Assertion. Calcium deficiency symptoms first appear in the apical region.
Reason. Calcium is highly mobile in plants

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

To analyze the assertion and reason provided in the question, we will break it down step by step.

### Step 1: Understanding the Assertion
The assertion states that "Calcium deficiency symptoms first appear in the apical region." This means that when a plant lacks calcium, the first visible signs of this deficiency will be seen in the growing tips or apical regions of the plant.

### Step 2: Understanding the Reason
The reason given is that "Calcium is highly mobile in plants." This implies that calcium can easily move within the plant tissues and can be transported to different parts of the plant as needed.

### Step 3: Evaluating the Assertion
Calcium is indeed essential for plant growth and development. It plays a critical role in maintaining cell wall structure and stability, and it is vital for cell division and elongation. When there is a deficiency of calcium, the apical meristem (the growing tip) is often the first area to show symptoms because it is actively dividing and requires a constant supply of calcium for proper growth.

### Step 4: Evaluating the Reason
While it is true that calcium is important for plants, it is not highly mobile. Unlike other nutrients such as nitrogen or potassium, calcium tends to remain in the tissues where it is deposited. This means that when there is a deficiency, the plant cannot easily redistribute calcium from older tissues to the new growth in the apical region.

### Step 5: Conclusion
Based on the evaluations:
- The assertion is true: Calcium deficiency symptoms do first appear in the apical region.
- The reason is false: Calcium is not highly mobile in plants.

Thus, the correct interpretation of the assertion and reason is that while both statements are true, the reason does not correctly explain the assertion.

### Final Answer
The correct answer is: Both A and R are true, but R is not the correct explanation of A.

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