Why do food chains start with plants

Again, discuss the connections between primary, secondary, and tertiary consumers. Next add the scavengers: hyenas can be predators as well as scavengers and vultures. Finally, discuss decomposers—bacteria, fungi and worms that feed on the decaying matter—and their role in the food web.

Students should now have a complete understanding of the complexity of the food web. At right is an example of a food web. All living things need energy to stay alive. This energy comes from the sun. Plants make their food from energy from the sun. Animals get their energy from the food they eat. Animals depend on other living things for food. Some animals eat plants while others eat other animals. This passing of energy from the sun to plants to animals to other animals is called a food chain.

Ask students to name all the different animals that are dependent on the one tree. First demonstrate a food chain, a simple interdependence , by linking the student with the sun card the source of all energy to the student with the grass card to the student with the zebra card to the student with the lion card.

Balance is key! Explain that the interactions in a grasslands system are more complicated than this. Have the participants now stand in a circle, out of order i. Give the ball of string to the person with the sun. Then ask that person to pass the yarn to the person with a card of an organism that the sun supports. If the sun supports more than one organism in the circle, pass the string back to the sun and from the sun to the other organism that it supports.

Keep going through the chain until you get to the top consumers. The string will be a tangled web in the middle of the circle. Food chains are complicated, and the balance they create is essential. For example, the impact of overhunting will cause the lions to drop their strings. What happens? This activity requires a large open area. In a class of 25 to 40 students, choose three to five to be predators and seven to ten to be plant-eaters.

The remainder will be plants. This represents a balanced system where plants are more plentiful than plant-eaters, plant-eaters more plentiful than predators, and predators are the least plentiful.

The students can select which plant-eaters and predators will be in their groups. Each group selects hand-signals that will differentiate them from the other groups.

Example: the plants may want to hold their hands out to their sides to represent leaves, the plant-eaters oryx may hold their hands on the heads to represent horns, and the predators lions may hold their hands up like paws with the claws showing. The predators try to tag the plant-eaters who try to tag the plants. Since predators decompose when they die and become fertilizer, the plants try to tag the predators. Once you are tagged, you turn into whatever tagged you.

After a period of time, stop the game to see how many plants, plant-eaters, and predators are left. Play should resume but should be stopped a few times before the end to determine what has happened and why. After playing a few rounds of the game, select one of the plants to re-enter the game as a human.

The rules for the human are different: the human can tag anyone, but no one can tag the human. Each time the human tags someone, that player becomes another human. See how long it takes before all players have become changed into humans.

Discuss the changes and relationships that the game illustrates. Some questions for discussion might include:. Sign up for our Interactive Classroom - Coming Soon! Teaching Standards. Objectives Students will learn about food chains , pyramids, and food webs.

Background A food chain shows how each living thing gets its food. Food chains can also be represented in different forms such as this pyramid.

Materials Food Chains Enough strips of colored paper so that each student has four, one on which to draw the sun, one on which to draw a producer, one on which to draw a primary consumer and one on which to draw a secondary consumer.

Food Web Blank cards Colored pencils Yarn. Vocabulary Carnivore: an organism that eats mostly meat Consumer: an organism, usually an animal, that feeds on plants or other animals Food chain: a sequence of organisms arranged in such a way that each feeds on the organism below it in the chain and serves as a source of food for the organism above Food web: all the connected or linked food chains within an ecological community Herbivore: an organism that eats mostly plants Predator: an animal that lives by killing and eating other animals Producer: an organism, usually a plant, that converts sunlight energy into living material; usually the first step on the food chain or food web or first trophic level of a food pyramid.

Preparation Cut enough strips of paper so that each student will have four. Food Webs Note: This activity can be added for older students. Discussion All living things need energy to stay alive. Possible Questions Do you know why there are more herbivores than carnivores? What if one animal from the food chain disappeared?

What about one level of the food chain? How do humans fit in the food chain? What could happen if an animal not native to an area is brought into the local food chain? What could happen if you remove an animal from the food chain? How can sun and rain affect the food chain? Why is a food web a more accurate depiction of nature than a food chain or pyramid? Extension 1. Give each participant a picture. Show the impacts of man on the simple food chain.

Man can: Cut trees no trees, nothing for grazers to eat, grazers will die, lions and other predators will have nothing to eat.

Toggle navigation. Language English. Food chains and food webs Black-crowned night-heron. This predator is adapted to hunt at night. In the French Guiana this is one of the major night heron species with its cousin the Yellow-crowned night-heron Nycticorax violacea. Feeds mainly on aquatic animals, including fish, amphibians and insects. Coastal swamps. Every plant and animal species, no matter how big or small, depends to some extent on another plant or animal species for its survival.

It could be bees taking pollen from a flower, photosynthesis of plants, deer eating shrub leaves or lions eating the deer. A food chain shows how energy is transferred from one living organism to another via food. It is important for us to understand how the food chain works so that we know what are the important living organisms that make up the food chain and how the ecology is balanced.

Photosynthesis is only the beginning of the food chain. There are many types of animals that will eat the products of the photosynthesis process. Examples are deer eating shrub leaves, rabbits eating carrots, or worms eating grass. When these animals eat these plant products, food energy and organic compounds are transferred from the plants to the animals.

These animals are in turn eaten by other animals, again transferring energy and organic compounds from one animal to another. So for how many levels does this go on? To follow the food chain to its different levels and know how it works go to this site.

The page also contains names and definitions of terms used to describe the 'players' in the food chain- producers, consumers, herbivores.

You can also refer to the diagrammatic representations of food chains, food webs and ecological pyramids. A food chain describes how energy and nutrients move through an ecosystem.