Compare the three types of epidermis cells – guard cells, pavement cells and root hair cells.

Guard Cells: These are specialized cells in the epidermis of leaves, stems and other organs that are used to control gas exchange. They are produced in pairs with a gap between them that forms a stomatal pore. The function of guard cells is to control the opening and closing of stomata, thus regulating the process of transpiration and gas exchange.

Pavement Cells: Also known as parenchyma cells, these are the most common type of epidermal cells. They are irregularly shaped, fitting together like pieces of a jigsaw puzzle. Their main function is to provide protection and control the loss of water. They are also involved in the secretion of metabolic compounds and the absorption of water and mineral nutrients.

Root Hair Cells: These are specialized cells located in the roots of plants. They are tubular extensions of epidermal cells and are involved in the absorption of water and nutrients from the soil. They have a large surface area to maximize absorption.

In summary, while all three types of cells are part of the plant's epidermis, they each have different functions. Guard cells control gas exchange and transpiration, pavement cells provide protection and control water loss, and root hair cells absorb water and nutrients from the soil.