In the given food chain, suppose the amount of energy at fourth trophic level is 5 kJ, what will be the energy available at the producer level ?
`"Grass"to"Grasshopper"to"Frog"to"Snake"to"Hawk"`

Options

A. 5 kJ
B. 50 kJ
C. 500 kJ
D. 5000 kJ

Explanation

To find the energy available at the producer level in the given food chain, we will use the 10% law of energy transfer in an ecosystem. Here are the steps to solve the problem:

### Step-by-Step Solution:

1. **Identify the Trophic Levels**:
- The food chain is: Grass (Producer) → Grasshopper (1st Trophic Level) → Frog (2nd Trophic Level) → Snake (3rd Trophic Level) → Hawk (4th Trophic Level).
- The energy at the 4th trophic level (Hawk) is given as 5 kJ.

2. **Apply the 10% Law**:
- According to the 10% law, only 10% of the energy from one trophic level is transferred to the next trophic level.
- This means that the energy at each lower trophic level is 10 times greater than the energy at the level above it.

3. **Calculate the Energy at the 3rd Trophic Level (Snake)**:
- Energy at the 4th level (Hawk) = 5 kJ.
- Energy at the 3rd level (Snake) = 5 kJ / 10% = 5 kJ / 0.1 = 50 kJ.

4. **Calculate the Energy at the 2nd Trophic Level (Frog)**:
- Energy at the 2nd level (Frog) = 50 kJ / 10% = 50 kJ / 0.1 = 500 kJ.

5. **Calculate the Energy at the 1st Trophic Level (Grasshopper)**:
- Energy at the 1st level (Grasshopper) = 500 kJ / 10% = 500 kJ / 0.1 = 5000 kJ.

6. **Identify the Energy at the Producer Level (Grass)**:
- The producer level (Grass) is the first trophic level, which has an energy of 5000 kJ.

### Final Answer:
The energy available at the producer level (Grass) is **5000 kJ**.

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