Question

Identify the elements whose deficiency causes both necrosis and chlorosis?
A. Cu and Co
B. Mo and Ca
C. Mg and K
D. Fe and Mn

Answer 1

Hint: The plant requires some elements for the growth and developmental processes. The deficiency of these elements causes adverse effects on the growth of the plant. The deficiency of the elements like Mg and K results in necrosis and chlorosis. Necrosis means the death of the living tissue and chlorosis means decolorization of the pigment of the leaves.

Complete answer:
Option A- Cu and Co
Co is the element cobalt (atomic number: 27) and cu is copper (atomic number: 29) in the periodic table.

Option B- Mo and Ca
Mo is Molybdenum which is a chemical element with atomic number 42. It is classified as a transition metal and is solid in the room. Ca stands for Calcium. A chemical element with atomic number 20. It is classified as alkaline.

Option C- Mg and K
K is potassium and mg is magnesium. The balance of Potassium and magnesium can frequently get altered by common pathological conditions. Their deficiency leads to necrosis and chlorosis.

Option D- Fe and Mn
Fe is a chemical element with atomic number 26. And Manganese (Mn), is a chemical element which is one of the silvery-white, hard, brittle metals of Group 7 (VIIb) of the periodic table.

Thus, the correct answer is option C- Mg and K.

Note: Deficiencies of certain nutrients like nitrogen, phosphorus, potassium, and magnesium result in chlorosis (yellowing) and eventual necrosis (death) of older mature leaves. The symptoms shown here can also occur naturally as the top-growth outgrows the root system, or when competition occurs between plants for soil nutrients.