The Grass Is Always Greener

Ecocolumn Design Biology COE Classroom Practice Task

Description: Students design a model ecosystem that can sustain itself.

Item Description (Performance Expectation statement from the Biology EOC Item 2009 WA Science Std Specifications) & P.E. Evaluate the solution(s) with respect to criteria on which to judge success and/or constraints (i.e., 1a limitations) on the solution(s) given one or more solution(s) to a problem that can be solved using a APP-C(1) technological design process. Describe a method for testing the solution(s) given a problem that can be solved using a technological 1b APP-C(2) design process and possible solution(s). Describe criteria that would be used to evaluate potential solutions and/or describe constraints (i.e., 1c limitations) on potential solutions given a description of a problem that can be solved using a APP-B(1) technological design process. Describe the cycle of carbon through ecosystems (e.g., carbon dioxide in air becomes large carbon- containing molecules in the tissues of plants through photosynthesis, these molecules can be cycled to 2a LS2 – A(1) animals that consume the plants, then returned as carbon dioxide to the atmosphere through cellular respiration, combustion, and decomposition). Describe the cycle of nitrogen through ecosystems (e.g., nitrogen in air is taken in by bacteria in soil, 2b then made directly available to plants through the soil, and returned to the soil and atmosphere when LS2 – A(3) the plants decompose). Describe conditions necessary for populations to increase rapidly (e.g., adequate living and nonliving 3 LS2-B(1) resources, no disease or predators). Describe a plan to answer a given question for a controlled experiment with the following attributes:  At least two controlled variables  One manipulated (independent) variable with three or more conditions  One responding (dependent) variable 4 INQ-B(1)  Experimental control condition, when appropriate  Additional validity measure  Data to be gathered and recorded from multiple trials  Logical steps Describe a redesign of a solution given a solution to a technological design problem and the results of 5 APP-C(3) a test of that solution.

Biology COE Classroom Task – Developed by Bethel School District, October 2013 Ecocolumn Design Sarah and Maliq are competing to design a compact ecosystem that sustains itself a long time, with minimal maintenance required. Here is the ecosystem design problem and the criteria for judging success of the design.

Problem: Design a low-maintenance ecosystem. It should sustain the living things for a long time, and should require as little maintenance as possible.

Criteria for judging success of the ecocolumn design: 1. The populations in the ecocolumn should survive a long time, and should require very little maintenance. 2. The ecocolumn should be closed, with housing is constructed primarily with empty 2-liter soft drink bottles. 3. The starting ecocolumn must contain no more than 10g soil. 4. The ecocolumn system must contain at least: a. 2g Kentucky Bluegrass seeds (Poa pratensis) b. 3g House Crickets (Acheta domesticus) c. 5g Apple Snails (Pomacea diffusa) 5. Additional animals and plants may be included.

Needs of Organisms

Aquatic: low-quality water OK (pH 7 or more). Fresh air. Omnivorous (vegetables, brine shrimp, Apple Snails other snails). Excess food bad for water. Temperature 18-28°C. Ventilation (but can escape). Omnivorous (oats, fresh fruit/ vegetables, grass, carnivorous if not fed). House Crickets Change dirty water. 16hrs light. Temperature 20-30°C. Kentucky Sunlight. Soil: loose (for air & roots), rich (nutrients), absorbent (water), pH 6.5-7. Water heavy, Bluegrass then dry a little (roots grow down). Threats: weeds, disease, bugs.

Controlled soil temperature (13-25°C), moisture (for skin to breathe), air circulation (to flush CO2), Redworms and pH (4-8 OK, 7 is best); crushed egg shells can help). Prefer soil with plenty of organic matter (eats fruit/vegetable/paper scraps).

Two Ecosystem Designs Plan A Plan B # Chambers Three chambers One chamber 3g in upper chamber Soil 10g soil 7g in middle chamber Water 800ml in bottom chamber (see maintenance) Bluegrass 2g seeds in middle chamber soil 4g seeds in soil Crickets 6g in middle chamber 3g Snails 10g snails in bottom chamber 5g Redworms 5g worms in upper chamber soil 5g in soil 5g food scraps in upper chamber soil 15g food scraps mixed into the soil Food 2g vegetables in middle chamber 10g vegetables on top of soil, near sides of 3g vegetables in bottom chamber chamber Add food each week – same as above. Maintenance Add water as needed to keep soil moist. Add water as needed to keep soil moist.

Biology COE Classroom Task – Developed by Bethel School District, October 2013 1 a) Compare Plan A to Plan B, using the criteria for judging the success of the ecocolumn design. APP-C1

Which plan will be more successful, according to the criteria? (Plan A or Plan B)

Describe two criteria that you are using to decide which plan will be more successful.

First criterion:

Second (different) criterion:

Describe a way that the plan you chose will be more successful in each of the criteria you described. First criterion:

Second (different) criterion:

1 b) Describe a way to test the two plans, to show which plan is more successful according to the criteria. APP-C2

Test Procedure:

Biology COE Classroom Task – Developed by Bethel School District, October 2013 APP-B1 1 c) Predict two constraints that could limit the success of Plan A.

Describe one constraint for Plan A:

Describe how this constraint could limit the success of Plan A.

Describe a different constraint for Plan A:

Describe how this constraint could limit the success of Plan A.

Biology COE Classroom Task – Developed by Bethel School District, October 2013 2 a) Describe a path of carbon through the ecocolumn, beginning and ending with carbon dioxide in the air. Include the air in the ecocolumn and two different organisms in the path of carbon. LS2-A(1) In your description, be sure to:  Begin and end with carbon in the air of the ecocolumn.  Identify the molecule that contains the carbon for each step in the path.  Describe the roles of the two organisms in the carbon cycle.

You may use words and/or labeled diagrams in your answer.

Biology COE Classroom Task – Developed by Bethel School District, October 2013 2 b) Describe a path of nitrogen through the ecocolumn, beginning with nitrogen in the air and ending with nitrogen incorporated into a cell structure in an organism in the ecocolumn. LS2-A(3) In your description, be sure to:  Begin with nitrogen in the air of the ecocolumn.  Identify the molecule that contains the nitrogen for each step in the path. You may use words and/or labeled diagrams in your answer.

Biology COE Classroom Task – Developed by Bethel School District, October 2013 3 If a water plant were introduced into the aquatic habitat of Plan A, how might this lead to a change in one of the populations in the ecocolumn in the next month? LS2-B(1) In your description, be sure to:  Describe a change to one of the populations in the ecocolumn (other than the water plant itself).  Explain how the new water plant leads to this change.

Biology COE Classroom Task – Developed by Bethel School District, October 2013 4 Write a plan for a new controlled experiment to answer the question in the box. You may use any materials and equipment in your procedure: INQ-B(1) Be sure your procedure includes:  logical steps to do the experiment  one responding (dependent) variable  two controlled (kept the same) variables  how often measurements should be taken  one manipulated (independent) and recorded variable Controlled Experiment Question: What is the effect of the number of grass plants on the number of crickets surviving after 4 months? Procedure:

Biology COE Classroom Task – Developed by Bethel School District, October 2013 APP-C(3) Sarah and Maliq decided that the design of Plan A was not working for the middle chamber, because the number of crickets declined after 8 weeks. They decided to improve the design of their ecocolumn so that the cricket population would increase. Of course, also want to maintain the other populations in the ecocolumn. Describe two changes you could make to Plan A (other than adding more food) that would increase the cricket population and still maintain the other populations. In your redesign, be sure to:

 Describe two changes in the design of ecocolumn Plan A.  Explain how your each change would be better for the crickets than the original system/solution, but would still be good for the other populations. Describe one change in the design of ecocolumn Plan A (other than adding more food).

Explain how this change will lead to increase in cricket population, but would still be good for the other populations.

Describe a different change in the design of ecocolumn Plan A (other than adding more food).

Explain how this change will lead to increase in cricket population, but would still be good for the other populations.

Biology COE Classroom Task – Developed by Bethel School District, October 2013