Question

The length of root hair is

• A. 1-10 mm
• B. 11-20 mm
• C. 21-30 mm
• D. 31-40 mm

Hint:

{Interesting fact:} Even though each root hair is only a few millimeters long, a single plant may possess {millions of root hairs}. Together, they create a very large surface area that greatly improves the plant's ability to absorb water and minerals from the soil.

Answer 1

The Correct Option is A

Concept:
Root hairs are thin, tubular extensions of the epiblema (epidermal cells) of young roots. They are unicellular structures that greatly increase the surface area available for the absorption of water and mineral nutrients from the soil. Root hairs play a crucial role in plant nutrition because they come in direct contact with soil particles and absorb water through the process of osmosis, while mineral ions are absorbed through both passive and active transport mechanisms.
Step 1: Location of root hairs.
Root hairs are present in the zone of maturation (zone of differentiation) of the root. This region lies just behind the zone of elongation and is specialized for absorption.
Step 2: Characteristics of root hairs.
Root hairs possess several important features:

• They are unicellular outgrowths of epidermal cells.
• They are very delicate and short-lived.
• As the root grows, old root hairs are continuously replaced by new ones.
• They grow between soil particles to absorb capillary water and dissolved minerals.

Step 3: Determining the typical length of root hairs.
Although root hairs are microscopic structures, their length is relatively larger compared to other epidermal cell projections. The typical length of a root hair generally ranges between: \[ 1 -- 10 mm \] This length helps them penetrate small spaces between soil particles and effectively absorb water and nutrients. Final Answer: \(\boxed{1 \text{--} 10 \text{ mm}}\)