Question

Food chains and food webs are like flow diagrams. They show how energy flows between plants and animals. Where does the energy originally come from?

Answer 1

Hello there. I tried to make a drawing but the tool wouldn’t let me. Anyways I’ll try to explain this to you. So what I’m about to show you below is a food chain and each of the organisms has a category.
Grass —> Bug —> Bird —> Snake —> Hawk
1. (Primary Producers & Consumers)
Starting with the grass, it would be labeled as one primary producer. That grass goes on to be consumed by a bug. The bug would be labeled a primary producer since it is the main organism to consume the grass. The grass is energy for the bug.
2. (Secondary,Tertiary, & Quaternary Consumers)
Next the bug (primary consumer) would be consumed by the bird, and the bird is a secondary consumer. So energy is provided to the bird as it consumes the bug.
Then the bird is eaten by the snake. The snake would be a tertiary consumer and it gets its energy by eating the bird.
Finally, at the top of the food chain, we have the apex predator aka the hawk. The hawk consumes the snake, and the hawk is a quaternary consumer. The hawk gains energy by eating the snake.
So throughout this food chain, energy is passed on as each organism feeds on another. Now in scientific terms, only 10% of energy from each organism is passed on. So for example, if the grass had 20,000 kilocalories of energy, only 10% of that energy or 2,000 kcal would be passed on to the bug. And so forth.
Now if we were to delve into this further, the grass gets energy from water and sunlight. If we were to meticulously identify what other energy is behind this, we would talk about this topic infinitely.
As a final conclusion: energy did not just randomly originate throughout this food chain, it is passed on through each trophic level. If you really wanted to find a starting point in the food chain, you could start with the primary producer.
Hope this helped :)
- Pusheen