Concept: This question tests your basic knowledge of plant morphology, specifically the structure protecting the growing tip of a root.

Why (A) is correct: The root apex (the tip of the root) is covered by a protective, thimble-like structure called the root cap. This cap protects the delicate meristematic cells of the root tip as it pushes through the soil.

Why other options are wrong:

• (B) stem, cuticle: The stem is covered by a cuticle, but the cuticle is a waxy layer, not a thimble-like structure at the apex.
• (C) root, root hair: Root hairs are epidermal outgrowths involved in absorption, located behind the root cap, not covering the apex.
• (D) stem, tendrils: Tendrils are modified stems or leaves for climbing, not a protective covering at the stem's apex.

Common Mistake: Students sometimes confuse root hairs with the root cap or think the root cap is involved in absorption.

NEET Tip: Remember that the root cap is unique to roots and its primary function is protection. Stems have apical meristems protected by young leaves, not a cap.

Correct Answer: (A)