Calcium and sulphur.

Nitrogen.

They are angiosperms but follow saprophytic mode of nutrition. They absorb nutrients through mycorrhizal association.

Aluminium toxicity causes precipitation of nucleic acid, inhibition of ATPase, inhibition of cell division and binding of plasma membrane with Calmodulin.

Increase of mineral nutrients more than the normal concentration causes toxicity. A concentration, at which 10% of the dry weight of tissue is reduced, is considered as toxic.

Carbon, Hydrogen and Oxygen are called as skeletal elements and constitute about 94% of dry weight of plants. They play a important role in formation of organic compounds such as carbohydrates, fats and protein.

Yeast and Pullularia.

Biological chelating agents produced by bacteria are called siderophores. They are iron chelating agents which chelate Ferric iron from environment and host.

Fertilizers containing Nitrogen, Phosphate with Potassium in different proportions are called NPK fertilizers.

1. Potassium
2. Phosphorous
3. Sodium
4. Chlorine

Azotobacter is a non symbiotic Nitrogen fixing bacterium. When the bacterial culture is added to the soil, it multiplies and helps in fixation of nitrogen thereby increasing the fertility of the soil. Thus the growth and productivity of the maize crop will increase.

No Deficiency diseases occur due to deficiency of one or more minerals in a plant and affects only that plant. It cannot be transmitted from one plant to another. They are not caused by microbes.

(i) Mineral deficiency of plant A is due to Molybdenum
(ii) Mineral deficiency of plant B is due to Zinc

(i) Nitrogen fixation process requires Nitrogenase enzyme complex, Minerals (Mo, Fe and S), anaerobic condition, ATP, electron and glucose 6 phosphate as H⁺ donor.
(ii) Nitrogenase enzyme is active only in anaerobic condition.
(iii) To create this anaerobic condition a pigment known as leghaemoglobin is synthesized in the nodules which acts as oxygen scavenger and removes the oxygen.