Question

In plants chlorosis is caused by the deficiency of
(a)Nitrogen
(b)Manganese
(c)Magnesium
(d)All the above

Answer 1

Hint: All plants require certain elements to stay them healthy. Those elements they need in relatively large amounts, including nitrogen and magnesium, are referred to as macronutrients. Those they need in very small amounts, like copper and zinc, are mentioned as micronutrients, or trace elements.

Complete answer:
Chlorosis is a condition of loss of the normal green colouration of leaves of plants due to insufficient chlorophyll for photosynthesis. The shortage of iron is one among the more common nutrients related to chlorosis. Manganese or zinc or magnesium deficiencies within the plant also will cause chlorosis. Deficient nitrogen or proteins can also cause chlorosis. Hence in plants, chlorosis is caused by the deficiency of nitrogen, manganese, magnesium.

Additional Information:
Chlorosis is a condition in plants where the leaves have yellowish colouration because of insufficient chlorophyll in their cells. Chlorosis is often caused by a variety of reasons including; deficiency of nutrients (such as iron, nitrogen, manganese, zinc), disease infestation, damaged roots, high soil alkalinity and compacted roots. It results from failure of chlorophyll to develop due to infection by a virus; lack of an important mineral or oxygen; injury from alkali, fertilizer, pollution, or cold; insect, mite, or nematode feeding; gas main leaks; compaction or change in soil level; and stem or plant disease. Severely chlorotic plants are stunted, and shoots may die down to the roots. Control is aimed specifically at the cause of the disease.

So, the correct answer is, “all the above.”

Note: Nutrient deficiency symptoms could also be classified as follows:
-A complete failure at the seedling stage.
-Severe stunting of plants.
-Internal abnormalities like clogged conductive tissues.
-Delayed or abnormal maturity.
-Observing yield differences, with or without leaf symptoms.
-Poor quality of crops, including the other problems like differences in protein, oil, or starch content, and the storage quality.
-Yield differences detected only by careful experimental work.