Plant Growth and Gas Exchange Unit

Contributor
Culturally relevant ecology, learning progressions and environmental literacy (NSF Grant #0832173): Jonathon Schramm, Eric Keeling, Dijanna Figueroa, Lindsay Mohan, Michele Johnson, and Charles W. Anderson
Type Category
Instructional Materials
Types
Unit
Note
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be "fully aligned," the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.

Reviews

Description

This model unit from Michigan State University includes 11 lessons that guide students through the process of collecting evidence and developing explanations of where the dry matter of plants comes from and of the roles of photosynthesis and respiration in the carbon cycle. Along with the focus on building explanations of these core ideas, the unit explicitly integrates the crosscutting concepts of matter and energy and scale, proportion, and quantity. This unit is built around the question of how small seeds grow into large plants, and the core activities of the unit guide students in tracing the mass changes that occur as seeds germinate and grow. These core activities are supported through a carefully planned sequence of learning and assessment activities that follow a research-based learning progression to support the development of student understanding.

Intended Audience

Educator and learner
Educational Level
  • High School
  • Middle School
Language
English
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

HS-LS1-6 Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.

Clarification Statement: Emphasis is on using evidence from models and simulations to support explanations.

Assessment Boundary: Assessment does not include the details of the specific chemical reactions or identification of macromolecules.

This resource appears to be designed to build towards this performance expectation, though the resource developer has not explicitly stated so.

Comments about Including the Performance Expectation
Overall, the unit focuses on how atmospheric carbon dioxide is fixed through photosynthesis to produce organic compounds that contribute to the biomass of a growing plant, and this focus aligns directly with the PE. Lessons 4 and 10 directly address the concept of biosynthesis of various compounds from the glucose formed during photosynthesis. However, teachers may wish to extend—particularly for advanced classes—the treatment of these concepts beyond what is provided in the unit. The final lesson ties the molecular, cellular, and organismal processes addressed in the previous lessons to the global carbon cycle, thus addressing HS-LS2-5 in an introductory manner. This might provide an excellent transition into a more thorough treatment of this Disciplinary Core Idea. Alternatively, teachers may consider modifying this unit to more directly address a bundle of performance expectations including HS-LS1-6 and HS-LS2-5. This unit directly addresses the practice of constructing and revising explanations, while also engaging students in conducting investigations, using models, and using mathematical and computational reasoning. The lesson also directly addresses the crosscutting concept of matter and energy, while also integrating a significant focus on scale.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
According to the unit authors, “The activities in this unit engage students in collecting data about plant growth and gas exchange, then in developing a scientific explanation for their observations.” Therefore, the unit is explicitly addressing the practice of constructing and revising explanations. Students begin the unit by constructing an explanation around the question of how plants grow. As students gain new experience and collect new evidence through investigations, demonstrations, readings, and discussions, they revise and deepen their explanations of photosynthesis, cellular respiration, and biosynthesis before ultimately connecting these processes to the global carbon cycle. Two embedded resources—a table entitled, “Unit Goals as Changes in Student Inquiry Practices and Accounts” and an ongoing discussion, “The Story of Adrienne,” of a typical student’s thinking—provide excellent guidance to teachers on how they can support student thinking and enactment of the relevant practices throughout the unit.

Disciplinary Core Ideas

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
Overall, the unit focuses on how atmospheric carbon dioxide is fixed through photosynthesis to produce organic compounds that contribute to the biomass of a growing plant, and this focus aligns directly with the Disciplinary Core Idea. Lessons 4 and 10 directly address the concept of biosynthesis of various compounds from the glucose formed during photosynthesis. However, teachers may wish to extend—particularly for advanced classes—the treatment of these concepts beyond what is provided in the unit. The final lesson ties the molecular, cellular, and organismal processes addressed in the previous lessons to the global carbon cycle, thus addressing LS-2B in an introductory manner. This might provide an excellent transition into a more thorough treatment of this Disciplinary Core Idea.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
The unit explicitly addresses the connection among processes at the atomic-molecular (photosynthesis and respiration), microscopic (gas exchange), macroscopic (organismal weight gain or loss), and landscape (carbon cycle) levels. The unit uses the Powers of 10 video and supporting materials to support student thinking about orders of magnitude. Building on that background, the unit includes a reading and simple chart that guides students to consider the atomic-molecular, microscopic, and macroscopic structures of plants, air, and soil. A visual resource that pulls these ideas together in the context of plants could help students make sense and support their explanations. One such resource from the Campbell Biology textbook is highlighted in this blog post (http://campbell-book.blogspot.com/2012/07/themes-connect-concepts-of-biology.html). Teachers could also support student understanding by engaging students in examining plants, particularly leaf structure, and soil samples microscopically.

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
The unit explicitly addresses energy and matter as environmental processes. The matter and energy process tools used throughout the unit make this crosscutting concept explicit to students by providing a framework in which students trace the flow of matter and energy through the processes of plant growth, photosynthesis, biosynthesis, and cellular respiration. These process tool graphic organizers could be easily converted to manipulatives to support student engagement through peer discussions or to support students who are struggling with unit concepts. The unit does focus more heavily on the conservation of matter within the processes presented than on the flow of energy.

Resource Quality

  • Alignment to the Dimensions of the NGSS: While the time requirements of this unit may present a practical challenge for teachers, the strong research foundation and excellent design of this unit make it a model resource. The unit begins with an engaging question that most students would think they are able to answer. However, the carefully designed sequence of learning experiences challenges common student misconceptions and guides students toward an accurate and evidence-based explanation of plant growth, photosynthesis, biosynthesis, and cellular respiration. Each learning experience, along with each of the embedded assessments, engages students in three-dimensional learning that integrates disciplinary core ideas, crosscutting concepts, and practices. Modifications to the unit might provide an excellent opportunity to address a bundle of performance expectations that focus around photosynthesis and respiration, energy flow in ecosystems, and carbon cycling. However, teachers should carefully weigh the effects of any modifications on the intentional design of the unit.

  • Instructional Supports: This unit has several features that effectively support student learning and that support teachers in implementing the lessons. The unit is designed around a research-based learning progression, and this progression is made explicit to teachers within the thoroughly documented teacher materials. The website for this resource also provides professional development materials that support the unit. The teacher guide includes extensive explanations of the goals and design of the unit, a unit goals table that explicates the learning progression, a concept map and summary table of unit activities that clarify how the sequence of unit lessons is designed to build toward targeted skills and understandings, and a detailed storyline (i.e. “The Story of Adrienne”) that tracks the thinking of a typical student throughout the unit. The regular, integrated formative assessment probes require students to formulate and commit their thinking to paper, allowing the student and teacher to evaluate and respond to learning as it occurs throughout the unit. The use of graphic organizers, such as the energy and matter process tools, helps students organize their thinking and provides a structure for student understanding. The teacher materials acknowledge that students will fall across a spectrum of understanding as they progress through the unit, and keys for open-response items provide sample student answers representing three levels of understanding. This will help teachers more precisely evaluate their own students. However, it is left to the teacher to determine the necessary instructional adjustments to help move students from one level to another. The graphic organizers used throughout the unit provide support to English language learners and will prove beneficial to the majority of students. The teacher may find it necessary, though, to further differentiate the lessons to meet the needs of struggling or gifted learners. For example, struggling students may benefit from the teacher creating manipulatives based on the matter and energy process tools, rather than having to generate the information needed to complete the graphic organizer on paper. Unit materials include the teacher guide, student handouts, student readings, and teacher presentations all of which are available on the resource website.

  • Monitoring Student Progress: The unit was intentionally designed to include regular formative assessments throughout. From the beginning of the unit, students are regularly asked to put their thinking down on paper. The process diagram graphic organizers provide a structure that organizes student responses and helps to shape their thinking. These regular formative assessments provide the teacher multiple opportunities to monitor student thinking and to adjust instruction to support student learning. The formative assessment storyline (i.e. “The Story of Adrienne”) supports teachers in understanding and guiding student thinking as they progress through the unit. The unit also includes summative assessments that can be used to evaluate student learning at the end of the unit. The assessments throughout the unit focus on students’ ability to draw on evidence to construct explanations that connect the core ideas of the unit to the crosscutting concepts of matter and energy and scale. Sample answers are provided for all assessments.

  • Quality of Technological Interactivity: This is not a technology-based resource. The unit does incorporate the use of laboratory sensor and data collection technology. In addition, the formative assessment items integrated throughout the unit could be administered through online technologies (e.g. Google Forms), which would facilitate the teacher’s ability to analyze and respond to class-level data generated through these assessments.