Question

If deficiency syndrome of elements ‘A’ appears first in older tissues and of elements ‘B’ appear first in younger tissues, then choose the correct one from the following regarding these elements.
A. A = Nitrogen; B = Magnesium
B. A = Calcium; B = Sulphur
C. A = Sulphur; B = Potassium
D. A = Magnesium; B = Calcium

Answer 1

Hint: The plants absorb nutrients from soil by the roots. Some minerals are called macronutrients and some are called micronutrients. Nitrogen, Sulphur, Phosphorus, Calcium, Magnesium, etc are the macronutrients, and Iron, Manganese, copper, Zinc, etc are considered as micronutrients.

Complete answer: The deficiency symptoms of some minerals are first seen in older leaves or tissues of a plant – these mineral elements are called mobile elements.
For example – nitrogen, potassium, phosphorus, zinc, molybdenum, nickel, magnesium, etc.
Again deficiencies of some of these nutrients show earlier effects and some show delayed effects on plants.
The deficiency symptoms of some minerals are first seen in younger leaves or tissues of a plant – these mineral elements are called immobile elements.
For example – calcium, sulphur, iron, copper, boron, etc.
For this question, A can be nitrogen or magnesium and B can be sulphur or calcium.

Hence, the correct answer is option D. A=Magnesium and B=Calcium.

Note: Some basic functions of nutrient minerals are:
1. Boron is important in sugar transport, cell division, and amino acid production.
2. Copper is a major component of enzymes and plays a key role in photosynthesis.
3. Iron is essential for chlorophyll synthesis and plays a major role in photosynthesis.
4. Molybdenum is involved in nitrogen metabolism and nitrogen fixation.
5. Zinc helps in auxin activity.
6. Chlorine is used in turgor regulation.
7. Magnesium helps in metabolism and chlorophyll synthesis.