Mineral Nutrition Test - 6

Zinc is a micronutrient or trace element present in plant body in concentration less than or equal to 0.1 mg per gm of dry matter.

Magnesium is available in the soil as divalent Mg⁺² ion. Magnesium is required in critical reactions of respiration, DNA and RNA synthesis, fat synthesis and carbohydrate metabolism. It is also an activator of critical enzymes like RuBP carboxylase and PEP carboxylase.

Chlorine is required in plants for cell division and is also an important solute for developing osmotic potential. Due to the deficiency of chlorine, there is wilting of leaves followed by chlorosis and necrosis and the leaves ultimately become bronzed.

Calcium acts as second messenger for hormonal and environmental responses in plant and thus becomes associated with cytosol protein, calmodulin.

Nitrification is the second step in nitrogen cycle. In this step, ammonium is converted into nitrate with the help of microorganisms called nitrite microorganism,e.g. Nitrosomonas, Nitrosococcus, Aspergillus etc.

This statement is correct as azollapinnata contains symbiotic nitrogen fixing blue green algae Anabaena azollae in its fronds,that helps in nitrogen fixation.

Irregular patches of different colours like appearence of dark green colour, anthocyanin pigmentation, loss of chlorophyll from leaves due to Phosphorus and Molybdenum deficiency is called mottling.

It is a disease caused due to the deficiency of molybdenum in which the lamina of the leaf degenerates but petiole and midrib persist.

The elements which synthesise cellulose and other components of the cell walls are called framework elements. The three non mineral elements I.e. carbon, hydrogen and oxygen function as framework elements. Calcium is also a component of middle lamella.

The elements that get absorbed by plants and reduce their growth and yield are called toxic elements. Examples are Lead, Aluminum.