Science Task Screener

Task Title: Photosynthesis: Capturing Light as Chemical Energy

Grade: High School

Date: 2024-05-20

Instructions

Criterion A. Tasks are driven by high-quality scenarios that are grounded in phenomena or problems.

i. Making sense of a phenomenon or addressing a problem is necessary to accomplish the task.

What was in the task, where was it, and why is this evidence?

  1. Is a phenomenon and/or problem present?

Students must use the Photosynthesis simulation to make sense of the puzzling phenomenon of how a tiny seed grows into a massive tree — specifically, where the tree’s mass comes from. The task challenges the common misconception that tree mass comes from soil, instead revealing through the simulation and chemical equation that most biomass comes from CO₂ in the air.

  1. Is information from the scenario necessary to respond successfully to the task?

Yes, students must extract specific oxygen bubble count data from the simulation’s bubble counter and data table across multiple experimental conditions (varying light intensity, temperature, CO₂ concentration, and light wavelength) to perform the analysis and reasoning needed to construct their model and CER explanation. The anchoring phenomenon is referenced throughout Parts 3 and 4, requiring students to connect their simulation data back to the question of tree mass origin.

ii. The task scenario is engaging, relevant, and accessible to a wide range of students.

Features of engaging, relevant, and accessible tasks:

Features of scenarios Yes Somewhat No Rationale
Scenario presents real-world observations [x] [ ] [ ] Grounded in the observable phenomenon of a tiny acorn growing into a massive oak tree — a common experience for students
Scenarios are based around at least one specific instance, not a topic or generally observed occurrence [x] [ ] [ ] Specific instance of an acorn growing into an oak tree, posing a concrete puzzle about where the mass comes from
Scenarios are presented as puzzling/intriguing [x] [ ] [ ] The question “where does the mass come from?” is genuinely surprising — most people incorrectly assume soil is the primary source
Scenarios create a “need to know” [x] [ ] [ ] Students need to understand photosynthesis at the molecular level to explain how atmospheric CO₂ becomes plant biomass
Scenarios are explainable using grade-appropriate SEPs, CCCs, DCIs [x] [ ] [ ] Aligns tightly with HS-LS1-5 and Developing and Using Models
Scenarios effectively use at least 2 modalities (e.g., images, diagrams, video, simulations, textual descriptions) [x] [ ] [ ] Text description of the tree mass phenomenon, interactive simulation with sliders and bubble counter, real-time data table, and graph display
If data are used, scenarios present real/well-crafted data [x] [ ] [ ] Simulation generates realistic oxygen production data that is consistent with known photosynthesis response curves
The local, global, or universal relevance of the scenario is made clear to students [x] [ ] [ ] Photosynthesis is the foundation of almost all life on Earth, producing the oxygen we breathe and the food we eat; understanding it connects to climate change, agriculture, and global carbon cycles
Scenarios are comprehensible to a wide range of students at grade-level [x] [ ] [ ] The acorn-to-oak tree phenomenon is universally accessible; no specialized background knowledge required to find the question interesting
Scenarios use as many words as needed, no more [x] [ ] [ ] The phenomenon is described concisely in a few paragraphs that directly create the intellectual need
Scenarios are sufficiently rich to drive the task [x] [ ] [ ] The phenomenon naturally leads into data collection, analysis, model development, and CER argumentation spanning all four investigations
Evidence of quality for Criterion A: [ ] No [ ] Inadequate [ ] Adequate [x] Extensive

Suggestions for improvement of the task for Criterion A:

Consider including a historical note about Jan Baptista van Helmont’s willow tree experiment (1648), in which he grew a willow tree in a pot of soil for 5 years and found that the soil lost negligible mass while the tree gained ~74 kg — a powerful historical puzzle that deepens the phenomenon.

Criterion B. Tasks require sense-making using the three dimensions.

i. Completing the task requires students to use reasoning to sense-make about phenomena or problems.

Consider in what ways the task requires students to use reasoning to engage in sense-making and/or problem solving.

Students must reason from their experimental oxygen bubble data to infer how environmental factors (light intensity, temperature, CO₂, wavelength) affect the rate of photosynthesis, then integrate those findings into a systems-level model that traces matter and energy flows from sunlight → chloroplast → sugar → plant biomass. This goes beyond simple recall of the photosynthesis equation — students must construct and justify a mechanistic model linking multiple variables to the molecular process.

ii. The task requires students to demonstrate grade-appropriate dimensions:

Evidence of SEPs (which element[s], and how does the task require students to demonstrate this element in use?)

Students develop and use a model to illustrate how photosynthesis transforms light energy into stored chemical energy. They construct a visual model (concept map, flow chart, annotated diagram, or system model) that includes components (light energy, CO₂, H₂O, sugar, O₂, chloroplasts, chlorophyll), relationships (how environmental factors affect photosynthetic rate), and connections (matter and energy flow between organism and environment). The model is informed by their own simulation data (Developing and Using Models).

Evidence of CCCs (which element[s], and how does the task require students to demonstrate this element in use?)

Students track changes of energy and matter in the photosynthetic system, describing matter and energy flows into, out of, and within the system. They trace light energy from sunlight through the photosynthetic process into the chemical bonds of sugar molecules, and account for how carbon atoms from atmospheric CO₂ become the organic matter of the tree. They recognize that energy stored in sugar represents the difference between bond energies of inputs versus outputs (Energy and Matter).

Evidence of DCIs (which element[s], and how does the task require students to demonstrate this element in use?)

Students apply their understanding that the process of photosynthesis converts light energy to stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen. They recognize that the sugar molecules thus formed contain carbon, hydrogen, and oxygen, and that the hydrocarbon backbones are used to build the plant’s structural biomass (DCI: LS1.C Organization for Matter and Energy Flow in Organisms).

iii. The task requires students to integrate multiple dimensions in service of sense-making and/or problem-solving.

Consider in what ways the task requires students to use multiple dimensions together.

The prompt in Part 4 explicitly asks students to construct a visual model that includes components (DCI), relationships from simulation data (SEP), and connections tracing matter and energy flows (CCC). The CER component then forces synthesis: students must cite quantitative simulation data (SEP) as evidence that photosynthesis converts light energy to chemical energy (DCI), while reasoning about matter transfer and energy flow through the system (CCC).

iv. The task requires students to make their thinking visible.

Consider in what ways the task explicitly prompts students to make their thinking visible (surfaces current understanding, abilities, gaps, problematic ideas).

Students make their thinking visible by: (1) recording raw oxygen bubble counts in structured data tables across four investigations, (2) writing analysis responses about patterns in each environmental variable, (3) constructing a visual model showing system components, relationships, and connections, and (4) writing a comprehensive CER argument with explicit claim, evidence, and reasoning sections connecting simulation data to the tree mass phenomenon.

Evidence of quality for Criterion B: [ ] No [ ] Inadequate [ ] Adequate [x] Extensive

Suggestions for improvement of the task for Criterion B:

Consider asking students to explicitly label energy storage directions (energy in → energy stored) and bond energy differences on their visual model to deepen the connection between light energy and chemical bond energy.

Criterion C. Tasks are fair and equitable.

i. The task provides ways for students to make connections of local, global, or universal relevance.

Consider specific features of the task that enable students to make local, global, or universal connections to the phenomenon/problem and task at hand. Note: This criterion emphasizes ways for students to find meaning in the task; this does not mean “interest.” Consider whether the task is a meaningful, valuable endeavor that has real-world relevance–that some stakeholder group locally, globally, or universally would be invested in.

Photosynthesis is the foundation of the global carbon cycle, the primary source of atmospheric oxygen, and the basis of the food web that sustains all life on Earth. Understanding it connects to climate change (CO₂ fertilization, carbon sequestration), agriculture (optimizing growing conditions), renewable energy (artificial photosynthesis, biofuels), and global food security.

ii. The task includes multiple modes for students to respond to the task.

Describe what modes (written, oral, video, simulation, direct observation, peer discussion, etc.) are expected/possible.

Students respond via structured data tables (written), manipulation of an interactive simulation (kinesthetic/visual), written analysis questions, construction of a visual model (diagrammatic), and a comprehensive CER argument (written). The CSV export feature also allows students to work with their data in spreadsheet software for additional analysis.

iii. The task is accessible, appropriate, and cognitively demanding for all learners (including English learners or students working below/above grade level).

Features Yes Somewhat No Rationale
Task includes appropriate scaffolds [x] [ ] [ ] The task builds from observation and questioning to structured data collection through four scaffolded investigations, then to analysis, visual model construction, and CER argumentation
Tasks are coherent from a student perspective [x] [ ] [ ] The 5E structure provides a natural narrative flow from the puzzling phenomenon through investigation to explanation and model development
Tasks respect and advantage students’ cultural and linguistic backgrounds [x] [ ] [ ] The phenomenon of plant growth is universal — every student has seen a plant grow — and the context is accessible across cultures
Tasks provide both low- and high-achieving students with an opportunity to show what they know [x] [ ] [ ] Structured data collection provides an entry point for all students, while the CER and visual modeling phases allow students to demonstrate deeper understanding
Tasks use accessible language [x] [ ] [ ] Technical vocabulary (photosynthesis, chloroplast, chlorophyll, wavelength) is introduced in context with clear connections to the phenomenon

iv. The task cultivates students’ interest in and confidence with science and engineering.

Consider how the task cultivates students interest in and confidence with science and engineering, including opportunities for students to reflect their own ideas as a meaningful part of the task; make decisions about how to approach a task; engage in peer/self-reflection; and engage with tasks that matter to students.

By empowering students to act as plant biologists investigating how environmental factors affect photosynthetic rate through an interactive simulation, the task fosters engagement and confidence in experimental design, data analysis, and scientific modeling. The surprising answer to the tree mass question (it comes mostly from CO₂, not soil) generates genuine curiosity and challenges prior misconceptions.

v. The task focuses on performances for which students’ learning experiences have prepared them (opportunity to learn considerations).

Consider the ways in which provided information about students’ prior learning (e.g., instructional materials, storylines, assumed instructional experiences) enables or prevents students’ engagement with the task and educator interpretation of student responses.

The task assumes basic knowledge of the photosynthesis equation and the general concept that plants use sunlight, but scaffolds the specific model development and CER format directly within the activity. The four scaffolded investigations ensure students can build understanding progressively.

vi. The task presents information that is scientifically accurate.

Describe evidence of scientific inaccuracies explicitly or implicitly promoted by the task.

All photosynthetic rate responses to light intensity, temperature, CO₂ concentration, and light wavelength accurately reflect established plant physiology principles, including light saturation, temperature optima, CO₂ limitation, and the chlorophyll absorption spectrum.

Evidence of quality for Criterion C: [ ] No [ ] Inadequate [ ] Adequate [x] Extensive

Suggestions for improvement of the task for Criterion C:

Provide sentence starters for the CER argument and a pre-made template for the visual model for students who need additional scaffolding with scientific writing and diagramming.

Criterion D. Tasks support their intended targets and purpose.

Before you begin:

  1. Describe what is being assessed. Include any targets provided, such as dimensions, elements, or PEs:

The task assesses students’ ability to develop and use a model to illustrate how photosynthesis transforms light energy into stored chemical energy, tracing matter and energy flows through the photosynthetic system, aligned to HS-LS1-5.

  1. What is the purpose of the assessment? (check all that apply)
    • [x] Formative (including peer and self-reflection)
    • [ ] Summative
    • [x] Determining whether students learned what they just experienced
    • [ ] Determining whether students can apply what they have learned to a similar but new context
    • [ ] Determining whether students can generalize their learning to a different context
    • [ ] Other (please specify): N/A

i. The task assesses what it is intended to assess and supports the purpose for which it is intended.

Consider the following:

  1. Is the assessment target necessary to successfully complete the task?

Yes, understanding that photosynthesis converts light energy into chemical bond energy stored in sugar molecules, and that the carbon atoms in plant biomass come from atmospheric CO₂, is essential to correctly constructing the visual model and CER argument.

  1. Are any ideas, practices, or experiences not targeted by the assessment necessary to respond to the task? Consider the impact this has on students’ ability to complete the task and interpretation of student responses.

Basic skills in data recording and graph interpretation are required, which might act as a barrier if not scaffolded. The CSV export feature requires basic spreadsheet knowledge.

  1. Do the student responses elicited support the purpose of the task (e.g., if a task is intended to help teachers determine if students understand the distinction between cause and correlation, does the task support this inference)?

The visual model with explicit component, relationship, and connection elements, combined with the CER argument, directly supports assessing whether students understand photosynthesis as a system of matter and energy transformation — not just a memorized chemical equation.

ii. The task elicits artifacts from students as direct, observable evidence of how well students can use the targeted dimensions together to make sense of phenomena and design solutions to problems.

Consider what student artifacts are produced and how these provide students the opportunity to make visible their 1) sense-making processes, 2) thinking across all three dimensions, and 3) ability to use multiple dimensions together [note: these artifacts should connect back to the evidence described for Criterion B].

The visual model and accompanying CER argument together provide artifacts that explicitly tie quantitative simulation data (SEP: Developing and Using Models) to matter and energy flow through the system (CCC: Energy and Matter) and the core mechanism of photosynthesis as an energy-conversion process (DCI: LS1.C).

iii. Supporting materials include clear answer keys, rubrics, and/or scoring guidelines that are connected to the three-dimensional target. They provide the necessary and sufficient guidance for interpreting student responses relative to the purpose of the assessment, all targeted dimensions, and the three-dimensional target.

Consider how well the materials support teachers and students in making sense of student responses and planning for follow up (grading, instructional moves), consistent with the purpose of and targets for the assessment. Consider in what ways rubrics include:

  1. Guidance for interpreting student thinking using an integrated approach, considering all three dimensions together as well as calling out specific supports for individual dimensions, if appropriate:

The teacher notes clearly break down how student responses map to the SEPs, DCIs, CCCs, and the exact NGSS evidence statements for HS-LS1-5.

  1. Support for interpreting a range of student responses, including those that might reflect partial scientific understanding or mask/misrepresent students’ actual science understanding (e.g., because of language barriers, lack of prompting or disconnect between the intent and student interpretation of the task, variety in communication approaches):

Multiple response modalities (data tables, analysis questions, visual model, CER argument) allow teachers to pinpoint exactly where a student’s understanding might be breaking down — whether at the data collection, pattern identification, or model construction level.

  1. Ways to connect student responses to prior experiences and future planned instruction by teachers and participation by students:

The elaboration section prompts students to connect their model to the broader carbon cycle and cellular respiration, preparing them for future instruction on energy flow through ecosystems (HS-LS2-3, HS-LS2-4) and cellular respiration (HS-LS1-7).

iv. The task’s prompts and directions provide sufficient guidance for the teacher to administer it effectively and for the students to complete it successfully while maintaining high levels of students’ analytical thinking as appropriate.

Consider any confusing prompts or directions, and evidence for too much or too little scaffolding/supports for students (relative to the target of the assessment—e.g., a task is intended to elicit student understanding of a DCI, but their response is so heavily scripted that it prevents students from actually showing their ability to apply the DCI).

The 5E layout and precise step-by-step instructions for each of the four simulation investigations guide students without providing the answers, ensuring high cognitive demand is maintained particularly in the visual model construction and CER argumentation phases of Part 4.

Evidence of quality for Criterion D: [ ] No [ ] Inadequate [ ] Adequate [x] Extensive

Suggestions for improvement of the task for Criterion D:

Provide teachers with sample completed data tables and a model CER argument and visual model for scoring reference. Consider adding a peer-review component where students evaluate each other’s models using the component/relationship/connection framework.

Overall Summary

Consider the task purpose and the evidence you gathered for each criterion. Carefully consider the purpose and intended use of the task, your evidence, reasoning, and ratings to make a summary recommendation about using this task. While general guidance is provided below, it is important to remember that the intended use of the task plays a big role in determining whether the task is worth students’ and teachers’ time.

The “Photosynthesis: Capturing Light as Chemical Energy” task is highly aligned with the NGSS. It effectively engages students with an anchoring phenomenon (a tiny seed growing into a massive tree — where does the mass come from?) and guides them through an authentic investigation using the Photosynthesis simulation. Students must develop a model (SEP: Developing and Using Models) that traces the flow of matter and energy (CCC: Energy and Matter) through the photosynthetic system (DCI: LS1.C) to construct evidence-based explanations of how plants convert light energy into stored chemical energy. The task scores extensive across all criteria due to its robust integration of three-dimensional learning and sensemaking.

Final recommendation (choose one):