Which of the following elements is a macronutrient for higher plants and micronutrient for algae?

Options

A. Ca
B. Co
C. Cu
D. Cd

Answer

To solve the question regarding which element is a macronutrient for higher plants and a micronutrient for algae, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Macronutrients and Micronutrients**:
- Macronutrients are essential elements that plants require in large amounts for their growth and development. Examples include Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur, Potassium, Calcium, and Magnesium.
- Micronutrients are elements that are required in smaller amounts. Examples include Iron, Copper, Molybdenum, Zinc, Boron, Chlorine, and Nickel.

2. **Analyze the Given Options**:
- The elements provided are Calcium, Cobalt, Copper, and Cadmium.
- We need to determine which of these is a macronutrient for higher plants and a micronutrient for algae.

3. **Identify the Role of Each Element**:
- **Calcium**: Known to be a macronutrient for higher plants. It is crucial for cell wall synthesis, cell division, and normal metabolic activities.
- **Cobalt**: Not typically classified as an essential nutrient for plants or algae.
- **Copper**: Classified as a micronutrient for both plants and algae.
- **Cadmium**: Generally considered toxic and not an essential nutrient for either group.

4. **Conclusion**:
- Based on the classifications, Calcium is the element that serves as a macronutrient for higher plants and is not recognized as a significant nutrient for algae. Therefore, it is the correct answer.

### Final Answer:
**Calcium** is the element that is a macronutrient for higher plants and a micronutrient for algae.

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