The correct option is 1, 2, 3 and 4
Explanation
Essential elements for plant growth are classified into two broad categories based on the quantitative requirements of the plant: Macronutrients and Micronutrients.
- Macronutrients: These are generally present in plant tissues in large amounts (in excess of 10 mmole kg-1 of dry matter).
- Micronutrients: These are needed in very small amounts (less than 10 mmole kg-1 of dry matter).
Statement-wise Analysis:
- Pair 1 is Correct: Nitrogen (N), Phosphorus (P), and Potassium (K) are classified as Macronutrients. Specifically, they are often termed "Primary Macronutrients" because they are required in the largest quantities for plant growth and metabolism.
- Pair 2 is Correct: Iron (Fe), Manganese (Mn), and Zinc (Zn) are classified as Micronutrients. They act as cofactors for various enzymes and are essential for physiological processes despite being required in trace amounts.
- Pair 3 is Correct: Calcium (Ca), Magnesium (Mg), and Sulphur (S) are classified as Macronutrients. They are often referred to as "Secondary Macronutrients" but fall under the broad category of macronutrients due to the quantity required.
- Pair 4 is Correct: Copper (Cu), Molybdenum (Mo), and Chlorine (Cl) are classified as Micronutrients. They are essential trace elements required for specific metabolic functions such as electron transport and enzyme activation.
Key Takeaway:
The essential Macronutrients are Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, and Sulphur. The essential Micronutrients are Iron, Manganese, Copper, Molybdenum, Zinc, Boron, Chlorine, and Nickel.