In a food chain, the total amount of living material is depicted by:

Options

A. Pyramid of biomass
B. Pyramid of energy
C. Pyramid of number
D. Trophic levels

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the representation of the total amount of living material in a food chain. This is a key concept in ecology, particularly in understanding how energy and biomass flow through an ecosystem.

2. **Identifying the Options**: The options given are:
- Pyramid of biomass
- Pyramid of energy
- Pyramid of numbers
- Trophic levels

3. **Defining Pyramid of Biomass**: The pyramid of biomass refers to the total mass of living organisms at each trophic level in a food chain at a specific time. It visually represents how much living material is present in each level of the food chain.

4. **Defining Pyramid of Numbers**: The pyramid of numbers shows the number of individual organisms at each trophic level. This does not directly represent the total living material, as different species can have vastly different biomass.

5. **Defining Pyramid of Energy**: The pyramid of energy illustrates the amount of energy available at each trophic level. While energy is crucial for understanding ecosystem dynamics, it does not represent living material.

6. **Understanding Trophic Levels**: Trophic levels are the different positions that organisms occupy in a food chain, such as producers, primary consumers, secondary consumers, etc. They do not directly depict the amount of living material.

7. **Conclusion**: Given the definitions and explanations of the options, the correct answer to the question is the **pyramid of biomass**, as it specifically represents the total amount of living material at each trophic level in a food chain.

**Final Answer**: The total amount of living material in a food chain is depicted by the **pyramid of biomass**.

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