Question

An immobile element in plants is?
A) Calcium
B) Potassium
C) Phosphorus
D) Nitrogen

Answer 1

Hint: Immobile elements do not move meaning they are not transported in plants and get accumulated at absorbed sites. They do not participate in translocation.

Complete step by step answer:
-The micronutrients and macronutrients are essential for plant growth. The nitrogen (N), potassium (K) and phosphorus (P) are essential macronutrients which are needed in bulk amounts in the plant for growth. The micronutrients like manganese (Mn), boron (Bo), copper (Cu), etc. are essential but required in small amounts.
-The nutrients when absorbed are translocated throughout the plant body. The elements which move throughout the plant are called mobile elements. The nutrients which do not move throughout the plant are called immobile elements which stay accumulates in one place or move in very small distance.
-The examples of mobile elements are nitrogen (N), potassium (K) and phosphorus (P) and magnesium (Mg). They move from one place to another when there is any deficiency detected in plants. Even if there is deficiency like they are not absorbed at all, then the symptoms of deficiency are seen on older and lower leaves.
-The deficiency of immobile elements causes disease to plants. The examples of immobile elements are boron (Bo), copper (Cu), calcium (Ca), chlorine (Cl), cobalt (Co), iron (Fe), manganese (Mn), molybdenum (Mo), silicon (Si), sulfur (S) and zinc (Zn). The deficiency of such elements is first seen in younger leaves.

The correct option is A, calcium (Ca).

Note:
The immobile elements do not always show deficiency in some parts as they do not translocate. The mobile elements do not show deficiency in younger leaves because the nutrients are transported to the younger leaves and further deficiency is not observed.