What are macro-nutrients and why are they called macro- nutrients ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Macronutrients**: Macronutrients are nutrients that are required by organisms in large quantities. They are essential for various physiological functions and processes within the organism.

2. **List of Macronutrients**: In the context of plants, there are six primary macronutrients:
- Nitrogen (N)
- Phosphorus (P)
- Potassium (K)
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