Life Science · California Grade 7

MS-LS1-6

Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.

Clarification statement: Emphasis is on tracing movement of matter and flow of energy.

Assessment boundary: Assessment does not include the biochemical mechanisms of photosynthesis.

Source: California Department of Education, NGSS Preferred Integrated Course Model, Grade 7 (accessed 2026-10-18)

Chapters

Chapter 4: Capturing the Sun's Energyassesses

The whole lesson is this PE: students use experimental evidence (the willow, leaf disks in Lab 1, Ingenhousz and de Saussure) to explain that a producer's matter comes from carbon dioxide and water and its energy from light. Lab 1, W6 and the exit ticket produce written explanations that trace matter and energy into and out of the producer, within the assessment boundary (no biochemical mechanism is taught or assessed).

Chapter 5: Using Stored Energysupports

Lesson 4 assessed this PE. Here photosynthesis is the background that explains where sugar and oxygen come from; the comparison slides and W9 use it to trace matter and energy into and out of organisms, but no task constructs the photosynthesis explanation itself.

Chapter 7: Global Cycles of Mattersupports

Photosynthesis is treated here only as the process that moves carbon and water into producers, which is background from Lesson 4; students are not asked to construct the full explanation of photosynthesis in this chapter.

Worksheets (18)

Chapter	Worksheet	Role	How it connects
Ch. 4	W1 · The Plant on the Wire: Gaining Mass with No Soil Phenomenon exploration	supports	Students meet the puzzle the PE answers: a producer gains matter without soil. They record observations and a first explanation; the full evidence-based explanation of photosynthesis comes in later worksheets.
Ch. 4	W2 · Matter Words, Energy Words: The Language of Producers Vocabulary in action	supports	The PE asks students to trace matter and energy through photosynthesis. Keeping 'matter words' and 'energy words' apart, and knowing which terms name inputs, outputs and structures, is the vocabulary that makes that tracing possible.
Ch. 4	W3 · The Willow, the Mint and the Jars: Finding Out What Plants Are Made Of Reading with evidence	practice	Students trace the evidence that matter enters a plant from carbon dioxide and water, with light as the energy source. They practice building an explanation from historical evidence, the same move the PE asks for, without the biochemical mechanism.
Ch. 4	W4 · Reading the Leaf: Inputs, Outputs and a Balanced Equation Diagrams and models	practice	Tracing the movement of matter and the flow of energy through a leaf, and counting atoms across the equation, is the core reasoning of this PE. The equation is used only to track atoms and energy, not to describe the biochemical mechanism, which the assessment boundary excludes.
Ch. 4	W5 · Bubbles and Sensors: Two Datasets on Light and Photosynthesis Data and graphing	practice	Students analyze evidence that light drives a plant's uptake of carbon dioxide and release of oxygen, the data they will cite in an explanation of photosynthesis's role in moving matter and energy. No biochemical mechanism is involved.
Ch. 4	W6 · The Sealed Greenhouse Ledger: Where Did the Basil's Mass Come From? Claim, evidence, reasoning	assesses	The CER asks for a scientific explanation, based on evidence, of how matter moves into a plant through photosynthesis and where the energy comes from. It traces matter and energy only; no biochemical mechanism is required, which respects the assessment boundary.
Ch. 4	W7 · Fixing Dario's Notebook: Eight Claims About Producers Error analysis	practice	Each notebook entry contains a flawed explanation of how matter or energy moves through a producer. Diagnosing and correcting them sharpens the explanation students will construct for the PE, without entering the biochemical mechanism.
Ch. 4	W8 · Follow the Evidence: A Photosynthesis Jigsaw Collaborative investigation	practice	Students assemble an evidence-based explanation of where a producer's matter comes from, what light is needed for, what photosynthesis produces and what happens to the sugar. This is the explanation the PE asks for, built collaboratively from evidence cards, without the biochemical mechanism.
Ch. 4	W9 · Fuel for the Island Ferry: Choosing a Biomass Source Transfer and design	supports	Every candidate fuel is biomass whose stored chemical energy was captured from sunlight by producers; the justification asks students to trace that matter and energy, which is background for the PE rather than a full explanation of photosynthesis.
Ch. 4	W10 · Capturing the Sun's Energy: Mastery Check Retrieval and mastery check	assesses	The mixed items check the ideas the explanation depends on, and the synthesis paragraph asks for an evidence-based explanation of photosynthesis's role in moving matter and energy into a producer. No item asks for the biochemical mechanism.
Ch. 5	W1 · Warm Seeds in a Dark Flask: Where Did the Energy Come From? Phenomenon exploration	supports	The flask is kept dark on purpose, so students must rule out photosynthesis from the last lesson and look for a different process that works without light.
Ch. 5	W2 · Reactant or Product? Fuel or Building Block? Working the Words Vocabulary in action	supports	Part D asks students to compare the roles of oxygen and carbon dioxide in photosynthesis and in cellular respiration, which connects this lesson's words to the previous one.
Ch. 5	W5 · Oxygen Used by Sprouting Seeds, and Energy per Gram of Food: Two Datasets Data and graphing	supports	The seeds are kept in the dark so that photosynthesis cannot be the cause of any gas change, which makes the comparison with the previous lesson explicit.
Ch. 5	W6 · Do Plants Run on Oxygen Too? A Claim-Evidence-Reasoning Case Claim, evidence, reasoning	supports	The lamp-on data show photosynthesis removing carbon dioxide while respiration continues, so students must keep both processes in mind at once; this connects the two lessons' explanations of matter and energy.
Ch. 5	W10 · Using Stored Energy: Mastery Check Retrieval and mastery check	supports	Items 9 and 13 connect photosynthesis to cellular respiration by the roles of oxygen and carbon dioxide and by tracing a carbon atom through both processes.
Ch. 7	W4 · Reading the Carbon Loop, Drawing the Nitrogen Loop Diagrams and models	supports	Reading the photosynthesis arrow in the carbon loop reinforces that producers bring carbon from the nonliving world into living things. The task does not ask for the explanation of photosynthesis's role that the PE itself requires.
Ch. 7	W5 · Carbon by the Hour, Nitrogen by the Week: Two Teaching Datasets Data and graphing	supports	The day-night pattern in carbon dioxide is the signature of photosynthesis in light and cellular respiration at all hours. The sheet uses the pattern as evidence but does not ask for the explanation the PE requires.
Ch. 7	W7 · Fixing Marco's Cycle Poster: Seven Claims That Break the Rules Error analysis	supports	Two claims concern where a plant's mass comes from. Correcting them relies on the role of photosynthesis in bringing carbon from the air into organisms, which is the heart of this PE, though the sheet does not ask for a full explanation.

Labs (6)

Chapter	Lab	Role	How it connects
Ch. 4	Lab 1 · The Rising Disks: What Makes a Sunken Leaf Float? Evidence-based mystery	assesses	Students collect their own light-versus-dark and carbon-dioxide-versus-none data and write an explanation that traces a matter input (carbon dioxide) and an energy input (light) into the leaf and a matter output (oxygen) out of it, which is evidence toward the PE as written and stays inside its boundary (no biochemical mechanism).
Ch. 4	Lab 2 · Follow the Atoms, Follow the Energy: A Sealed-Jar Model Collaborative systems modeling	assesses	Students use their token record to write an explanation of how carbon dioxide and water become a producer's body and how light energy becomes stored chemical energy and then heat. The explanation traces matter and energy without any biochemical mechanism, which matches the PE and its assessment boundary.
Ch. 4	Lab 3 · Fuel for Flight: Which Biomass Should Become Jet Fuel? Data-driven decision	supports	Questions 6 and 7 make students trace the energy in every candidate fuel back to sunlight captured by photosynthesis and the carbon back to carbon dioxide, and explain why burning a biofuel still releases carbon dioxide. This is the lesson's science applied, not new evidence toward the PE.
Ch. 5	Lab 3 · Field Investigation: What Your Body Changes When Your Muscles Work Harder Classroom field investigation	supports	The investigation shows energy from food leaving the body as work and heat and carbon dioxide leaving in breath, the organism-level end of the energy flow that photosynthesis began.
Ch. 7	Lab 1 · Passport of a Carbon Atom: Where Do the Atoms Pile Up? Collaborative systems modeling	supports	The producers station's incoming arrow is photosynthesis; students use it as a process name without being asked to explain its mechanism.
Ch. 7	Lab 2 · Two Jars, One Lid: Does a Closed System Keep Its Mass? Physical model	supports	Students reason that a seedling's new mass came from the jar's air and water rather than from nothing, which uses the role of photosynthesis as background without requiring the full explanation.