A Collaborative EffortA Collaborative Effort

Title: EduWeblabs on Photosynthesis and Lake Profiles Class: Environmental BotanyGrade: 11-12 Timeframe: 3 days

Knowledge Gap Topic What are various locations of niche/habitats/organisms found in streams/watersheds and how are they related to each other?

Subject Matter/Key Vocabulary

Basic equation of photosynthesis related to autotrophs and how that affects gases in streamsRelating CO2 use to growth and O2 production to light intensity and temperature of water

Essential Question/Over-Arching Concept/Key Understanding

Identify the various microhabitats of a stream/lake and relate the physical factors to the biota found in each habitat.

Get a basic idea of how dissolved oxygen relates to temperature of water

Curriculum Connections OGT standards Local standards

Earth Science 9-10: D; 11-12: BLife Science 9-10:D,G; 11-12: E

Performance Objectives/Behavioral Objectives

PO1) Students will be able to describe in everyday terms and chemical equations the processes of photosynthesis and respirationPO2) Students relate various micro-habitats of streams and ponds to these processes and the animals found thereBO1) Students should be able to look at various areas or levels of a stream or pond and be able to determine the basic processes going on there (tropholytic vs. trophogenic zones, etc.)BO2) Students should be able to discuss how man-made products may affect these processes (e.g., phosphorous overloading causing increase in algae)

Materials Handouts: Directions for each of the following three EduWeblabs:1) Elodea Photosynthesis2) Duckweed Growth3) Thermocline Lab

Equipment: Internet connection and subscription to http://eduweblabs.com/Introduction

focus event varies with teacher

Discuss basic food pyramids and the concepts of autotrophs (producers) and heterotrophs (consumers). Introduce basic equations for photosynthesis and respiration and demonstrate that carbon is recycled but energy is not.

Development major parts of unit/

lesson

Labs:1) Do the labs in the order above. In the Elodea lab, plot data and plot a best fit line.2) In the Duckweed lab, change the rates of CO2 and then run a t-test on the results to show a significant change when CO2 levels are increased.3) In the Thermocline lab, plot all the seasons for temperature to demonstrate thermocline occurring mainly in summer and relate

Designing Watershed-based Education and Extension Efforts through a Mental Models Research ApproachUSDA-CSREES National Integrated Water Quality Program

temperatures to oxygen % and where fish might be found. Relate to tropholytic and trophogenic zones and what types of organisms are found in each.

Rigor/Relevance Quadrant(s) link to rigor/relevance

document

A: Must use terms correctly … autotroph, heterotroph, producer, consumer, decomposer, pyramid, photosynthesis, respiration, tropholytic and trophogenic zones, thermocline.B: NoneC: Write equations for photosynthesis and respiration; plot best fit lines relating light intensity and oxygen production; run t tests for significance in oxygen production of plants with varying amounts of CO2

D: Forecast oxygen production with amounts of light not tested. Discuss where autotrophs would most likely be found in a lake and relate to streams.

Product/Artifacts/Student Evidence of Understanding

Graphs which include best fit lines and R squared values

Graphs comparing oxygen production and significance of differences

Diagram of lake profile, locating the following: benthic, limnetic and littoral zones; tropholytic and trophogenic zones

Accommodations plan B differentiated instruction

Establishing good teams that work together well is essential here. It takes two or three people working on different aspects of these labs to put everything together. Important to give reflection time before they turn it in. Perhaps adding some reflective questions at the end relating all concepts would help.

Formative Assessment/Feedback

measure of progress

Use questions during lecture to determine understanding of photosynthesis and respiration equations.

Pop quiz (formative only) on equations

Periodic checks of student data/graphs while doing the EduWeblabsFinal Evaluation

project rubric oral or paper quiz/test portfolio

Students write an essay on the “Carbon Cycle”, illustrating how autotrophs and heterotrophs are intertwined in their use and/or production of CO2 and O2

Student use a best fit line to predict value of oxygen produced when another value of light intensity is used.

Teacher Reflection complete after lesson

Some students struggled with best fit lines … not so much the concept as just the process of using excel to calculate them. It takes some several efforts on the essay to really communicate the cyclical nature of CO2 and O2 being used by auto and heterotrophs. With lower level students relating photosynthesis and respiration to various trophic levels makes sense, but they have a hard time keeping so many different concepts connected. These labs are good as they reinforce each other.

Designers/Email: Fred Donelson (fdonelson@gjps.org)

Additional Comments: These labs help solidify student understanding of photosynthesis and respiration and how they complement each other. The thermocline profile lab helps student relate temperature of water to oxygen content in a lake which can then be related to streams and how oxygen enters streams in different ways. These labs are only available with a subscription to eduweblabs.com.

Designing Watershed-based Education and Extension Efforts through a Mental Models Research ApproachUSDA-CSREES National Integrated Water Quality Program

Photosynthesis EduWeb Lab

Summary:

Students vary light intensity via distance and measure O2 production by autotrophs. Ideas to reinforce are photosynthesis and importance of autotrophs in making oxygen at the base of food pyramid. It also allows kids to plot data, use regression analysis and evaluate lines for best fit and then use best fit lines for predictions.

Designing Watershed-based Education and Extension Efforts through a Mental Models Research ApproachUSDA-CSREES National Integrated Water Quality Program

Duckweed Growth EduWeb Lab

Summary:

Students grow duckweed in both controlled conditions and with extra CO2, showing its importance in photosynthesis. Students use Student’s “t” Test to determine if differences are significant.

Designing Watershed-based Education and Extension Efforts through a Mental Models Research ApproachUSDA-CSREES National Integrated Water Quality Program

Thermocline EduWeb Lab

Relating temperature to dissolved O2 in different seasons

Summary

Students plot temps in different seasons, then predict where fish will be based on their predictions of where oxygen is. Major idea is to help students to realize that water is most dense at 4 degrees Celsius, and that cooler water holds more oxygen than warmer.

Designing Watershed-based Education and Extension Efforts through a Mental Models Research ApproachUSDA-CSREES National Integrated Water Quality Program

Designing Watershed-based Education and Extension Efforts through a Mental Models Research ApproachUSDA-CSREES National Integrated Water Quality Program