a) Define stomatal frequency & stomatal index. Describe the main functions performed by stomata.

Stomatal frequency: Stomatal frequency is the number of stomata per unit area.

Stomatal index: Stomatal index is the ratio of a number of stomata to the total number of cells per unit area.

b) A chart of Macronutrients & Micronutrients with their function

MACRONUTRIENTS
Nitrogen (N) - Nitrogen is necessary for plant growth.
Phosphorus (P) - Phosphorus is involved in phosphorylation reactions.
Potassium (K) - Potassium maintains tugidity of cells.
Sulphur (S) - Sulphur helps in chlorophyll formation.
Calcium (Ca) - Calcium is utilized for continuous cell division & formation.
Magnesium (Mg) - Magnesium acts as a key element of chlorophil production.

MICRONUTRIENTS
Iron (Fe) - Iron acts as a electron transporter in photosynthesis & respiration.
Manganese (Mn) - Manganese helps in metabolism & photolytic evolution of oxygen.
Zinc (Zn) - Zinc is actively involved in the Nitrogen metabolism of the plant.
Copper (Cu) - The important function of copper in plant is electron transfer. (Cu^2+ + e^- -> Cu^+)
Molybdenum (Mo) - The most important function of Mo in plant metabolism is in N assimilation.
Boron (B) - Boron acts as an oxygen carrier.
Chlorine (Cl) - Chlorine is necessary for an important reaction in photosynthesis.
Silicon (Si) - Silicon promotes the formation af reproductive argan in plant (Rice).
Cobalt (Co) - Co is essential for symbiotic N2 fixation.