Question

Identify the method by which plants are used to clean up contamination.

• A. Bio remediation
• B. Phytoremediation
• C. Biomagnification
• D. Bioaccumulation

Hint:

Phyto = plant: Phytoremediation uses plants to clean polluted environments. Bio = life: Bioremediation uses microbes (bacteria/fungi) for the same purpose. Do not confuse with Biomagnification (toxins increasing up the food chain) or Bioaccumulation (toxins building up within an organism) --- these describe problems, not solutions.

Answer 1

The Correct Option is B

Concept:
Environmental contamination by heavy metals, pesticides, organic pollutants, and other toxic substances is a major problem. Several biological techniques are used to clean up contaminated soil and water. The specific use of

plants for this purpose is a distinct and well-defined approach.

Step 1: Define Phytoremediation.

Phytoremediation (from the Greek phyto = plant, and Latin remedium = restoring balance) is the use of

living plants and their associated microorganisms to clean up contaminated environments --- soil, water, or air. Mechanisms of phytoremediation:

• Phytoextraction (phytoaccumulation): Plants absorb contaminants (especially heavy metals like lead, cadmium, arsenic) through their roots and accumulate them in shoots/leaves, which are then harvested and removed.

• Phytodegradation: Plants and their root-associated microbes break down organic pollutants (pesticides, solvents).

• Rhizofiltration: Plant roots absorb and adsorb contaminants from water.

• Phytostabilization: Plants immobilize contaminants in the soil, reducing their mobility and bioavailability.

• Phytovolatilization: Plants take up contaminants and release them as vapors through transpiration (e.g., mercury, selenium).
Example plants used: Thlaspi caerulescens (hyperaccumulator of zinc/cadmium), sunflower (Chernobyl cleanup), vetiver grass, Indian mustard.

Step 2: Distinguish from the other options.

• (A) Bioremediation: Uses

microorganisms (bacteria, fungi) to degrade or detoxify contaminants. This is a broader term --- phytoremediation is a subset of bioremediation. The question specifically asks about plants, which points to phytoremediation.

• (C) Biomagnification (bioamplification): This is the

increase in concentration of a toxic substance (like DDT) as it moves up the food chain. It is the problem, not the solution.

• (D) Bioaccumulation: The process by which an organism accumulates toxic substances in its body tissues (concentration in one organism). It is also related to the problem, not the cleanup.