If a water body is contaminated with toxicant , its biomagnification will be more marked in

Options

A. water
B. planktons
C. small fishes
D. birds

Answer

To solve the question regarding which organism will experience the most marked biomagnification in a contaminated water body, we can break it down into the following steps:

### Step 1: Understand Biomagnification
Biomagnification refers to the increasing concentration of toxic substances in the tissues of organisms at each successive level of the food chain. As you move up the trophic levels, the concentration of toxins increases.

**Hint:** Think about how toxins accumulate as they move through different levels of the food chain.

### Step 2: Identify Trophic Levels
In a typical aquatic ecosystem, the trophic levels can be categorized as follows:
- **Producers:** These are usually phytoplankton or aquatic plants.
- **Primary Consumers:** Herbivores that feed on producers, such as zooplankton.
- **Secondary Consumers:** Small fish that eat primary consumers.
- **Tertiary Consumers:** Larger fish or birds that eat smaller fish.

**Hint:** Visualize the food chain starting from the bottom (producers) to the top (predators).

### Step 3: Analyze the Impact of Contamination
When a water body is contaminated, the toxic substances will first enter the ecosystem through the producers (like plankton). As these producers are consumed by primary consumers (small fish), the toxins accumulate in their bodies. This process continues as secondary consumers (larger fish or birds) eat the primary consumers, leading to even higher concentrations of toxins.

**Hint:** Consider how each level of the food chain interacts with the one below it and how toxins accumulate.

### Step 4: Determine Which Organism is Affected Most
Since biomagnification results in higher concentrations of toxins at the top of the food chain, the organisms at the highest trophic level will experience the most significant effects. In this case, birds, which are tertiary consumers, will have the highest concentration of toxins due to their position at the top of the food chain.

**Hint:** Remember that the higher you go in the food chain, the more toxins accumulate.

### Conclusion
Based on the analysis, the organism that will experience the most marked biomagnification in a contaminated water body is **birds**.

**Final Answer:** Birds