Correct Option: B. Epidermis of root Detailed Explanation: Root hairs are specialized structures that emerge from the epidermis of the root. They play a crucial role in the absorption of water and nutrients from the soil. Let’s break down the reasoning behind this answer:

1. Understanding Root Structure:
2. The root is composed of several layers, including the outermost layer known as the epidermis, which serves as a protective barrier and is involved in the absorption of water and minerals.
3. Beneath the epidermis, there are other layers such as the cortex, endodermis, and vascular bundles (which include xylem and phloem).
4. Development of Root Hairs:
5. Root hairs are extensions of the epidermal cells. They are not separate structures but rather outgrowths that increase the surface area of the root, enhancing its ability to absorb water and nutrients.
6. These hairs typically develop in regions of the root that are actively growing, particularly in the zone of maturation, where the root has already penetrated the soil.
7. Function of Root Hairs:
8. The primary function of root hairs is to facilitate the uptake of water and dissolved minerals from the soil. Their large surface area allows for more efficient absorption.
9. Root hairs also help anchor the plant in the soil, providing stability.

Why Other Options Are Incorrect:

• A. Root Apex:
• The root apex is the tip of the root where growth occurs. While it is crucial for root development, root hairs do not originate from this region. Instead, they form from the epidermis further up the root where the cells have differentiated.
• C. Vascular Bundles:
• Vascular bundles are responsible for the transport of water, nutrients, and food within the plant. They consist of xylem and phloem tissues. Root hairs do not develop from these bundles; rather, they are found in the epidermis, which is separate from the vascular tissues.
• D. Endodermis:
• The endodermis is a layer of cells that regulates the flow of water and nutrients into the vascular system of the root. It is located inside the cortex and does not give rise to root hairs. Root hairs are specifically derived from the outermost layer, the epidermis.

Summary of Key Points:

• Root hairs are extensions of the epidermal cells of the root, enhancing water and nutrient absorption.
• They develop in the zone of maturation, not at the root apex or from vascular bundles or endodermis.
• The epidermis serves as the primary site for root hair formation, making option B the correct answer.

Revision Summary:

• Root hairs originate from the epidermis of the root.
• They increase the surface area for absorption of water and nutrients.
• Root hairs are not formed from the root apex, vascular bundles, or endodermis.
• Understanding root structure is essential for grasping the function of root hairs in plant biology.