Final answer:
Root hairs generally have a thin or absent cuticle to facilitate the absorption of water and minerals, unlike the thicker cuticle on the stems and leaves which serves to reduce water loss and control gas exchange.
Step-by-step explanation:
The cuticle of plant aerial parts such as stems and leaves is a waxy, waterproof layer that reduces water loss and helps in controlling gas exchange.
This cuticle is generally thicker and helps in the prevention of water loss through transpiration.
However, root hairs have a very thin or non-existent cuticle since their main function is the absorption of water and minerals.
The lack of a significant cuticle in root hairs allows for easier entry of water and nutrients necessary for the plant's growth.
These root hairs extend from the epidermis of the root, which is surrounded by ground tissue and vascular tissue, helping to increase the root's surface area and thus its absorption capabilities.