The Tree/Web of Life (Lesson 15: Let us stop and think)

Tree or Web of life? Let us stop and think
[ezcol_1quarter]Main Idea:[/ezcol_1quarter] [ezcol_3quarter_end] Earth hosts many, many organism that are related to each other, and all these creatures interact to make the great Web of Life. This lesson and activity emphasize the inter-dependence of organisms, and the concept that changes in one part of a biome provoke changes in another part of the same biome.[/ezcol_3quarter_end]

[ezcol_1quarter]Objectives:[/ezcol_1quarter] [ezcol_3quarter_end] 1. To understand that ALL organisms are related and that they interact with other organisms, forming a great “Web of Life.”
2. To use a graphic organizer to represent relationships among creatures.
3. To be able to describe that organisms depend on other organisms and on their environments for their survival and success.

[ezcol_1quarter]Students’ Skills:[/ezcol_1quarter] [ezcol_3quarter_end] Observation, application, analysis, making use of knowledge, synthesis. These skills were drawn from Bloom’s Taxonomy and the constructivist list. NGSS connections: MS-LS1 From Molecules to Organisms: Structures and Processes; MS-LS2 Ecosystems: Interactions, Energy, and Dynamics; and MS-LS4 Biological Evolution: Unity and Diversity.[/ezcol_3quarter_end]

[ezcol_1quarter]Materials[/ezcol_1quarter] [ezcol_3quarter_end] 1. Forthe lecture and discussion: textbooks, material reference, a PowerPoint slide showing a pond with different types of animals and plants, and the Tree of Life.
2. For the activity:  ribbon/yarn of different bright colors. Handout, cards depicting animals, plants, Sun, and water (rain). [/ezcol_3quarter_end]

[ezcol_1quarter]Lesson:[/ezcol_1quarter] [ezcol_3quarter_end]1. Start the class by inviting the students to present their posters from the last class on “great transformations in life.”

2. Entry card: Write two sentences about how you influence or are connected to another creature or thing (rain, wind, etc.) in your environment. Allow students time to ponder and write down their answers. Discuss the importance of learning about interdependence among creatures, and how this lesson relates to past lessons. Write the objectives on the board.

3. Explain to the students that among the thousands of organisms living on Earth, they have studied only a very few examples of them. Use the Tree of Life to illustrate that we ALL came from the same ancestor, and therefore are related and have characteristics in common. Remind the students of the cladograms they made, and how the Tree of Life is a much more complete depiction of life. However, we can also think of life as a Web because of the inter-relationship among organisms, and organisms and Earth.

4. In the activity, the students’ goal is to construct a web of life representing the interconnections in a pond. This activity has two parts. Part I, drawing from a slide of a pond, the students should produce a list of animals, plants, and things. Then, in groups of three, students should enter the names of four such items at the corners of the organizer (a diamond shape). Working as a group, they will join all the items (two at a time) with a line, and write on the line the type of relationship between the things (six connections). For example: predator-prey, competition, cooperation, etc.

5. Part II: Ask students to gather around, sit in a big circle, and bring their organizers to the circle. Ask them what items they used in their organizers and distribute a card representing animals, plants, and things like the sun and water. The cards should be visible to all students. See the teacher’s notes. Invite one of the groups to follow their organizers and connect themselves with another group using colorful yarn or ribbons. While one student does this, another student should explain what type of relationship the two items have. Repeat this with every group; by the end there should be a thick web of connections.

6. Start a whole-class discussion, leading toward questions such as: “What will happen if the sun disappears? How is the insect in the pond important? What would a lot of water or too little water do to the pond diversity? Are microorganisms important?”

7. Remind the students that the next class will be a field trip to the museum and that the concepts talked about in this class will be relevant.

8. Exit card: Pick one item from the class activity and write three sentences about its importance to the well-being of other organisms in the pond.


[ezcol_1quarter]Class Closing:[/ezcol_1quarter] [ezcol_3quarter_end]
1. Collect entry/exit cards.

2. Homework: Bring your parent field trip consent and a lot of energy and enthusiasm. [/ezcol_3quarter_end]

[ezcol_1quarter]Assesment:[/ezcol_1quarter] [ezcol_3quarter_end] 1. Participation in class and discussions. Presentation of results, and thoroughness and detail in completing their work.
2. Grading: entry/exit cards.
3. Use a general rubric to evaluate the students’ overall performance.[/ezcol_3quarter_end]

[ezcol_1quarter]Teacher’s Reflections[/ezcol_1quarter] [ezcol_3quarter_end]1. Things that I did not cover.
2. Did I meet the lesson objectives?
3. Comments, conclusions, and modifications.
4. Pedagogical value of the lesson. Did my students learn the concepts and ideas explored in this class? Did the assessments provide enough evidence of understanding?[/ezcol_3quarter_end]

[ezcol_1quarter]Notes to the Teacher[/ezcol_1quarter] [ezcol_3quarter_end]1. Have in hand duplicate cards containing the names or pictures of the animals, creatures, or things that make a pond. One set is given to the group using it for the organizer, and the other set of four is distributed randomly among the other groups. The purpose is to have overlaps when constructing the web in the circle. This is because organisms interact with more than one item.

2. The list of items should contain: sun, water, ducks, water lilies, turtles, fish, algae, protist (paramecium), beavers, birds, bacteria, flies, beetles, mosquitos, ferns, water plants, grasses, trees, flowering plants, bees, worms, snakes, spiders, frogs, salamander, birds, raccoons, rabbits, rats, mice, and moles.

3. The idea is that the students will start the visit to the museum with some knowledge as to the connections between all living things, and the importance of preserving and taking care of each species. The curriculum goals for the museum visit presume that the students already know something about biodiversity; thus, the field trip will expand students’ understanding of that topic. This pre-field trip lesson and activity in class highlights the main aim of the museum visit. This is so that the students will have some idea of what topics they are expected to investigate during the trip, so they can make the best use of their time and resources.

4. It is important that the teacher provides scaffolding to make sure that students learn what they need to know; mainly, that organisms are intertwined and that changes in one aspect of an ecosystem affect another area of the same ecosystem.

5. The activity requires that the teacher use prompts and guide the discussion so that the students discuss relevant ideas. Also, the teacher can provide content where needed.



Tree or Web of life? Let us stop and think

cropped-owlet_logo.gifOur blue-green planet Earth hosts many, many organisms that are related to each other, and they all interact to make the great “Web of Life.” In this lesson, we are going to explore the interdependence of organisms and how changes in one part of a biome provoke changes in another part of the same biome.


Part I:
1. Look at the PowerPoint slide of a pond and at all the animals, plants, and things that make the pond a habitat. When prompted, contribute to the list of things that make a pond.

2. Your teacher will place you in groups of three students. Look at the list on the board and call out the names of four such items so that they can be marked on the board. Then, use the diamond shape below and write at the corners (blue ovals) of the organizer the names of the items you picked. Working as a group, join all the items (two at a time) with a line, and write on the orange line the types of relationships between the things. You should have a total of six connections.




Part II:

3. When your teacher indicates, gather around, sit in a big circle, and bring your organizer to the circle. Remind your teacher of the four items your group chose for your organizer, and you will receive four cards representing your chosen animals, plants, or things, plus four other cards.

4. When called by your teacher, connect with another group using the organizer’s results as a guide (for example, sun connects to flower). While one student in your group does this, another student should explain the type of relationship (for example, the flower uses the sun’s energy to make oxygen and food). Repeat this with every item, and follow the teacher’s guidance.

5. After everybody is finished, your teacher will ask several questions. Participate as much as you can, ask questions, and think about the connections made.

6.  In the space below, describe ONE situation in the pond where one organism depends on other organisms and on their environment for survival and success.







7. What would happen if this organism disappears?