Why can’t we be friends?-Community Interactions

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Objective: Students will know that there are many types of ecological relationships between organisms within and across populations in an ecosystem.

Big Idea

It’s not likely that Simba and Timon were ever friends.


5 minutes

Begin with the Warm-Up question, “Which of these shows the best order for the transfer of energy in an ecosystem?”

a)    Producer-decomposer-herbivore-omnivore

b)    Carnivore-herbivore-decomposer-omnivore

c)     Producer-herbivore-carnivore-decomposer

Allow 2-4 students to respond. Although this content was covered in a previous lesson, expect students to differ in their responses to this question.  Allow students to engage in academic discourse.  Require students to provide rationales for their responses.  Give those who do not volunteer to answer the question an opportunity to participate by asking them to show their agreement by raising their hands.  Act as a facilitator for the discussion.  Ensure that the discussion ends with the correct response clearly communicated.  Be sure to provide a concise rationale for the correct answer.

Introduce New Material

20 minutes

Ask students to say the first word that comes to mind when they hear the term, relationship. Use chart paper to write down the words and phrases that students say.  This is a “free-think” activity so allow students to state the most immediate word that comes to mind when they hear “relationship” in order to help them gain clarity on exactly what the term relationship means to them.  This type of self- identification will help students compare and contrast what they know to be true about the term, relationship with what they will learn in the today’s lesson.

Explain that we will come back to the words that they associated with the term relationship later in the lesson after we watch a few video clips of ecological relationships.  Note: These clips and other informative clips can be found on the Discovery education website. It's a FREE and very useful site for planning engaging instruction.  You have to create an account but it's worth the trouble for the various forms of science information you will find.

Remind students of the viewing expectations.   Instruct students to watch the three clips.  Establish the purpose for viewing and let students know they should be able to discuss how a relationship is evidenced in each clip.  Watch the following clips:

Stop after each clip to briefly highlight key points from each video.  Ask students to explain the nature of the relationship between the organisms highlighted in each clip.  For example, look for students to note that relationships can be beneficial or harmful.

Ask students to explain why predation represents a relationship.  Point out the misconception that relationship means that the association between organisms is always beneficial.  Clarify that relationships are not based on associations being beneficial ones, but relationships are based on the close association between the organisms, whether beneficial or not.

Introduce the new vocabulary: habitat, niche, relationship, symbiosis, competition, predation, intraspecific competition, interspecific competition, consume, mutualism, parasitism, commensalism, coevolution

As always, identify those terms with prefixes, suffixes, Greek or Latin root words. Instruct students to add those terms to their vocabulary maps, an ongoing record of root words and prefixes/suffixes that will help students build their vocabulary and increase literacy.

Display visual information as you teach and instruct students to take notes using guided notes that you have provided or use a note-taking strategy that you have taught. Guided notes provide more support for the different learning styles of students.

Take time to clarify the difference between intraspecific and interspecific competition, focusing on the prefixes intra- and inter- to help students establish the difference between the two. 

After clarifying the difference between the two terms, check for understanding around the difference.  Display 4-5 competition descriptions.

Ask students to engage in “think, pair, share” to identify each description as interspecific or intraspecific. Think, pair, share involves students first organizing their own thoughts about a topic before then “pairing” with one classmate to talk about that topic, followed by “sharing” the thoughts discussed by the two with two or more other students.

Use symbols to help students recall the nature of these three symbiotic relationships:

  • Mutualism, ++
  • Commensalism, +±
  • Parasitism, -+

Locate a few “exotic” parasite images to show the class.  High school students are always eager to see the more “yucky” images of parasites like the Bot fly.  The parasite images tends to draw unlikely students into the discussion.


Guided Practice

15 minutes

Display a word bank of terms and a set of descriptions.  Explain that the task involves matching the correct term with its description.  Perform a “think aloud” to answer the first 2 questions with the class.  “Think aloud” allows students to see the thinking process that leads to identification of the correct response to a question.  Instruct students to perform a second “we do together” working with a partner to complete the remaining worksheet. 

This practice should be performed with relatively little difficulty with the students working together.  It serves as a reinforcement of concepts and helps students make sure that they understand the concepts before moving into the independent practice, where they will work alone.

Independent Practice

20 minutes

Distribute paper and markers.  Ask students to randomly draw a slip of paper with a term listed on it from a container.

Display instructions for completion of a  literacy activity called, “What is it, what is it like?”  This is an activity that helps students deepen their knowledge of key vocabulary terms associated with the instruction.  Explain and how students how to fold their paper into fourths and complete each of the sections as follows:

  1. What is it?- Define the term.
  2. Write the term below the definition.
  3. What is it Like?- List 3 non-science analogies or similes of the term and include 1 visual image or symbol of the term.
  4. Examples- List 2 specific science examples.

Walk around to ensure that students have folded their paper correctly.  Listen for student misconceptions as they work independently to complete the assignment.  Inform students that working independently does not mean that they cannot talk with their classmates.  It only means that the work should be completed without assistance from peers, unless it is stated that the grade is a group grade.

Look for the creative non-science analogies (What is it like?) that demonstrate a depth of understanding about the term.  For example, one student work sample indicates a marriage, family or a team to be like symbiosis. Another shows a "moocher", one who donates, and husband and wife all like symbiosis.  The latter student example shows that the student understands that symbiosis is not always beneficial to both organisms. This assignment allows the teacher to pick up on misconceptions, as well. One work sample indicates eating a hamburger is like predation.  This is a misconception that can be corrected in a conversion with the student after reviewing the work. Overall, look for the students' work to show you how much they know and how well they can relate the concepts beyond the classroom.

Lesson Close

5 minutes

Display the following table on a LCD projector.  Work as a whole group to fill in the following chart concerning symbiotic relationships.  Organisms A initiates the behavior.

Use the following terms: Benefits, Harmed, and Not Affected to complete the table. Listen for incorrect reasoning and correct misconceptions that arise within the choral responses from the class.  Stop and address incorrect responses. For example say, "Okay, I think I heard a few voices saying both benefited in parasitism."  Use guided questions to help students identify the correct answer, "Am I benefited when a tick bites me?" 

Use observations from this activity to determine whether remediation of concepts is needed before moving forward. If the majority of the class is able to respond chorally to this table, then it is likely that no further instruction is needed.


Symbiotic Relationship

Organisms A

Organisms B