Given below are two statements:

Statement I: Biomagnification occurs when the toxic burden of large number of organisms at higher trophic level is accumulated and concentrated in the organisms at lower trophic level

Statement II: The effect of toxins are magnified in the environment through food webs.

In the light of the above statements, choose the correct answer from the options given below

The correct answer is: Statement I is false but Statement II is true.

Let us carefully analyze each statement one by one to understand why this is the correct choice.

Analyzing Statement I:
Statement I says: "Biomagnification occurs when the toxic burden of large number of organisms at higher trophic level is accumulated and concentrated in the organisms at lower trophic level."

This statement is false because it has the direction of accumulation completely reversed. Biomagnification (also called biological magnification or bioamplification) is the process by which the concentration of toxic substances increases as you move up the food chain — that is, from lower trophic levels to higher trophic levels, not the other way around.

Here is how it actually works:

• Producers (plants, phytoplankton) — at the lowest trophic level — absorb small amounts of a toxin (e.g., DDT, mercury) from the environment.
• Primary consumers (herbivores) eat large quantities of producers, so they accumulate a higher concentration of the toxin in their bodies.
• Secondary consumers eat many primary consumers, accumulating an even higher concentration.
• Top predators (e.g., eagles, large fish, humans) — at the highest trophic level — end up with the greatest concentration of the toxin.

So the correct description of biomagnification is: toxic substances accumulate and concentrate in organisms at higher trophic levels, not lower ones. Because Statement I reverses this direction, it is false.

Analyzing Statement II:
Statement II says: "The effect of toxins are magnified in the environment through food webs."

This statement is true. This is the very essence of biomagnification. Toxins such as DDT, heavy metals (like mercury and lead), and persistent organic pollutants are not easily broken down or excreted by organisms. Instead, they get stored in fatty tissues. As energy and matter flow through the food web — from producers → primary consumers → secondary consumers → tertiary consumers — these toxins keep getting transferred and concentrated at each successive level.

The food web acts as a mechanism for amplifying the effect of toxins. Even if the initial concentration of a toxin in water or soil is very low, its effect becomes dramatically magnified by the time it reaches organisms at higher trophic levels. A classic example is DDT, which was found at concentrations millions of times higher in top predators like ospreys and bald eagles compared to the water they lived in, leading to reproductive failures in these birds.

Conclusion:
Statement I is false because it incorrectly states that toxins are concentrated in organisms at lower trophic levels — the actual process is the opposite.
Statement II is true because toxins genuinely are magnified through food webs, which is the defining feature of biomagnification.

Therefore, the correct answer is: Statement I is false but Statement II is true.