Module 2: Ecology

Essential questionsHow does matter and energy move through an ecosystem? (3.4, 3.5, & 4.1)How is food used by a cell for energy and structure?What factors limit the amount of life an ecosystem supports? (4.1)What if one such factor is suddenly too abundant or totally missing?What are some ways humans and natural phenomenon impact ecosystems? (4.2)What impact do invasive species have in ecosystem stability? (4.3)What factors affect an ecosystem’s stability and what is their impact? (4.4)How do ecosystems respond to disturbance?

Student Learning Objectives*In order to answer the above essential questions, students should be able to:

1. Create a food web to analyze the importance of each organism within the web. 2. Describe the human impact on natural resources and an ecosystem.3. Interpret ecological pyramids from data.4. Explain the effect of limiting factors on population growth.5. Describe the pattern of succession that follows an environmental disturbance.6. Define and describe the interactions between species and their affect on the stability

of an ecosystem.7. Evaluate the effect of non-native/invasive species on the stability of an ecosystem.8. Explain the biogeochemical cycles and their role in ecosystems.

Indiana Standards3.4: Describe how matter cycles through an ecosystem by way of food chains and food webs and how organisms convert that matter into a variety of organic molecules to be used in part in their own cellular structures.3.5: Describe how energy from the sun flows through an ecosystem by way of food chains and food webs and how only a small portion of that energy is used by individual organisms while the majority is lost as heat. 4.1: Explain that the amount of life environments can support is limited by the available energy, water, oxygen and minerals and by the ability of ecosystems to recycle the remains of dead organisms. 4.2: Describe how human activities and natural phenomena can change the flow and of matter and energy in an ecosystem and how those changes impact other species. 4.3: Describe the consequences of introducing non-native species into an ecosystem and identify the impact it may have on that ecosystem. 4.4: Describe how climate, the pattern of matter and energy flow, the birth and death of new organisms, and the interaction between those organisms contribute to the long-term stability of an ecosystem.

Essential vocabularyautotrophheterotrophproducerprimary consumersecondary consumerherbivorecarnivoreomnivorescavengerdetritivoreclimate

population communityecosystemspeciespredatorpreyfood webfood chainbiomassfood pyramidbioticenergy pyramid

commensalismsparasitismmutualismsymbiosisprimary successionsecondary successionpioneer species biomesabioticdisturbanceinvasive species

exponential growthcarrying capacitytolerancelimiting factorsnichecompetitionbiosphereclimax communitylogistic growth

Sequence Timing ~18 - 21 days (timing is based on 55-minute periods)This sequence does not include any time for quizzes and review. However, a test has been provided and other formal assessments can be created based on classroom need. Also, you are strongly encouraged to incorporate one of the Vernier labs listed at the end of this module.

1. Paradigm Activity - Human Water Connection – WB and discuss (2-3 days)

2. Model Deployment - Alien Pyramid – WB and discuss (1 day)

3. Oh Deer Game, Wolf Limiting Factors, OR A Predator -Prey Simulation (1-2 days)

4. Pond Succession pictures (½day)

5. Successful Succession Activity (1½ days)

6. Biome Research Project (? days)

7. Symbiotic Strategies Activity (4 days)

8. Local invasive species activity or presentation (2 days)

9. Human Footprint Activity (3 days)

10. Cycles activities – WB and discuss. (2 – 3 days)

11. Post - Module Assessment – Test

Instructional Notes:*These activities can be modified to suite your classroom needs.

*This sequence does not include any time for quizzes and review, Also, you are strongly encouraged to incorporate one of the Vernier labs listed at the end of this module.

Energy Transfer:1. Paradigm Activity – Human Water Connection

(Adapted from the Lake County Forest Preserve District, Lesson 15)*This activity targets Learning Objective 1, 2, 6, & 7

MaterialsLake Michigan Species Cards (found in the Ecology file folder for Human-Water

Connection)Paper arrows (at least two sets per group) Water Pollution Overview (for teachers)Water Pollution Overview reproducible for studentsHuman Activity Scenario Cards Additional Notes with Scenario G and Food chains descriptionInformation about various types of pollution available in the textbook or the Internet     

Day 1Pre-activity discussion

1. Water has an impact on human activity; human activity has an impact on water.2. Ask students to share their responses to the statement above on whiteboards.3. When sharing the boards, as a class, brainstorm ways that humans pollute the

water (i.e., sediment, toxic, bacterial, and nutrient pollution). 

Instructions1. Divide the class into groups and assign each group a type of pollution to

investigate.2. Using the Internet and books, each group will prepare a short 3-5 minute

presentation for the class about their topic. Each presentation should include the following:

• Definition of the chosen type of pollution • Cause(s) of the chosen type of pollution • Prevention of the chosen type of pollution• Handout for other students summarizing the information (Before their

presentation, students should make enough copies for everyone in the class.)3. Before the presentations, distribute one blank Water Pollution Overview

reproducible to each student. Instruct students to take notes on this reproducible during each presentation.

 Post-activity discussion

1. During the presentations be sure to ask students to think of the effect Humans have on the environment.

2. Be sure to review their Pollution overview sheets for accuracy.3. Review each type of pollution and ask for examples.

4. Pollution and the Lake Michigan Food Web Day 2

Pre-activity discussion1. Review the concept of a food chain with students and have them recreate a food

chain on the white boards and share out as a group. Make sure students have a working knowledge of the following terms: food chain, ecosystem, producer, consumer, herbivore, carnivore, omnivore.

2. Arrange the students in groups.  Pass out the species cards and arrows to each group. Ask the groups to use the information on the cards to recreate a food chain on the whiteboard.  Then have a share out of all the different chains the students created.  Discuss how these things can all interact.

Instructions1. Each group will create a food web using the species cards (representing

organisms in the web) and arrows (representing the flow of energy). Walk around while students are working to make sure they are on the right track. *Note: One common mistake students make is placing the arrows in the wrong direction. Remind them that the arrows point in the direction of energy flow — producer consumer, not the other way around!

2. Once the groups have completed their webs, pass out the Human Activity Scenario Cards. Each group should receive a different card. Students should read the scenario cards and determine how this human activity will contribute to water pollution, and as a result affect their food webs.

3. Students should rearrange their webs to show how the introduction of the pollution affects the environment. *For example, an increase in nutrients might cause an algal bloom, followed by a decrease in consumers due to lack of oxygen.

4. Within their groups, they discuss the impact of the varying types of pollution on the different organisms in their food webs. By rearranging the food web, students are able to see the impact of pollution at different levels.

5. Create a whiteboard to present the results of the scenario changes.  Present these to the class. 

6. If time allows, each group can repeat Step 14, using a different card. 

Post-activity discussion1. Over the past several days we have discussed the negative impact that humans

have had on the waters of Lake Michigan. Are there ways that human activity has had a positive impact on the lake? Explain.

2. Reflect on the effect of pollution in the ecosystem.3. What did students notice about the food webs?4. Are all the webs the same?5. Are the scenarios a realistic representation of issues that arise in the

environment?

Extensions

• As a follow-up, students are asked to pick one way that humans have an impact on the lake ecosystem and research possible methods of prevention/treatment.

• Have students pick another ecosystem and create species cards and a food web for that system.

• Ask students to research local, state and federal laws regulating pollution.

Modifications• To shorten this lesson, the following modifications can be made:• Rather than having students do the research themselves, give them handouts or

notes defining types of water pollution.• Save one human activity card aside and use that for the assessment. This

eliminates the time needed for each group to create its own scenario.• To lengthen this lesson, the following modification can be made:• Create more scenario cards for students to practice with before the assessment.

 2. Model Deployment - Alien Pyramid

*This activity targets Learning Objective 3 & 4

MaterialsWhite board and markersStory about the Aliens and tasks

      Pre-activity discussion

1. We use many models to represent various things in life.  It is always easier to see the big picture when it is put in some sort of model/chart.  We get to use our knowledge of a distant planet to create a pyramid of numbers and a pyramid of energy.

2. Discuss how you can measure everything around you.  An ecological pyramid represents the various elements of the environment around you.

3. What happens to the energy that seems to be missing?  Is it really gone? What percent of energy moves from level to level?

Instructions1. Using the Alien Pyramid story as a guide, the students will need to create their

own ecological pyramid on the whiteboards.  2. Once the students have finished you will have a board meeting.   3. Optional: Then give each group a different sample scenario to morph their

pyramids. Then have the groups present their findings individually, explaining the reasoning behind the changes that they have made.

 Post-activity discussion

1. Ask the class how the scenarios are related to a real-life situation.2. Why would you use the pyramid to show this information?3. Why might the numbers not be perfect? (the rule of ten-percent)4. How many trophic levels can an environment support?

 Sample Scenarios:

1. The biologists visiting the planet consume all of the Vorteks or food. 2. A deadly disease wipes out all of the Klukes 3. Animals called Skunkolas travel to the area being studied from another region of

the planet.  The Skunkolas prey upon the Vorteks; the Klukes, however, dislike the taste of Skunkolas and refuse to eat them.

4. More Vorteks are planted. 5. A tertiary consumer called a Joon is introduced.

Populations and Limiting Factors:3. Oh Deer, Wolf Limiting Factors, OR A Predator - Prey Simulation

(Adapted from Project Wild Oh Deer Game)*This activity targets Learning Objective 4 & 6

MaterialsA Predator -Prey Simulation (per team of 2 or 4):

400 small squares (mice) of construction paper (1 cm sqd) 1 larger square (4 cm sqd)masking tapemeter stick

Oh Deer playing field or large gympaper and pencil to record datawhiteboard or chalk board to compile data and graph

Wolf Limiting Factorsplaying field or large gym2 sets of 3 x5 cards: one red, one green

1/3 of each set is labeled “water”1/3 of each set is labeled “food”1/3 of each set is labeled “shelter”

Paper and pencil to record dataWhiteboard or chalkboard to compile data and graph

Pre-activity discussion:1. Discuss the following in pairs, record ideas on whiteboard and share as a class.2. What happens if a population reaches carrying capacity? too small?3. How is a population controlled so the ecosystem remains in balance?

Instructions1. Oh Deer or Wolf Limiting Factors activities are played outdoors or in a large gym.

Oh Deer is recommended for its predator component but if your students did this in middle school, the wolf activity is an alternative that can be adapted to include a predator...humans!

* Cutting out all the mice and owls is extremely tedious, so one teacher asked the severely handicapped classroom if they would like to take on the job and they did a great job!

2. On a rainy day, the Predator-Prey Simulation (Owls and Mice) is suitable for the classroom.

Post-activity discussion1. Students will make a graph on their whiteboard of the data collected during the

activity.2. Locate the discussion and summary questions on each activity to use for closure

discussion.

Succession:4. Pond Succession Pictures

*This activity targets Learning Objective 5

MaterialsPond Succession PowerPointWhiteboards and markersOverhead Projector

Pre-activity discussionThis is the introduction to succession with little to no prior knowledge. 

Instructions1. For this activity students will be in groups of 2-4 students.  They will be shown the

PowerPoint and asked to recreate the pictures in the correct order and give their justification for this arrangement on the Whiteboards. 

2. After about 10-15 minutes the students should have a circle share out of the boards.

Post-activity discussion1. Ask students the reason they placed the pictures in the order they did.2. Are all the arrangements the same?3. What organisms directed you to the order you selected?4. What would you expect to see next?5. Why do you think the pond island with no growth was bare?6. Is the order of regrowth always going to be the same?  Why or why not?7. What is this called? (succession) 8. Introduce primary and secondary succession and then ask what type the pond is

representing.

5. Successful Succession(Adapted from Eastman Outdoors Texas, Successful Succession Curricula)

*This activity targets Learning Objective 5

MaterialsJournalsDigital Cameras

ComputersPowerpoint or KeynoteWorksheets: Cloze Procedure, Flowchart (1 per student)Cards: Forest fire information (4)

Pre-activity discussionNone

Instructions1. Label the 4 corners of your classroom with the following signs:

Strongly Agree, Agree, Strongly Disagree, Disagree2. The teacher should make the statement, “All forest fires are bad.” 3. Students will then go stand in the corner that best represents their feelings about

this statement. Allow students time to share their thoughts in each corner and then have a spokesperson defend each position.

4. Give each group a Forest Fire Information Card to read and discuss. 5. Students will then be allowed to move to a new corner if their views have

changed. Allow them to defend their new choice using specific examples or facts from the cards.

6. Explain to students that there are times when an environment will change drastically and that ecological succession is the orderly replacement of native species over time.

7. Have students use their succession knowledge and flow charts provided to represent the four levels of succession on their white boards. Ask them to predict and draw the plants and animals that will come back in each stage.

Post-activity discussion1. Students will complete the Cloze Procedure Activity on Succession in

pairs. They will use pre-existing knowledge to predict the reasons for and stages of ecological succession. Students whiteboard this

information.2. As a class, go over and discuss the Cloze Procedure Activity and the

whiteboards.  

Biomes:6. Biome Research Project

*This activity targets Learning Objective 1, 2, 6, & 8

MaterialsStudent sheetIndex cards or blank paper

Pre-activity discussion1. Discuss land vs. terrestrial2. Discuss what ‘barriers’ separate biomes / different characteristics biomes are

separated – this would be a good time to use whiteboards.

Instructions:1. Students work independently on their research.

Post-activity discussion1. Students present their finding to the class. Add / Discuss any relevant information

that was missing.

Symbiosis:7. Symbiotic Strategies Activity “Unlikely Travel Companions”

(Adapted from Nature on PBS.org)*This activity targets Learning Objective 1, 2, & 6

MaterialsVideos to be shown to students at the following website:http://www.teachersdomain.org/resource/nat08.living.eco.humeco.lpsymstra/Student Handouts (also on the website)

Pre-activity discussion1. Hold brief discussion about the types of relationships for clarification.

Instructions – See website above

Post-activity discussion1. Whiteboard / brainstorm about man’s impact on the situations in the videos.

Sustainability/Human Interaction/Invasive Species8. Local invasive species activity or presentation

*This activity targets Learning Objective 2 & 7*This model is variable depending on your availabilities in your area.  The best option is to have a local environmentalist visit your school or you can take your students to them.  If you are unable to do this you will need to prepare a presentation about the invasive species in your part of the world.  Students need to see the connection to their world.

 

MaterialsDNR or a local naturalist – Rum Village Park in South Bend Indiana has a wonderful

presentation about Invasive species locally. OR A Presentation about invasive species in your area.

Pre-activity discussion

1. Ask students to whiteboard the plant and animal species they can think of in their neighborhood. Ask how many of these are native to the area.

2. Discuss what a non-native/invasive species is.3. What might be the result of an invasive species in your neighborhood?

 Instructions

1. This is where you should have the presenter or your own presentation about local invasive species.  Here is a site you can use as an example from Ohio. http://www.dnr.state.oh.us/portals/3/invasive/pdf/invasive_plants06.pdf

 Post-activity discussion

1. You can now whiteboard a reflection about the presentation and what types of species are present in your area. 

2. The students can also research possible solutions to the invasive species and then present them to the class at a later time. 

3. They could also help prepare some public awareness events or materials, such as a brochure or poster, to inform others of the issues caused by invasive species, and hopefully help prevent their spread. 

9. National Geographic “Human Footprint Activity” or Monterey Bay Aquarium “Calculate Your Carbon Footprint”

(Adapted from National Geographic Lessons online)*This activity targets Learning Objective 2

Materials (See handouts for materials)

Pre-activity discussion1. Discuss how carbon cycles through the environment.2. Discuss how an excess of CO2 contributes to climate change.

Instructions “Human Footprint Activity” - See website for detailed instructions“Calculate your Carbon Footprint” – See copy of handout

Post-activity discussion1. What is a carbon footprint?2. How would increasing / decreasing your carbon footprint affect our food web?3. What are you willing to do to reduce your carbon footprint? Should the

government try and regulate this? Should there be fines? Other consequences?

Additional “Human Footprint Activity” website: http://channel.nationalgeographic.com/channel/human-footprint/consumption-interactive.html

Cycles of Carbon, Nitrogen, Phosphorus and Water10. Nitrogen Cycle Game

http://spark.ucar.edu/activity/nitrogen-cycle-game*This activity targets Learning Objective 8

MaterialsReservoir Station Signs11 dice11 different rubber stamps and ink pads or Stamp Templates and glue sticksPassport Worksheets for each student (found on the following website) https://spark.ucar.edu/sites/default/files/images/activity/Nitrogen_passport_worksheet.pdf

Pens or pencilsPaper

Pre-Activity Prep:1. Print Reservoir Station Signs2. If using Stamp Templates, print and cut them apart. Store the small stamps in

bags to keep the 11 types separated.3. Copy Passport Worksheets for each student.4. Set up stations around the classroom (or outside). Each station will need a

reservoir sign, a die, plus either an inkpad and rubber stamp, or stamps and a gluestick.

Pre-activity discussion:1. Introduce nitrogen. Where is nitrogen found on Earth? Why is it important?

Explain that nitrogen travels with the help of bacteria, water, lightning, plants, and animals.

2. Show the nitrogen reservoir signs around the room and explain that these are the places to which nitrogen can travel. These places are called reservoirs.

3. Tell students that for this activity they are each playing the role of a nitrogen atom. They will travel through the nitrogen cycle (i.e., to different stations around the room) based on dice rolls. Tell students that they will each carry a nitrogen passport with them and stamp it (or paste a stamp in it) each time they get to a nitrogen reservoir station. They will then toss the die at the reservoir to determine their next destination. Remind students to note in their passport how they get from one place to another based the roll of the die.

4. Spread students so that there are a few at each station and allow them to start traveling with their passport.

Instructions:1. Refer to website for complete instructions to finish this activity including printable

station directions and student follow along handout.

Post-activity discussion:1. How many stops can you make on your trip?2. Will your journey ever end?3. Was everyone’s journey the same? Why not?

4. What would happen if a farmer used too much fertilizer? (In this game, that would mean that everyone starts from the fertilizer station at the same time.)

5. What would happen if we burnt too many fossil fuels?6. Livestock farming creates a large amount of animal waste. How would this affect

the nitrogen cycle?

11. Water – “Blue Planet” and “Incredible Journey” NEED HANDOUTS FOR THIS

*This activity targets Learning Objective 8

MaterialsIntro Activity:

Sets of 200 beads; 58 yellow, 142 blueWhite Boards

Main Activity:See handouts for “Incredible Journey”

Pre-Activity Prep1. Assemble Dice2. Set up stations with sign, dice, and beads

Pre-Activity Discussion1. How much of the planet do you think is water? (Have students write down their

estimates on their whiteboard.)

Instructions1. One person per group will be pulling out beads, one at a time, while the others

keep track of which color and how many are pulled. The student pulling beads should return the bead to the container after each pull.

2. Students find percentages (out of 30) for the first trial.3. Each group will repeat step 1. Groups will again find percentages but combine

the two trials to find a percentage out of 60.4. Discuss the importance of sample size and performing multiple trials. Also,

discuss the ratios of water vs. land on earth.5. For the main activity, students report to a station that has been set up in an open

space. *Consider allowing students to keep the string as a bracelet or key chain. If this is an option you choose, you may prefer to use more durable materials.

6. For remaining directions, refer to the handouts for “Incredible Journey”.

Post-Activity Discussion1. At teacher discretion.

Additional Activities:

Mr. Parr’s Biome Song (video)

MaterialsMr. Parr Biome Song (found on YouTube http://www.youtube.com/watch?

v=0A5eeE93uEA )Whiteboards and markersAdditional research materials- textbooks or the internet with information about Biomes

 Pre-activity discussion

1. Ask students what they know about Biomes. 

Instructions1.This activity is a brief overview of Biomes.  It is important for students to know

about the different Biomes around the world so that they are able to relate the flow of energy through various places and to understand how climates are variable around the world. 

2. You should show the Mr. Parr video to the class.  They may want to see it a second time a little later. 

3. After this you will divide the class into groups of 2-4 students and they will each select a different Biome to study. 

4. For the next 30 minutes students should prepare a brief presentation about their Biome on a whiteboard. 

5. You will then present these to the class one at a time.  During the presentations be sure to have students elaborate on the types of organisms that are present, the climate, precipitation, and locations on Earth.

 Post-activity discussion

1. Ask students what types of things were the distinguishing characteristics of a Biome.             

2. What happens to the organisms that die in each of the Biomes?3. What type of cycles are you able to think of occurring in the Biomes and do they

vary in different places?4. What would happen if an organism from one location moved into another?  What

if it is a non-native species?5. Mention that species/biomes are migrating north.  Why do you think this might be

happening? What could have happened in the past? (Pangea)

Videos and songs about Nutrient Cycles*This activity targets Learning Objective 8

Materials:Youtube nutrient cycle songs

videos on nutrient cyclesballoonsconstruction or bulletin board paper

yarnmarkerstapeother craft materials4 whiteboards per team

Pre-activity discussion:Ask students what is meant by “You are what you eat” or ask what they need to grow. Have them whiteboard their ideas.Elicit from them that they need more than energy...they need materials.Ask what materials they need to build a living thing.Ask where their food acquires these materials.Ask students why nutrients have to be recycled, but energy can get used up.Show videos and/or songs on the cycles to introduce the topic. Suggested media are in the appendix

Instructions1. Place on each wall of your classroom the following signs or images:

OceanAtmosphereSoil/rocksForest

2. Assign teams of students to act out one of each of the nutrient cycles.(If you have need of a fifth group, you may want to consider having one team act out a food web to contrast the flow of energy and the cycling of nutrients). 3. Provide time to design their “skit”, assign roles, make costumes or props and rehearse.4. Have teams make one whiteboard of their cycle.5. Teams present their skits.

Post-activity discussion

1. While each team presents, have the other teams make one whiteboard of the cycle being presented. At the end of the skits, teams convene into board meetings to compare their boards to textbook versions. Record and repair any discrepancies. 2. Hold a whole class board meeting and elicit the key processes of each cycle, where the reservoirs are, the role of decomposers, and human impact.

The following are songs and videos to review or introduce the cycles:

Mr. Parr’s Water Cycle: http://www.youtube.com/watch?v=o3BVa7PH_JECarbon Cycle song: http://www.bing.com/videos/search?q=+%22carbon+cycle%22+Songs&view=detail&mid=71CCF66DC0BEAE5A5A4071CCF66DC0BEAE5A5A40&first=0

Vernier Primary Productivity Lab (2 days)Vernier Population Dynamics Lab (1 full day to set-up, 8 days for observations (15-20 min/day)Vernier Biodiversity Lab (1 day) (can be done without Vernier equipment)Vernier Acid Rain Lab (1 day)Vernier Interdependence of Plants and Animals Lab (2 days)

Below are samples of the instructional notes for two Vernier labs.

Model Vernier Primary Productivity: 2 daysMaterials

Data collection hand-held LabQuest DevicesDissolved oxygen probesBottles or tubes that can form airtight sealsPond water or a source of Chlorella: 5 ml of Chlorella per liter of waterPlastic window screen from hardware store: 17 12cmx12cm piecesDispense water easily using a carboy with a spout at the bottom and a

tube on the spout and a shallow pan to catch dripsFlorescent light to direct onto filled tubes laid horizontally on a table

Pre-activity discussion What do producers produce? (Elicit from past knowledge food and oxygen) How can we measure the amount of photosynthesis (productivity)? Introduce Vernier probes

InstructionsFirst part of lab can be done while on a field tripFollow directions on “cookbook” lab but use “questioning” to guide the thinking of students as the lab proceeds.Students prepare data table, graph and conclusion on whiteboardsHold a board meeting.

Post-activity discussion Ask students to relate lab results to Energy Pyramids and food webs. Discuss what factors limit or increase productivity Discuss how this would affect the shape of the pyramid or food web

Model: Vernier Population Dynamics: 1 full day to set-up, 8 days for observations (15-20 min/day)Materials

Photo of yeast under a microscopeData collection hand-held LabQuest DevicesVernier Colorimeter

18x150 test tubesCuvette and lid2 5-ml pipettes or 10 ml graduated cylindersdropper pipetteglass marking pencilsgraph papermicroscope, slide, coversliptest-tube rackcotton swabs

Pre-activity discussion Give students their closed system of a yeast population with food. Show them the picture of yeast under a microscope. On their whiteboards have students answer the following questions. How could we determine the density of the yeast population? How might the yeast population change over time? What factors would determine the rate of change in their population?

Instructions Ask what aspects of populations might be measured. Elicit density. Ask how we could observe a yeast population. Elicit microscope. Elicit that one could count yeast per area under a scope. Introduce a colorimeter means of measuring density using turbidity.

Post-activity discussion Students will whiteboard data tables, graphs and their conclusions. Class will

hold a board meeting to share, make observations, and the main point of the lab.

Additional Resources: Here are some additional resources for videos. Feel free to show these whenever

you find them appropriate throughout the module. The video called “How Ecosystems Work” is appropriate for Energy and nutrient cycles.

http://www.youtube.com/profile?user=greatpacificmedia&src_vid=o_RBHfjZsUQ&feature=iv&annotation_id=annotation_753252#grid/user/8F2AF6D5E617BA4B

Misconceptions

• Stronger organisms have more energy.

• There are more herbivores because they have more offspring.

• A species high on the food web is a predator to everything below it.

• Energy accumulates in an ecosystem so that a top predator has all the energy from

the organisms below it.

• Carnivores can exist in a plant free world if their prey reproduces enough.

• There is a starting and ending point in the food chain.

• The simpler the organism, the simpler the food it eats. Therefore, as an organism

increases in complexity the more complex the food it eats.

• Energy only flows from the top of the food chain down, with those at the top having the

most energy and increasing in number at the expense of those below.

• Energy flow is one-way, rather than cyclical or two-way.

• Organisms in a population are important only to those other organisms on which it

preys for food sources.

• A population located higher on a given food chain within a food web is predator of all

populations located below it in the chain.

• Producers in a community are the most numerous because energy in a food chain

goes on diminishing and less energy passes to each animal. It is wasted in respiration

and growth.

• A size change in one population will have not too much effect over another population

of the same food web because the chains are spread out.

• In a food web, a size change in one population will only affect another population if two

populations are directly related as predator-prey.

• Populations will increase indefinitely because the resources are unlimited.

• There is no link between fluctuations in population size and environmental issues like

food supply.

• Chemical pollutants undergo no change in form as they move through food chains.

• The food that is eaten and used as a source of energy is part of the food chain; food

that is synthesized into the body of the eater is now food for the next level.

• Energy is not conserved.

• Students believe energy can be recycled through an ecosystem many times

• Plants obtain their energy directly from the sun.

• Plants have multiple sources of food (heterotrophic as well as autotrophic).