Food Webs

Before Video

• A food chain is a sequence of living things in which each one each feeds on the one below it.

• A food web is model made of intersecting food chains.

• Energy in almost all food can be traced back to the sun. Plants use light energy to produce their food through photosynthesis. Plants are then eaten by animals. Those animals are then eaten by other animals.

• A decomposer is organism that eats dead and decaying matter. Common decomposers include bacteria, fungi, worms and beetles.

After Video

• Animals eat other animals to obtain energy and building blocks (nutrients) in order to grow and repair.

• Plants are producers because they produce their own food through photosynthesis. Animals are consumers because they consume plants or other animals.

• An eagle is an apex predator, meaning it is at the top of the food web. Nothing else will attack and eat an eagle. Eagles will eat things like birds, snakes, mice and other animals.

• An apex predator is an animal that feeds on other animals but is at the top of the food web, meaning that it has no predators. Apex predators help control the balance of an ecosystem by keeping the populations of other animals in check.

• Zebras eat grass and they are eaten by predators like hyenas and lions.

• These living things are decomposers. They recycle matter, by breaking down dead and decaying matter. They turn it into nutrients in the soil, which plants use. If ecosystems didn’t have decomposers, dead plants and animals would just pile up.

• Humans over-hunting predators such as wolves can lead to a boom in the population of their prey (deer). This can lead to all those deer eating too much grass. Also, when humans cut down trees (deforestation), soil can erode more easily, affecting fish in streams and rivers. When the population of any of these animals are impacted, so are the animals that eat them. It’s all a delicate balance.