What is a food chain?

All living things depend on each other to live. The food chain shows how some animals eat other animals to survive. While being food for animals higher in the food chain

these animals may eat other animals or plants to survive. The food chain is a plex balance of life. If one animals source of food disappears

such as from over fishing or hunting

many other animals in the food chain are impacted and may die. Let's look at o examples of food chains

one in the water and the other on land. In the Sea All sea creatures rely on other sea creatures for food to survive. At the bottom of the food chain are the sea plants and plankton. Many types of fish and animals such as the snail

shrimp

jellyfish

and sea star eat the plankton. The *** all animals and fish who eat plankton then bee food for larger fish

such as the tuna and mackeral. These fish are then eaten by larger fish and animals

such as the shark and dolphin. And who eats the shark? Check out the menu at a seafood restaurant next time you are eating there. Don't be surprised if you find shark on the menu. On Land The food chain on land is just as plex as in the sea. Small animals eat plants or bugs. Larger animals then eat them

with even larger animals eating them. Who is at the top of the food chain? That's us! We hum eat many of the plants and animals on earth. That's why we rely so heavily on all plants and animals for our existance. A break in the food chain can impact everyone. Here is a simple example of a food chain in the wild The zebra eats grass for its food. And who eats the zebra? Larger predators like the lion eat the zebra.

Food chains

food webs and/or food neorks describe the feeding relationships beeen species in a biotic munity. Food webs graphically represent the trfer of material and energy from one species to another within an ecosystem. Typically a food web refers to a graph where only connections are recorded

and a food neork or ecosystem neork refers to a neork where the connections are given weights representing the quantity of nutrients or energy being trferred. As usually diagrammed

an ani *** is connected to another ani *** for which it is a source of food energy and material by an arrow representing the direction of biomass trfer. Organi *** s are grouped into trophic levels—from the Greek word for nourishment

trophikos—based on how many links they are removed from the primary producers. Primary producers

or autotrophs

are species capable of producing plex anic substances (essentially "food") from an energy source and inanic materials. These ani *** s are typically photosynthetic plants

bacteria or algae

but in rare cases

like those ani *** s forming the base of deep-sea vent food webs

can be chemotrophic. All ani *** s that eat the autotrophs are called heterotrophs. They get their energy by eating the producers. 图片参考：upload.wikimedia/ *** /mons/f/fc/Foodweb

参考: Food chains

pyramids of number and biomass designed for teens