Ecosystems are all around us and can come in any shape or size. It is made up of living, or biotic, creatures like animals, and non-living, or abiotic, things like rocks and water. An ecosystem could be that tiny hill of ants living in your backyard or the entire Amazon Rainforest. All the ecosystems in the world make up the biosphere.

I'm Bruce and I'm Top Dawg down in this aquatic ecosystem. Let me show you how everything works.

Down here, everyone is always chowing down. It's like, "this guy ate this guy but wait he already ate that guy so did that guy eat that guy?" It gets totally confusing so scientists have created food chains to explain what eats what.

This is a simple food chain diagram. The arrows show what has been consumed by what. The grass goes to the grasshopper, the grasshopper goes to the frog, the frog goes to the snake, and the snake goes to the eagle.

Let's explore a food chain using my friends

This is Alvin the algae. He's at the very bottom of a food chain. That doesn't make him a loser though; without the bottom level of a food pyramid, the whole thing would collapse! We all need each other.

Hi, I'm Alvin and I am a producer, or an autotroph! This means I use photosynthesis to create energy. All I'm consuming today are the sweet rays of the sun.

BTW... Autotrophs are organisms that create their own food. Heterotrophs are organisms that eat other organisms to gain energy.

Photosynthesis happens when producers use energy from the sun to turn carbon dioxide and water into oxygen and sugar. Cellular respiration occurs in one of two ways. Aerobic respiration is the opposite of photosynthesis; organisms convert glucose and oxygen back into carbon dioxide and water. Anaerobic respiration is this same process without the use of oxygen and it creates less energy. 

Next, here's my boy Phil the Krill, he is second on the pyramid since he consumes algae.

Yup, I only eat plants and other producers. That makes me a herbivore AND a primary consumer. I guess you could say I'm krilling the game.

Third on the pyramid is Sally the salmon since she eats krill.

Howdy y'all I'm Sally. I'm what they call an omnivore; I like to gobble up some tinier fish and plants. Since I eat primary consumers, I am a secondary consumer. Yeehaw.

Finally, there's me. The toughest one down here. I eat the fish that are smaller than me. That makes me top of the pyramid.

Since I only eat meat, I am a carnivore. Since I eat secondary consumers, I am a tertiary consumer. Big words man.

Trophic Pyramid

Teritary consumer

secondary consumer

primary consumer

producer