⁺ ions are not important in maintaining the regular beating of the heart."**

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