Question

Shorter food chains provide greater available energy. Why?

Answer 1

Hint: The food chain is an important part of our ecosystem. It gives us the relationship among various types of organisms. It follows a 10% law, where the most of the energy is lost and only 10% of the energy is passed on to the next and successive trophic levels.

Complete Answer:
Food chain is a chain reaction which tells us what eats what. It is a linear sequence which gives information regarding the energy as well as how the nutrients are transferred from one organism to another. Each step in the food chain represents the trophic levels. So, the food chains begin with the producer organisms which prepare the food. This is followed by the primary, secondary and tertiary consumers. These are the main parts of the food chain.

Let us discuss each one of them.
- Sun: The major source of energy. It provides energy to all living beings.

- Producers: It includes all the green plants as it is the first stage of the food chain. All the green plants are able to perform photosynthesis to prepare their own food. They absorb the sunlight and use the available gases to form the food. They are also known as autotrophs.

- Consumers: They obtain the next trophic levels in the food chain and include the organisms which are dependent on the producers for their food. It is the largest part of the food chain as they are more in number as compared to the plants. The organisms in consumers can be herbivores, carnivores or omnivores. The herbivores consume the green plants, carnivores consume the animals whereas the omnivores consume both. So, the herbivores become the primary consumers, carnivores become the secondary consumers whereas the omnivores become the tertiary consumers.

- Decomposers: They attain the last trophic level in the food chain as they are the organisms which feed on dead and decaying matter of organisms. They feed on the organic matter of these dead organisms and convert it into inorganics nutrients.

10 percent law: The green plants absorb 1% of the energy from the sun and pass on 10% of their own energy to the successive trophic levels. This way each trophic level obtains only 10% of the previous energy. Thus, when the food chain is short, the availability of energy is more as the loss of energy is less. When compared to longer food chains, the loss of energy will be more and thus is not favorable.

Note: Food chain is a linear sequence of levels which shows the eating pattern of different organisms. Each level in this chain is represented by a trophic level. And when many such food chains combine, it forms a web kind of structure known as food web.