Food chain illustrating DDT bioaccumulation from marsh plants to a red-tailed hawk.

Let's solve each question step by step based on the scenario described in the image.

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Given Information:

- The farmer sprays DDT on a field.
- Wind carries DDT to marsh plants.
- Each marsh plant receives 1 unit of DDT.
- DDT does not break down and accumulates in organisms (bioaccumulation).
- Food chain:
- Marsh plants → Minnows → Perch → Red-tailed hawk

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Question 1:

> Suppose that a minnow eats 100 marsh plants in one year. How much DDT builds up in the body of the minnow?

Each marsh plant has 1 unit of DDT, so:

- 100 plants × 1 unit = 100 units of DDT

✔ Answer: 100 units
Write 100 below the minnow.

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Question 2:

> A perch eats 50 minnows in one year. How much DDT accumulates in its body?

Each minnow has 100 units of DDT (from Q1).

So, 50 minnows × 100 units = 5,000 units of DDT

✔ Answer: 5,000 units
Write 5,000 below the perch.

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Question 3:

> The red-tailed hawk consumes 20 perch in one year. What amount of the pesticide builds up in this consumer?

Each perch has 5,000 units of DDT.

So, 20 perch × 5,000 units = 100,000 units of DDT

✔ Answer: 100,000 units
Write 100,000 below the red-tailed hawk.

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Question 4:

> How does the DDT originally enter the food chain?

DDT is sprayed on the farmer’s field. Wind blows it onto the marsh plants, which absorb it. Since plants are producers and the base of the food chain, DDT enters the food chain through the marsh plants.

✔ Answer: DDT enters the food chain when wind carries it from the sprayed field to the marsh plants, which absorb it.

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Question 5:

> Which organism had the most DDT in their bodies?

From our calculations:
- Marsh plants: 1 unit
- Minnow: 100 units
- Perch: 5,000 units
- Red-tailed hawk: 100,000 units

✔ Answer: The red-tailed hawk has the most DDT.

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Question 6:

> What is the relationship between the trophic level and the amount of DDT found in the body of these organisms?

As you move up the food chain (higher trophic levels), the concentration of DDT increases due to biomagnification — the process where toxins become more concentrated at each higher level because predators consume many prey organisms, accumulating all the toxin from them.

✔ Answer: The higher the trophic level, the greater the amount of DDT accumulated in the organism's body. This is called biomagnification.

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✔ Final Answers Summary:

1. Minnow: 100 units
2. Perch: 5,000 units
3. Red-tailed hawk: 100,000 units
4. DDT enters the food chain via wind carrying it to marsh plants, which absorb it.
5. Red-tailed hawk has the most DDT.
6. Higher trophic levels accumulate more DDT due to biomagnification.

This demonstrates the danger of pesticides like DDT in ecosystems — they can build up to harmful levels in top predators, even if only small amounts enter the environment initially.