Lesson: Food chains
DO NOW: Draw a picture of a chain with 8 links (circles that make up the chain). What would happen to the functionality of the chain if a link was broken off? Explain.
Review DO NOW: If a link were removed from the chain, the chain would not function properly.
State: In ecology, we have something called a food chain. A food chain shows how energy moves through an environment as an organism eats another organism. Today, we are going to learn how to create food chains, but before we do that, we have to go over some basic vocabulary.
Activity 1: (Circulating Vocab Activity) Form groups of 3-4 students (depends on how many students are in your class. You’ll have 3 words--producers, consumers, decomposers—that students will work on defining with their group. I would suggest having 6 total groups. Have 2 sets of words to circulate in the activity (Vocab worksheet 1). Place the word and definition in each envelop.
Each student will receive a (Verbal and Visual Word Association (VVWA)
worksheet) that they will fill out with the help of their group, while they work collaboratively with each other. The VVWA requires students to: 1) write the word, 2) come up with a picture that represents the definition of that word, 3) Use the word in a sentence and 4) write down a personal association to the word.
Explaining how to fill out a VVWA—Model another example of a word that they’ve already learned, if this is a new process for your students. Perform this prior to letting them try it on their own. (5 minutes)
Give each group one of the 3 words that will be defined that day. Have them complete the VVWA activity with their group for each word. 5-10 minutes for each word/group should be a good range, depending on the size of the groups and their ability levels.
Review VVWA and vocabulary words by having students share their responses. (8-10 minutes)
Activity 2: Give each group a new envelop with various organisms in the (Activity 2 organism worksheet) Teachers: you’ll have to cut these apart prior to placing them in the envelopes!
Have students determine which organisms are producers or consumers. Note: Decomposers are not included in this activity. They should place them in piles on their desks, so that you can come around and gauge their understanding and progress. Once they have made their piles, you can instruct them on how to make a food chain.
Direct instruction: Model how to make a food chain to the entire class. You can use an overhead, a document camera, smart board, or whatever technology you have access to.
State: All food chains have to start with an organism that is capable of making its own energy. This will most likely be a producer. We just learned that a producer makes its own food through photosynthesis. During that process, energy from the sun is converted into sugar that the plant uses to survive. The sugar in plants is also a good source of energy for consumers that eat them. On a food web, when one organism is consumed by another, we represent that with an arrow. The arrow shows the way that the energy is traveling.
For example: If you were to make a food web of you eating a subway sandwich—you would draw an arrow that moves from the sub and points towards you, since you’re getting the energy from it.
The same is true for ecological food chains. Let’s say that one of the producers in the ecosystem that we’re studying is grass. The grass is consumed by a grasshopper. We would draw an arrow from the grass to the grasshopper to represent the movement of energy into the grasshopper.
Next, we would see what eats a grasshopper. A garter snake eats grasshoppers. So we would then draw an arrow from the grasshopper to the snake. We’d then find out what eats a snake, if anything. It turns out that in this ecosystem Red-tailed hawks eat garter snakes. As a result, we would draw an arrow from the snake to the hawk.
Draw this on the board.
Activity 2: Creating food chains with your group.
Have students attempt to make as many food chains as possible on their desk, using the organisms that you gave them in the envelopes. In addition, you should give each group a pile of arrows (ARROW worksheet). The arrows will be placed in between each organism to depict the flow of energy. Instruct students to make as many food chains as they can. However, they should not move organisms around. In other words, once an organism is placed in a chain, it should stay there. It should not be used in a new chain.
Circulate around the room and guide students. If they’re struck on a chain, ask guiding questions like: “What might eat a (fill in the blank).” If you notice an arrow facing the wrong way, make a joke, like: “I didn’t know that a worm could eat a turtle.” They will soon realize that the arrow is facing the incorrect way and fix it. They will remember to double check their arrow positions as a result!
Once you’re satisfied with the progress of the class, you can give them their (food chain reflection worksheet). Have them write down everything that they’ve learned about food chains. This will serve as their notes for today’s class.
Checking for understanding: Give students (exit ticket). They should complete and turn it as they leave class. You can use the exit ticket results to determine who still needs help with food chains at tutoring or during the next class.
Reflection: I think that students get more out of this lesson than the typical activity of drawing a picture of food chain. The cooperative learning aspect promotes discussions and makes learning more active.
|Vocab worksheet 1.doc||
|Verbal and Visual Word Assoc. Worksheet||
|Activity 2 Organism Worksheet.doc||
|Food chain reflection worksheet.doc||
|Example of student food chain Exemplar||