Popcorn Energy Flow Lab

Objective:In this lab we will create a model of energy flow through an ecological system. We will use popcorn and various containers to represent energy flow through each trophic level. You will need paper and a calculator. You will get lots of practice converting to metric, within metric and calculating percentages.

Materials:

  • One bag of ready to eat popcorn per group
  • A variety of containers to represent trophic levels
  • Electronic balances
  • Table spray and napkins
  • Calculators

Procedure:

  1. You will need to work in groups of 2 or 3.
  2. You may choose your own groupsbut choosewisely! There will be much opportunity for distraction!
  3. Each group should have a leader,sweeper, and measurer.
  4. Predict what your energy pyramid will look like and what type of organisms would be at each level. Write your prediction down.
  5. Obtain 1 bag of popcorn from the Energy Supply area. Be sure to note special information onthe bag (i.e. mass or volume). This information may prove useful when you need to performcalculations.
  6. DO NOT THROW THE BAG AWAY! It has useful information on it that you will use to determine the amount of calories and popcorn that move to the next level.
  7. You need to show your calculations.
  8. Hints: Don’t get frustrated there is no one formula for success and don’t forget you need to mass only for the energy and not the container they have on the balance. So,remind them to subtract the container weight.
  9. Select containers from the materials that you will build your model of energy flow.
  10. create a model of energy flow using your materials based on your calculations
  11. You must write up your detailed proceduresuch that another scientist could replicate your model. This means each step needs to bejustified and explained thoroughly.
  12. Special hint--‐--‐--‐remember only 10% of energy that enters a system makes it to the next trophiclevel.
  13. You need to be able to quantify (number value) the amount of energy that leaves a system as waste andmakes it to the next trophic level. This is where the balances and calculator come in.
  14. When you are satisfied your model, you will need to show it to me, and walk me through it as if Iwere your student. Once approved you will take a picture of your diagram.
  15. Each group will submit a complete lab write – up due 4/12 by the end of the day (3:15).

Data:

  1. Research a method to determine the amount of calories you have been given; converting grams to calories for fat, carbohydrates, etc. You will need to use the information from your popcorn bag.
  2. Write the formula; then calculate.
  3. How much energy is “available” at the top of the pyramid?
  4. Picture of 3D model as well as drawn model with labels (calories, primary producer, etc), your levels will be dependent on the amount of energy left.

Discussion: (answer in complete sentences in your journal)

  1. Provide a brief summary of what happened during your lab experiment and your findings. What or who in an ecosystem is represented for each level of your energy pyramid?
  2. Why does only 10% make it fromone level to the next?
  3. Why is there seldom more than 4 trophic levels?
  4. Discuss how you know that your energy model is representative of energy flow in nature.
  5. How does the role of plants and other photosynthetic organisms impact the survival of consumers?
  6. How does man/our society” interrupt”Earth’s energy flow?
  7. What sustainable plans are being implemented to improve the integrity of the Earth’s food webs.
  8. Why is a pyramid used to represent the trophic levels?
  9. What would happen if the pyramid was flipped?
  10. What other benefit do plants provide us?
  11. How does the complexity of a food web allow for the survival of a species?