Question

The main function of root hairs is to a. conduct water from cortex to aboveground shoots b. increase the root's surface area for absorption c. anchor the plant in soil

Short answer

The main function of root hairs is to increase the root's surface area for absorption (option b).

Step-by-step solution

Understanding the Question

We are asked to identify the main function of root hairs. The options provided suggest different aspects of plant root function, so focus is needed on distinguishing between water conduction, surface area for absorption, and anchoring.

Analyzing Each Option

Examine each option closely: - Option a discusses 'conduct water from cortex to aboveground shoots,' a function primarily associated with xylem tissue in plants, not root hairs. - Option b mentions 'increase the root's surface area for absorption,' which is a key role of root hairs to enhance the ability of roots to uptake water and nutrients. - Option c 'anchor the plant in soil,' although a function of the root system, does not directly specify root hairs' primary role.

Evaluating Root Hairs' Function

Root hairs are tiny extensions of root epidermal cells. Their small size and high number effectively increase the surface area available for absorption of water and minerals from the soil into the plant.

Choosing the Correct Answer

Given the evaluation, the main function of root hairs is to increase the root's surface area, facilitating the absorption of water and nutrients from the soil. Thus, option b is correct.

Key concepts

Plant Root Function

Roots are essential parts of a plant, performing several critical functions that ensure growth and survival. First and foremost, roots help anchor the plant securely in the soil, preventing it from being uprooted by wind or water. They act as the foundation of the plant structure.
Moreover, roots store nutrients and carbohydrates that the plant uses during periods of low photosynthesis or adverse conditions. This storage supports the plant's energy needs and helps in growth and development.
Additionally, roots serve as the main site for nutrient and water absorption. Through specialized structures like root hairs, roots can effectively gather water and essential minerals from the soil, providing nourishment to the entire plant system.

Water Absorption

Water absorption is a crucial process for plants to maintain their physiological functions and structural integrity. Root hairs play a pivotal role in this process. These are tiny extensions of root epidermal cells that greatly increase the root's surface area. The larger surface area allows root hairs to efficiently absorb water from the surrounding soil particles.
Water absorption begins at the root surface, where water moves into the plant through osmosis. Root hairs act as a bridge, facilitating the absorption and movement of water from the soil into the root system and ultimately throughout the plant.
This absorbed water is vital for various plant functions, including photosynthesis, nutrient transport, and maintaining turgor pressure, which prevents plants from wilting.

Nutrient Uptake

Nutrient uptake is another fundamental role of root hairs, and it works hand in hand with water absorption. Nutrients, such as nitrogen, phosphorus, and potassium, are dissolved in the soil water and must be absorbed by plants to support growth.
Root hairs capture these dissolved nutrients as they absorb water. The increased surface area provided by root hairs enables plants to access more nutrients than they could without these specialized extensions. This efficiency is crucial, especially in environments where nutrient availability is limited.
Besides the primary nutrients, root hairs also help absorb trace elements and minerals necessary for plant health and development. These include essential micronutrients like zinc, iron, and manganese. All these nutrients contribute to various plant functions, including enzyme activation, chlorophyll production, and overall cellular function, ensuring a healthy and thriving plant.