Karthikeyan

Epidermis

• The epidermis is the outermost layer of cells covering the leaves, stems, and roots of a plant.

• It protects the plant from water loss, injury, and infection.

• Cells are closely packed and often covered with a waxy cuticle to reduce evaporation.

• In leaves, it contains stomata, which control gas exchange and transpiration.

Key Points:

Price Elasticity of Demand (PED)

Meaning: Price elasticity of demand shows how much the demand for a product changes when its price changes. It helps us understand how sensitive customers are to price changes.

For example:

• If the price of ice cream goes up and people stop buying it quickly, the demand is elastic.

• But if the price of salt goes up and people still buy it, the demand is inelastic.

Formula: