Final answer:
Root hairs aid in absorption by increasing the root's surface area, improving contact with the soil, and engaging in active transport for nutrients. The epidermis also assists in this process by protecting the root and facilitating absorption.
Step-by-step explanation:
The root hairs of a plant are primarily responsible for the absorption of water and minerals from the soil. These root hairs are extensions of root epidermal cells and serve to significantly increase the surface area of the root.
This increment in surface area is beneficial for uptake because it increases the volume of soil that the root can contact, and enhances the efficiency of water and nutrient absorption.
Moreover, root hairs, being very close to the soil particles, minimize the occurrence of air gaps that could impede absorption. They also partake in metabolic functions like active transport, which is crucial for mineral uptake. In addition to passive absorption, minerals, and nutrients are actively transported into the root hairs using energy in the form of ATP.
Furthermore, the epidermis of the root not only offers protection but also aids in the absorption process. Considering water availability, when soil is very moist, water can also move through the soil directly to the roots, bypassing the root hairs.
However, in many cases, root hairs enhance the plant's ability to take up the necessary nutrients and fluids from the surrounding soil, despite the water movement in the soil.