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Ecological Balance

Lesson Plan

Ecological Balance

Objectives

In this lesson, students will gain a general understanding of ecological balance. Students will be introduced to how various relationships affect balance in ecosystems. Students will:

  • define ecology.
  • observe and describe examples of relationships between organisms in the local ecosystem.
  • recognize the role of competition among organisms in an ecosystem.
  • distinguish between and identify examples of symbiosis, commensalism, mutualism, and parasitism.
  • identify animals that live in each type of symbiotic relationship.
  • explain that symbiotic relationships are examples of the intricate web of interdependence within which all plants and animals live.

Essential Questions

Vocabulary

  • Biome: A large geographical area with certain plant and animal groups, which are adapted to that particular environment. The biome depends on the climate and geography of a region. Biomes are many similar ecosystems grouped together.
  • Biosphere: Part of the Earth that supports life, including the top portion of Earth’s crust, the atmosphere, and all the water on Earth’s surface.
  • Carrying Capacity: Largest number of individuals of a particular species that an ecosystem can support over time.
  • Commensalism: A type of symbiotic relationship in which one organism benefits and the other organism is not affected.
  • Community: All the populations of different species that live in an ecosystem.
  • Consumer: Organism that can’t create energy-rich molecules but obtains its food by eating other organisms.
  • Ecology: The branch of biology concerned with the relationships between organisms and their environment.
  • Ecosystem: A system formed by the interaction of a community of organisms with their physical environment.
  • Habitat: The areas where an organism lives, grows, and develops.
  • Limiting Factor: Anything that can restrict the size of a population, including living and nonliving features of an ecosystem such as predators or drought.
  • Mutualism: A type of symbiotic relationship in which both organisms benefit.
  • Niche: In an ecosystem, refers to the unique ways an organism survives, obtains food and shelter, and avoids danger.
  • Parasitism: A type of symbiotic relationship in which one organism lives on or in another organism, called the host. The parasite benefits and the host is harmed.
  • Population: The total number of organisms of one species in a specific area.
  • Predator: An animal that hunts and eats other animals.
  • Symbiosis: A relationship between two organisms living close to one another; types of symbiosis are commensalism, mutualism, and parasitism.

Duration

90 minutes/2 class periods

Prerequisite Skills

Prerequisite Skills haven't been entered into the lesson plan.

Materials

www.saburchill.com/ans02/chapters/chap019.html

Related Unit and Lesson Plans

Related Materials & Resources

The possible inclusion of commercial websites below is not an implied endorsement of their products, which are not free, and are not required for this lesson plan.

Formative Assessment

  • View
    • During the lesson, confer with students to determine if they understand ecological balance. This can be done by asking questions of the entire class or asking students individually.
    • Place students in small groups. Put the following question on the board: How do organisms in your body and your environment help to provide an ecological balance? Students should discuss the questions within their groups. After giving students about five minutes, meet with each group. Listen to their responses and make corrections to their understanding.
    • Collect science journals for individual assessment.
    • Collect and check the Dirty Observations Lab worksheet, the Competition—Guided Reading Questions, and the Examples of Symbiosis worksheets.

Suggested Instructional Supports

  • View
    Scaffolding, Explicit Instruction
    W: In this lesson, students will investigate balance in ecosystems. Emphasis will be placed on symbiotic relationships. At the end of the lesson, students will be able to discuss the various components of an ecosystem, the role of predator versus prey, and competition within an ecosystem, and distinguish between three types of symbiotic relationships.
    H: Students will begin the lesson by learning the origin of the word ecology and then complete an ecology vocabulary worksheet which can be used to assess prior knowledge.
    E: Students will engage in an outdoor activity where they will observe a small sample of an ecosystem. Students will work in small groups to answer questions on their observations.
    R: Students will complete a worksheet asking them to determine what type of symbiotic relationship is being described: mutualism, commensalism, or parasitism.
    E: As a closing activity, students will write down three interesting facts that they learned in today’s lesson. You will then share some of the responses given with the class. This will serve as another way to review the concepts.
    T: In this lesson, students will engage in a variety of activities including an outdoor activity, completing graphic organizers, and working in small groups.
    O: By participating in the warm-up, students will begin the lesson with an assessment on what they already know about the term ecology. Students will move to independent learning by completing graphic organizers and completing a summative assessment of what they learned in this lesson.

Instructional Procedures

  • View

    In preparation for the lesson, read through the Dirty Observations Lab (S-7-7-2_Dirty Observations Lab.doc) and select an area on the school ground where it is permissible for students to remove small soil samples.

    Day 1

    Begin the lesson by writing the word ecology on the board. Say to students, “Today we will continue studying ecology. Give me some examples of what you believe an ecologist studies.” Record student responses as they give them.

    Explain to students that ecology is a branch of biology. Ecologists are scientists who study ecology. The term ecology comes from Greek words that mean “study of the household.” Ask students to infer how ecology is like a study of a household.

    Hand out a copy of the Ecology Vocabulary Worksheet (S-7-7-2_Ecology Vocabulary Worksheet and KEY.doc) to each student. Have students work in cooperative learning groups to complete the “What We THINK This Term Means” column on the worksheet.

    After groups have completed the Ecology Vocabulary Worksheet, check their responses as a class, correcting student understanding where necessary. Define each term on the board and have them fill in the “This IS What This Term Means” column on the worksheet.

    Let students know that the next activity will take place outside. Prepare students for the outdoors and gather materials for the Dirty Observations Lab activity. Give students the Dirty Observations Lab directions (S-7-7-2_Dirty Observations Lab.doc).

    Dirty Observations Lab

    Take the class outside and divide the class into teams. Each team should choose a site to observe. Assist students as they insert the four wooden sticks into the ground to form a 1-meter by 1-meter square and wrap the string around them.

    Have students observe closely what is within the boundaries of the ecosystem. Then have students dig up a sample of soil from the ecosystem and place it in a previously prepared observation box. The observation box will consist of a box top lined with plastic wrap. Students should put the dirt inside the observation box and take it indoors for further investigation.

    Have students answer the Dirty Observations Lab questions and conclusion together in their groups.

    After students have answered the questions, discuss why there were variations in living and nonliving things observed or collected within the ecosystem.

    Day 2

    In preparation for the lesson, read through the Aquatic Ecosystem Lab procedure (S-7-7-2_Aquatic Ecosystem Lab.doc). Obtain pond water from a local source or order it from a biological supply company. Set up microscope stations before class, if possible.

    Note: For the Aquatic Ecosystem Lab, students should have prior experience using the microscope, slides, and cover slips. If students are unfamiliar with preparing wet mount slides, provide them with the How to Prepare a Wet Mount Slide procedure (S-7-7-2_How to Prepare a Wet Mount Slide.doc).

    Prior to conducting the lab, give students the Microorganisms article to read (S-7-7-2_Microorganisms.doc). Discuss the following questions with students:

    • “In which of Earth’s ecosystems do microorganisms live?” (all of them)
    • “Can you identify some microorganisms you are already familiar with?” (Answers will vary.)
    • “When are microorganisms helpful to plants?” (They are helpful when they act as decomposers and recycle nutrients into the soil, and when they provide nitrogen for plants.)
    • “When are microorganisms harmful to other organisms?” (They are harmful when they invade host organisms and cause disease.)

    Hand out to students copies of the Aquatic Ecosystems Lab directions (S-7-7-2_Aquatic Ecosystem Lab.doc) and How to Prepare a Wet Mount Slide (S-7-7-2_How to Prepare a Wet Mount Slide.doc). Provide each group with a sample of pond water. Students should put the water on a slide, cover it with a cover slip, and observe the drops under the microscope. Students should record their findings in their science notebooks, such as an illustration and written description of what they saw. Students should also answer the question in their science notebooks: “How do microorganisms support ecological balance?” Have each group present its findings to the rest of the class. Discuss what was similar and different among all of the groups’ findings.

    After wrapping up the Aquatic Ecosystems Lab with the class, say to students, “Now that we have discussed ecology and have learned about the different components of ecosystems, let’s discuss symbiosis. Symbiosis means living together. There are three different types of symbiotic relationships: parasitism, commensalism, and mutualism.”

    Hand out a copy of the Symbiosis worksheet to each student (S-7-7-2_Symbiosis Worksheet and KEY.doc). If you have a document camera, project the worksheet on your board. Work with students to fill in the graphic organizer. Have students use their background information and vocabulary to familiarize themselves with the concept of symbiosis and examples of these relationships.

    Hand out the Examples of Symbiosis worksheet (S-7-7-2_Examples of Symbiosis and KEY.doc). Allow students time to work independently in order to complete the worksheet. Go over the correct answers with the class.

    After reviewing the correct answers with the class, project the following Web site on the board: www.saburchill.com/ans02/chapters/chap019.html. If the Internet is not accessible, hand out a copy of “The Ecosystem: An Inter-acting Community” (S-7-7-2_The Ecosystem.doc), and the Competition–Guided Reading Questions (S-7-7-2_Guided Reading Questions and KEY.doc). After students complete the worksheet, go over the correct answers.

    As a closing activity, hand out three sticky notes to each student. Say to students, “I would like you to write down three interesting facts you learned about symbiosis. Once you finish writing three facts, post them on the board.” Give students about five minutes to brainstorm. After students have posted their facts on the board, go over several of them with the class. Also, use this time to answer any remaining questions.

    Extension:

    • For students who may need an opportunity for additional learning, describe examples of symbiotic relationships that humans can be a part of (e.g., ticks biting us, microorganisms in our intestines, having pets) and ask students to classify them as parasitism, mutualism, or commensalism. Then have students practice by thinking of one more example of each kind of symbiosis.
    • Students can complete the Fan-N-Pick Kagan Cooperative Learning Structure verbal activity. Give students index cards with vocabulary terms and/or ecology phrases. Working in small groups, have students pick a card and define the word or phrase on the index card.

    o   Fan-N-Pick (an activity for teambuilding, mastery, thinking, communication): Students play a card game to respond to questions.

    1.   Student 1 holds the question cards in a fan and says, “Pick a card, any card!”

    2.   Student 2 picks a card, reads the question out loud, and allows five seconds of think time.

    3.   Student 3 answers the question.

    4.   Student 4 restates the answer.

    a.  For right or wrong answers, Student 4 checks if correct and then either praises or coaches.

    b.  For a higher-level thinking activity when questions have no right or wrong answers, Student 4 does not check for correctness, but praises and paraphrases the thinking that went into the answer.

    5.   Students rotate roles clockwise for each new round.

    Source: http://edweb.sdsu.edu/People/tkopcha/fall2007/mathed502/kagan_strats.pdf

     

    • Students who might be going beyond the standards can investigate how probiotics in foods such as yogurt may improve human health. Have students prepare a one-minute advertisement for a new food product with probiotics and present it to the class. Suggested Web sites:

    o   http://en.wikipedia.org/wiki/Probiotic

    o   www.mayoclinic.com/health/probiotics/AN00389

Related Instructional Videos

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DRAFT 05/12/2011
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