Lesson Plan

Relationships among Organisms

  • Grade Levels
    8th Grade
  • Related Academic Standards
  • Assessment Anchors
  • Eligible Content
  • Big Ideas
    • A technological world requires that humans develop capabilities to solve technological challenges and improve products for the way we live.
    • An object’s motion is the result of all forces acting on it.
    • Each area of technology has a set of characteristics that separates it from others; however, many areas overlap in order to meet human needs and wants.
    • Energy is neither created nor destroyed. Energy can be transformed from one form to another, but transformation between forms often results in the loss of useable energy through the production of heat.
    • Solid, liquid and gaseous earth materials all circulate in large scale systems at a variety of time scales, giving rise to landscapes, the rock cycle, ocean currents, weather, and climate.
    • Technological design is a creative process that anyone can do which may result in new inventions and innovations.
    • Technological literacy is the ability to use, assess and manage technology around us.
    • Technology is created, used and modified by humans.
    • The cell is the basic unit of structure and function for all living things.
  • Concepts
    • A technological design & problem solving process changes ideas into a final product or system.
    • All living things are made up of smaller units called cells.
    • All multicellular organisms have systems that interact with one another to perform specific functions and enable the organism to function as a whole.
    • An object will stay at rest or continue at a constant velocity unless acted upon by an external, unbalanced force.
    • Batteries store chemical energy and transform it into electrical energy.
    • Bio-related technologies are the processes of using biological mater to make or modify products.
    • Bio-related technologies are the processes of using biological organisms to make or modify products.
    • Cells carry out the many functions needed to sustain life.
    • Cells grow and divide thereby producing more cells.
    • Cells take in nutrients that they use to provide energy to carry out their life functions.
    • Communication is the process of composing, sending, and receiving messages through technology.
    • Communication is the process of composing, sending, and receiving messages using technological devices.
    • Construction is the process of turning materials into useful structures.
    • Construction is the process of turning raw materials into useful structures.
    • Decisions about the use of products and systems can result in expected and unexpected consequences.
    • Different body tissues and organs are made up of different kinds of cells.
    • Disease affects the structures and/or functions of an organism.
    • Earth materials (rocks and soils) can be classified by their composition and texture and those features can be interpreted to infer the history of the material.
    • Energy and power technologies are the processes of converting energy sources into useful power.
    • Energy and power technologies use processes to convert energy into power.
    • Energy appears in different forms and can be transformed within a system.
    • Energy can be transformed within a system or transferred from one system to another (or from a system to its environment) in different ways. Thermal energy is transferred from warmer objects to cooler objects. Mechanical energy can be transferred when two objects push or pull on one another. Electromagnetic energy can be transferred when an electrical source such as a battery or generator is connected in a complete circuit to an electrical device. Chemical energy is transferred when particles are rearranged in a chemical reaction.
    • Energy from the sun warms air and water, which creates moving currents within them. This movement causes changes on the earth’s surface.
    • Every organism has a set of genetic instructions that determines its inherited traits.
    • Everything on or near the earth is pulled toward Earth’s center by a gravitational force. Celestial revolutions are caused by gravitational attraction.
    • Friction is an example of an electromagnetic force that opposes motion between two surfaces.
    • Heat energy is usually a by-product of an energy transformation.
    • Heat flow from the earth and motion within the earth lead the outer shell of the earth to move around in large rigid pieces (plates) and leads to the creation and destruction of ocean basins, motion of continents relative to one another, earthquakes, volcanic eruptions, and development of mountain belts.
    • Heat moves in predictable ways, normally flowing from warmer objects to cooler ones, until the objects reach the same temperature.
    • Human activities change land cover and land use patterns, add or remove nutrients from ecosystems and modify some of the fundamental cycles of the earth system, including the carbon cycle. These changes can have unexpected and far-reaching effects due to the complex interconnections among earth systems.
    • In a technological world, inventions and innovations must be carefully assessed by individuals and society as a whole.
    • Innovation is the process of improving an existing product, process, or system.
    • Innovation is the process of modifying an existing product, process, or system to improve it.
    • Interaction of circulating air masses gives rise to a wide variety of weather phenomena including fronts, mid-latitude cyclones (and anti-cyclones), and severe weather (tropical storms, tornados, severe thunderstorms, etc.).
    • Invention is a process of creating new products, processes, or systems.
    • Invention is a process of turning ideas and imagination into new products, processes, or systems.
    • Inventions and innovations must be carefully assessed by individuals and society.
    • Large scale wind patterns drive surface currents in the oceans and affects weather.
    • Manufacturing is the process of turning materials into useful products.
    • Manufacturing is the process of turning raw materials into useful products.
    • Mass is a measure of the amount of matter in an object.
    • Mechanical advantage, using less force over a greater distance, allows the same work to be performed with less effort.
    • Models (graphs) of an object’s velocity versus time can be used to infer the presence of absence of unbalanced forces.
    • Moving electric charges produce magnetic forces and moving magnets produce electric forces.
    • People select, create, and use technology.
    • Plants transform light energy into chemical energy, which then can be used by other living things.
    • Safety is a preeminent concern for all technological development and use.
    • Safety is one of the most important concerns for all technological development and use.
    • Science and technology are interconnected.
    • Simple machines help accomplish a task with less effort by either changing the direction of motion or increasing the mechanical advantage.
    • Some changes in Earth’s surface are abrupt, such as earthquakes, volcanoes, meteor impacts, and landslides. Others are gradual, such as the lifting up of mountains or their wearing away by erosion.
    • Some organisms are made up of only one cell.
    • Specialized cells perform specialized functions in multicellular organisms.
    • Technological design & problem solving follows many steps.
    • Technological design & problem solving includes both formative and summative analysis.
    • Technological design & problem solving includes clearly communicated solutions.
    • Technological design & problem solving includes frequent checking.
    • Technological design & problem solving requires hands-on applications.
    • Technological design & problem solving requires the ability to clearly communicate engineered solutions.
    • Technological design & problem solving requires the application of hands-on abilities such as sketching, prototyping, and fabricating.
    • Technological design & problem solving transforms an idea into a final product or system.
    • Technological design & problem solving utilizes a series of steps that take place in a well-defined sequence.
    • Technological literacy is necessary for a productive workforce.
    • Technological literacy is necessary for all citizens.
    • Technological literacy is the ability to understand, use, assess, design, and create technology.
    • Technological literacy requires lifelong learning.
    • Technology and society impact each other.
    • The abilities required in a technological world include diagnosing, troubleshooting, analyzing and maintaining systems.
    • The abilities required in a technological world include understanding, fixing, and maintaining systems.
    • The atmosphere circulates in large scale patterns which steer weather systems due to heat from the sun.
    • The circulation of the ocean and atmosphere carries heat energy and has a strong influence on climate around the world.
    • The cycling of water in and out of the atmosphere plays an important role in determining climatic patterns.
    • The Earth is mostly rock, with a metallic core, a thin layer of water covering about ¾ of the surface and surrounded by a thin blanket of air.
    • The Earth’s revolution around the Sun causes the seasons and the year. Because of the Earth’s tilted axis, sunlight falls more intensely on different parts of the earth during different parts of the year, producing the seasons and seasonal patterns in weather.
    • The Earth’s rotation around its tilted axis causes day and night.
    • The gene is the basic unit of inheritance.
    • The goal of technology is to meet human needs and wants.
    • The gravitational force is a universal force that depends on how much mass the objects have and how far apart they are.
    • The magnitude of the gravitational force is weight (oz, lb, newtons).
    • The Moon’s revolution around the earth once in about 28 days changes what part of the moon is lighted by the sun and how much of that part we can see from the earth, giving rise to lunar phases.
    • The rhythms of the Earth are caused by 3 celestial motions: The Earth’s rotation, revolution around the sun, and the Moons’ revolution around the Earth.
    • The sun is the main source of energy for biological systems on the surface of the earth.
    • There are defining structures of cells for both plants and animals.
    • There are structural and functional similarities and differences that characterize diverse living things.
    • There is a relationship between structure and function at all biological levels of organization.
    • Thousands of layers of sedimentary rock confirm the long history of the changing surface of the earth and the changing life forms whose remains are found in successive layers.
    • Transportation is the process of safely and efficiently moving people and products.
    • Two of the fundamental forces that exist in the universe are gravity and electromagnetism.
    • Unbalanced forces acting on an object cause changes in its velocity.
    • Understanding technological systems help us plan and control technological developments.
    • While science is the study of the natural world, technology is the study of the human designed world.
  • Competencies
    • Describe and demonstrate how to use technological design & problem solving.
    • Describe how science and technology work together.
    • Describe how technology impacts society.
    • Describe the flow of energy from the sun, throughout the earth system, living and non-living, from the cellular scale to the global scale, and describe the transformations of that energy as it moves through the system.
    • Describe the relationships among the parts of a system, the ways that they work together, the flow of matter or energy through the system, and the feedback and control mechanism present in the system.
    • Design and develop the ability to create and send messages using technological devices.
    • Design and develop the ability to safely and effectively use tools and materials to build structures.
    • Design and develop the ability to safely and effectively use tools and materials to convert energy into power.
    • Design and develop the ability to safely and effectively use tools and materials to create bio-related products and systems using technology.
    • Design and develop the ability to safely and effectively use tools and materials to create vehicles that transport people and products.
    • Design and develop the ability to safely and effectively use tools and materials to manufacture products.
    • Develop the abilities to use and maintain technological products and systems.
    • Explain how technology has and can change the world.
    • Explain the importance of carefully assessing technological inventions and innovations.
    • Recognize the importance of using technological knowledge in society.
    • Use appropriate technologies to make precise quantitative measurements and observations and to organize and analyze the data.
    • Use design and problem solving skills to solve technological challenges.


In this lesson, students compare various types of relationships among organisms (i.e., biotic interactions). Students will:

  • explain the roles of producers and consumers, and predators and prey in an ecosystem.
  • explain the levels of order in an ecosystem from simple to complex (i.e., individual, community, population, and ecosystem).
  • use evidence to infer the relationship between changes in predator and prey populations.
  • compare symbiotic relationships among organisms (i.e., parasitism, mutualism, commensalism, and amensalism).

Essential Questions


  • Producers: Organisms that use sunlight and/or chemical compounds to produce their own food.
  • Consumers: Organisms that eat other organisms for energy.
  • Species: A group of similar organisms that can breed with one another.
  • Population: A group of individuals of the same species that live in the same area.
  • Community: All of the populations that live together in a certain area.
  • Ecosystem: All of the organisms that live in a certain area and their nonliving environment.
  • Symbiotic: Describes a relationship in which two species live closely together.
  • Predation: An interaction in which one organism kills and feeds on another organism.
  • Parasitism: Symbiotic relationship in which one organism lives in or on another organism (the host) and harms the host.
  • Mutualism: Symbiotic relationship in which both species benefit from the relationship.
  • Commensalism: Symbiotic relationship in which one organism benefits and the other is not helped or harmed.
  • Amensalism: Symbiotic relationship in which one organism harms the growth of another organism, while the organism itself is not affected.
  • Predator: An animal that kills and eats other organisms.
  • Prey: An animal that is killed and eaten by another organism.


75–90 minutes/2 class periods

Prerequisite Skills

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Formative Assessment

  • View
    • While constructing the “Levels of Ecosystem Organization” graphic organizer, orally assess students’ understanding of each level by asking for examples of each level.
    • During the jigsaw activity, circulate around the classroom and assess whether students are able to accurately describe the different species interactions.
    • After the jigsaw activity, collect and grade the Species Interactions Quiz for individual assessment (S-8-9-2_Species Interactions Quiz-Teacher Version.doc).
    • Collect and check the graph and handout for the Predator–Prey Lab Activity.

Suggested Instructional Supports

  • View
    Scaffolding, Active Engagement, Modeling, Explicit Instruction
    W: This lesson focuses on interactions among organisms at the individual and population levels. Students will build on concepts (e.g., producer and consumer) from the first lesson as they examine various kinds of interactions.
    H: At the beginning of the lesson, students activate prior knowledge as they complete the producer/consumer graphic organizer. This also brings the flow of energy in an ecosystem to a personal level as students consider their role as consumers.
    E: Students create a graphic organizer to represent levels of organization in ecosystems. This builds a solid foundation of vocabulary concepts on which to build the jigsaw activity on species interactions and the lab activity on the relationship between predator and prey populations.
    R: Students reflect on their learning in the jigsaw activity as they share out with their home groups. Students revisit the concept of the flow of energy in a food chain as they complete the lab activity and answer the follow-up questions.
    E: Students express their understanding verbally as they do the jigsaw activity, in writing as they take the follow-up quiz, and by creating a graph and analyzing data in the lab activity.
    T: This lesson can by modified by providing students with copies of the written materials for each station of the jigsaw activity. Another alternative is having students work in pairs for the lab activity and create simpler graphs that they share with each other. The lesson can be extended by having students investigate more examples of the various symbiotic relationships or research the reintroduction of predators into ecosystems.
    O: The lesson is organized such that students begin by considering producer-consumer relationships, and then discuss the levels of ecosystem organization. These should be familiar concepts. The lesson builds on this by introducing symbiosis and having students research different species interactions in a jigsaw activity. Finally, students complete a lab activity to investigate how predator and prey populations influence one another over time.

Instructional Procedures

  • View

    Note: Before the lesson, determine five cooperative learning groups for the jigsaw activity in Part 1.

    Part 1

    Have students copy the graphic organizer below into their notes and complete it, placing themselves as the consumers in the center, and three producers that they eat in the other spaces. Call on several students to share their answers, and then briefly review the definitions of producer and consumer from Lesson 1. Add arrows to the diagram to show that energy flows from the producers to the consumer.



    Tell students that there are many different kinds of relationships among organisms in ecosystems. The previous lesson, and this introduction, focused on feeding relationships. In this lesson, we will also examine various “symbiotic relationships,” in which two species live closely together.

    Note: Remind students that a common misconception is that all symbiotic relationships are positive for both organisms. Mutualism, a relationship in which both organisms benefit from the relationship, is one of the many types of symbiosis.

    Explain that first it is important to understand the levels of organization in an ecosystem. Have students copy the following graphic organizer into their notes, and title it “Levels of Ecosystem Organization.”


    Define each term in the graphic organizer above. Elicit examples of each level from students, using a city park as an example for the ecosystem, and have students write down the examples in their notes.

    Species Interactions Jigsaw Activity

    Explain: “Since we have been talking about the various roles that species play in ecosystems, we need to look at how the different species interact with one another, and what roles they play in these interactions.” Tell students that they are going to participate in a jigsaw cooperative learning activity dealing with species interactions. Review the definition of a “symbiotic relationship.”

    Divide students into five groups, and tell them that they are in their home groups. Now distribute Species Interactions Jigsaw Activity–Student Version (S-8-9-2_Species Interactions Jigsaw Activity-Student Version.doc), so students can follow along as you explain to them what they will be doing.

    For this activity each member of the home group will go to one of five stations. At these stations, students will be given materials to read in order to understand a type of species interaction. While at these stations, they will be instructed to read over the definition and example for the interaction (S-8-9-2_Species Interactions Jigsaw Activity-Station Groups Materials.doc).

    After reading the definitions and examples, students should talk with their station group to decide on how to put these definitions into their own words so that they will be able to explain them to their home groups. Have each student take notes on the species interaction because the notes will stay at the station and cannot be taken back to the home groups. Circulate during this time to answer any questions students may have.

    Have each station group brainstorm and come up with at least one other example for the species interaction in order to better explain the term to their home groups.

    After about ten minutes, collect the materials on each species interaction. Send students back to their home groups where they will have around 15 minutes to take turns explaining the species interactions they learned about to the other group members. Encourage students to put ideas into their own words to explain these concepts.

    Have students take notes on what each of the home group members says about their species interaction. Tell them that they will be quizzed after the activity.

    Have students put away their notes to prepare for a short quiz on the activity. Distribute the Species Interactions Quiz (S-8-9-2_Species Interactions Quiz-Student Version.doc), and have students complete it individually.

    Part 2

    Show students the following food chain:

    Grass → Rabbit → Fox

    Ask students to identify the predator and prey relationship in the food chain. Have them predict what would happen to the rabbit population if most of the foxes were hunted and killed. Ask students whether that change could also affect the producers in the food chain.

    Tell students that predator–prey relationships are important in ecosystems because they provide a balance between the populations. Explain that students are going to use some data to investigate a specific predator–prey relationship.

    Distribute the Predator–Prey Lab Activity (S-8-9-2_Predator-Prey Lab Activity-Student Version.doc and S-8-9-2_Predator-Prey Lab Activity-Teacher Version.doc) and have students complete it independently.


    • Students who might need an opportunity for additional learning can complete the Predator–Prey Lab Activity with a partner. Have each partner create a single-line graph (i.e., one for snowshoe hare data, and one for lynx data). Have the partners compare their graphs and work together on the analysis questions.
    • Students who may be going beyond the standards can investigate the reintroduction of lynx in Colorado (S-8-9-2_Colorado Lynx Article.doc) or do an Internet search on “lynx” + “reintroduction.” Have students write an article for an imaginary newspaper on the subject.
    • Have students who may be going beyond the standards conduct a debate or write a persuasive essay on whether hunting should be used for population control of animals such as the white-tailed deer in Pennsylvania.

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DRAFT 05/16/2011
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