Final answer:
The root hair represents the cellular level of organization in plants, allowing roots to efficiently obtain water and minerals from the soil.
Step-by-step explanation:
The root hair represents the cellular level of organization in plants. Root hairs are extensions of root epidermal cells, which increase the surface area of the root and greatly contribute to the absorption of water and minerals from the soil. They are specialized structures that allow roots to efficiently obtain necessary resources for the plant's growth and development.