photosynthesis

In this analysis and discussion activity, students learn why the biosphere requires a continuous inflow of energy, but does not need an inflow of carbon atoms. Students analyze how the process of photosynthesis illustrates the general principles of conservation of matter and the second Law of Thermodynamics.

Then, students analyze how carbon cycles and energy flow through ecosystems result from photosynthesis, biosynthesis, cellular respiration, and the trophic relationships in food webs. Thus, students learn how important ecological phenomena result from processes at the molecular, cellular and organismal levels.

This minds-on, hands-on activity begins with the driving question of how a tiny seed grows into a giant sequoia tree.

To address this question, students first consider what types of molecules and atoms are in plants. Next, they analyze data from an experiment on changes in plant biomass in the light vs. dark. Then, they conduct an experiment to evaluate changes in CO₂ concentration in the air around plants in the light vs. dark.

Students interpret these data to develop an increasingly accurate and evidence-based model of the contributions of photosynthesis and cellular respiration to changes in plant biomass.

This activity counteracts several common misconceptions about plant growth, photosynthesis, and cellular respiration. (NGSS)

To begin this hands-on, minds-on activity, students view a video about ecosystem changes that resulted when wolves were reintroduced to Yellowstone. Then, students learn about food chains and food webs, and they construct and analyze a food web for Yellowstone National Park. Students use what they have learned to understand trophic cascades caused by the return of wolves to Yellowstone.

Next, students learn that the biosphere requires a continuous inflow of energy, but does not need an inflow of carbon atoms. To understand why, students analyze how the carbon cycle and energy flow through ecosystems result from photosynthesis, biosynthesis, cellular respiration, and the trophic relationships in food webs.

In the final section, students use the concepts they have learned to understand trophic pyramids and phenomena such as the relative population sizes for wolves vs. elk in Yellowstone. Thus, students learn how important ecological phenomena result from processes at the molecular, cellular, and organismal levels.

For virtual instruction, you can use Food Webs – Understanding What Happened When Wolves Returned to Yellowstone, Carbon Cycles and Energy Flow through Ecosystems and the Biosphere, and Trophic Pyramids. 

In the first part of this activity, students learn how to use the floating leaf disk method to measure the rate of net photosynthesis (i.e. the rate of photosynthesis minus the rate of cellular respiration). They use this method to show that net photosynthesis occurs in leaf disks in a solution of sodium bicarbonate, but not in water. Questions guide students in reviewing the relevant biology and analyzing and interpreting their results. In the second part of this activity, student groups develop hypotheses about factors that influence the rate of net photosynthesis, and then each student group designs and carries out an investigation to test the effects of one of these factors. (NGSS)

In this analysis and discussion activity, students develop their understanding of photosynthesis by answering questions about three different models of photosynthesis.

These models are a chemical equation, a flowchart that shows changes in energy and matter, and a diagram that shows the basic processes in a chloroplast. Students use a drawing of a plant to create another model of photosynthesis.

Finally, students evaluate the advantages of each type of model for understanding photosynthesis; this helps them to appreciate the role of scientific models.

The Student Handout is available in the first two attached files and as a Google doc designed for use in distance learning and online instruction. (For additional information, see https://serendipstudio.org/exchange/bioactivities/Googledocs, especially item 7.) The Teacher Notes, available in the last two attached files, provide instructional suggestions and background information and explain how this activity is aligned with the Next Generation Science Standards.

The resources include:

These Teacher Notes summarize basic concepts and information related to energy, ATP, cellular respiration, and photosynthesis. These Teacher Notes also review common misconceptions and suggest a sequence of learning activities designed to develop student understanding of important concepts and overcome any misconceptions.

The attached files describe the key concepts, common misconceptions and suggested learning activities (in Word and PDF formats).

Students analyze evidence to evaluate four hypotheses about where a tree’s mass comes from. For example, students analyze Helmont’s classic experiment and evaluate whether his interpretation was supported by his evidence.

Thus, students engage in scientific practices as they learn that trees consist mainly of water and organic molecules and most of the mass of the organic molecules consists of carbon and oxygen atoms that came from carbon dioxide molecules in the air. (NGSS)

The Student Handout is available in the first two attached files and as a Google doc designed for use in distance learning and online instruction. (For additional instructions, see https://serendipstudio.org/exchange/bioactivities/Googledocs, especially item 7.) The Teacher Notes, available in the last two attached files, provide instructional suggestions and background information and explain how this activity is aligned with the Next Generation Science Standards.

In this minds-on activity, students analyze how photosynthesis, cellular respiration, and the hydrolysis of ATP provide energy for biological processes in plant cells.

Students learn that the glucose produced by photosynthesis are used for cellular respiration and for the synthesis of other organic molecules.

The final section challenges students to use their understanding of photosynthesis and cellular respiration to explain observed changes in biomass for plants growing in the light vs. dark.

The Teacher Notes suggest three possible additions to this learning activity. (NGSS)