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 solve the question regarding the energy available at the producer level (grass) in the given food chain, we will use the concept of the 10% law of energy transfer in ecosystems.

### Step-by-Step Solution:

1. **Identify the Trophic Levels**:
- In the food chain "Grass → Grasshopper → Frog → Snake → Hawk", we can identify the trophic levels as follows:
- 1st Trophic Level: Grass (Producer)
- 2nd Trophic Level: Grasshopper (Primary Consumer)
- 3rd Trophic Level: Frog (Secondary Consumer)
- 4th Trophic Level: Snake (Tertiary Consumer)
- 5th Trophic Level: Hawk (Quaternary Consumer)

2. **Given Energy at the 4th Trophic Level**:
- The problem states that the energy available at the 4th trophic level (Snake) is 5 kJ.

3. **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. Therefore, to find the energy at the 3rd trophic level (Frog), we can calculate:
\[ \text{Energy at 3rd Trophic Level} = \frac{\text{Energy at 4th Trophic Level}}{0.1} = \frac{5 \text{ kJ}}{0.1} = 50 \text{ kJ} \]

4. **Calculate Energy at the 2nd Trophic Level**:
- Now, we can find the energy at the 2nd trophic level (Grasshopper):
\[ \text{Energy at 2nd Trophic Level} = \frac{\text{Energy at 3rd Trophic Level}}{0.1} = \frac{50 \text{ kJ}}{0.1} = 500 \text{ kJ} \]

5. **Calculate Energy at the Producer Level (1st Trophic Level)**:
- Finally, we can find the energy at the producer level (Grass):
\[ \text{Energy at 1st Trophic Level} = \frac{\text{Energy at 2nd Trophic Level}}{0.1} = \frac{500 \text{ kJ}}{0.1} = 5000 \text{ kJ} \]

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

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