Use these targets, vocabulary, rubrics, examples, and score sheet with the instructor's approved lesson and procedure. This is an assessment companion, not a complete lesson or safety authorization.
Student lessons, data, and worked answers: Unit 03 learning pathway.
The student demonstrates the following:
Five science criteria plus separately reported integration (Page 3).
Measure photosynthetic rate and separate leaf pigments.
The student traces energy and carbon through the system aloud (Page 4).
Disk-rise times, chromatograms, and conclusions kept distinct.
You are making a decision, not adding up points. For each criterion, decide whether the work is Developing, Proficient, or Mastery — the column language tells you which. A criterion counts as mastered only when the student can both run the lab and justify the plant biology behind it. Each student has three tokens per term; each token retries one rubric criterion. Approved accommodations, equipment failures, and approved absences are handled separately and do not consume these tokens.
Accept listed synonyms; use the distinction column to resolve near-matches.
| Canonical answer | Accepted synonyms | Common confusion / discriminator |
|---|---|---|
| Two stages | ||
| Light reactions | light-dependent stage | On the thylakoid membranes; make ATP and NADPH |
| Calvin cycle | light-independent stage; carbon fixation | In the stroma; fixes CO₂ into sugar — not “night-only” |
| ATP & NADPH | energy carriers | Made by the light reactions; spent in the Calvin cycle |
| Carbon fixation | CO₂ fixing | Building sugar from CO₂ — the source of plant mass |
| Chloroplast & pigments | ||
| Chloroplast | photosynthesis organelle | Where both stages happen; not in every cell |
| Thylakoid | membrane stack; grana | Site of the light reactions |
| Stroma | chloroplast fluid | Site of the Calvin cycle |
| Chlorophyll | green pigment | Absorbs red and blue, reflects green — why leaves look green |
| Pathways & mass | ||
| C3 / C4 / CAM | carbon-fixation pathways | Different strategies for the carbon-vs-water trade-off |
| Cellular respiration | sugar breakdown | Releases the energy stored in sugar; plants do it too |
| Dry mass | biomass | Comes mostly from atmospheric CO₂, not the soil |
| Stomata | leaf pores | Let CO₂ in for the Calvin cycle; also lose water |
The split between Proficient and Mastery is following the energy and carbon: not just naming a stage, but saying what it makes and where the plant's substance comes from. Ask “so where does the plant's mass actually come from?”
| Criterion | Developing | Proficient | Mastery |
|---|---|---|---|
| Light reactions & the Calvin cycle | Treats photosynthesis as one vague step that “makes food.” | Names the two stages but cannot say what each produces or consumes. | Traces light energy to ATP and NADPH in the light reactions and their use to fix CO₂ into sugar in the Calvin cycle. |
| Chloroplast structure & pigments | Cannot locate where photosynthesis happens in the cell. | Names the chloroplast but not the thylakoids, stroma, or why leaves are green. | Maps the light reactions to the thylakoids and the Calvin cycle to the stroma, and explains how chlorophyll and accessory pigments absorb different wavelengths. |
| C3, C4 & CAM pathways | Assumes every plant fixes carbon the same way. | Names the pathways but cannot link them to climate or leaf structure. | Compares C3, C4, and CAM, and explains how each manages the trade-off between fixing carbon and losing water. |
| Respiration & the source of plant mass | Confuses mineral uptake with organic carbon fixation. | Names photosynthesis but omits respiration or seed reserves. | Traces carbon from CO2 and seed reserves where relevant; distinguishes respiration in light/dark and net versus gross exchange under stated assumptions. |
| Lab technique (floating-disk assay & pigment chromatography) | Cannot run the approved assay or pigment separation. | Records results but ignores controls or what the method measures. | Runs approved disk and pigment work, records controlled measurements, and explains proxy-rate and sampling limits rather than claiming a direct gross rate. |
| Integration (cross-domain) | Makes no supported connection between the source and the science. | Uses the source but needs help connecting evidence, writing, or limitations to the science. | Independently connects History, Reading, and Writing using a cited source, appropriate evidence, a limitation, and a scientific explanation. |
Read these before you grade. They show what Mastery and Developing actually sound like, plus the edge cases where you should coach rather than decide on the spot.
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | Light reactions & the Calvin cycle | Dev / Prof / Mast | |
| 2 | Chloroplast structure & pigments | Dev / Prof / Mast | |
| 3 | C3, C4 & CAM pathways | Dev / Prof / Mast | |
| 4 | Respiration & the source of plant mass | Dev / Prof / Mast | |
| 5 | Lab technique (floating-disk assay & pigment chromatography) | Dev / Prof / Mast | |
| 6 | Integration (cross-domain) | Dev / Prof / Mast |
☐ No ☐ Yes — for criterion: __________
Tokens left this term after this session (choose one): ☐ 3 ☐ 2 ☐ 1 ☐ None left
Dev = Developing · Prof = Proficient · Mast = Mastery · Unsure between two levels? Circle the lower one and note what a re-do would need.