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 04 learning pathway.
The student demonstrates the following:
Five science criteria plus separately reported integration (Page 3).
Measure water uptake under changing conditions.
The student reasons from water potential and cohesion-tension aloud (Page 4).
Uptake readings, conditions, 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 take the measurement 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 |
|---|---|---|
| Water movement | ||
| Water potential | Ψ ; water free energy | Water flows from high to low potential — the driving force |
| Transpiration | leaf water loss | Evaporation from the leaves that pulls the water column |
| Cohesion-tension | cohesion-tension theory | Pull from the leaves + water sticking together = lift |
| Xylem | water-conducting tissue | Conducting vessels/tracheids are dead at maturity; other xylem cells can be living |
| Stomata & phloem | ||
| Guard cells | stomatal cells | Swell and shrink to open and close a stoma |
| Stoma (stomata) | leaf pore | Balances CO₂ intake against water loss |
| Phloem | sugar tissue | Moves sugar from source to sink by pressure-flow |
| Pressure-flow | mass flow | Sugar loaded at the source raises pressure that pushes sap to sinks |
| Nutrition | ||
| Mineral nutrient | essential element | Needed for function; root uptake and microbial partnerships can supply resources |
| Mycorrhiza | root-fungus association | Resource access can benefit the plant at a carbon cost; effects depend on conditions |
| Nitrogen fixation | N2 converted to reduced nitrogen | Certain microbes perform it; root absorption is not fixation |
| Nitrification | ammonium toward nitrite/nitrate | Different microbial transformations from N2 fixation |
| Source | sugar source | Where sugar is made and loaded into phloem (a leaf) |
| Sink | sugar sink | Where sugar is used or stored (a root, fruit, growing tip) |
| Root hair | absorptive cell extension | Increases root surface area; not a claim that foliar uptake never occurs |
| Criterion | Developing | Proficient | Mastery |
|---|---|---|---|
| Water potential | Cannot identify the direction of a potential gradient. | Uses one component without checking the total model. | Calculates and interprets total water potential in assigned cell/plant models, stating included and neglected components before predicting movement. |
| Transpiration & cohesion-tension | Believes the plant pushes water up from the roots. | Knows leaves lose water but not how that pulls the column upward. | Explains how transpiration at the leaves creates tension that pulls a cohesive water column up the xylem — roots absorb while leaves pull. |
| Stomatal control | Sees stomata as fixed holes that never change. | Knows guard cells open stomata but not what triggers it. | Explains how guard cells swell and shrink to open and close stomata, balancing CO₂ intake against water loss. |
| Phloem translocation & mineral nutrition | Confuses transport, mineral uptake, and nitrogen fixation. | Names partners but assumes every association benefits the plant. | Explains source-sink transport and mineral roles; distinguishes mycorrhizal uptake from microbial nitrogen fixation and evaluates context-dependent costs and benefits. |
| Lab technique (transpiration & the potometer) | Cannot safely prepare or read the approved setup. | Records uptake but ignores normalization or method limits. | Runs the approved investigation, normalizes uptake by time and leaf area, and explains uncertainty and why uptake only approximates transpiration. |
| 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.
The split between Proficient and Mastery is pulled, not pushed: not just noting leaves lose water, but explaining how that loss lifts the whole column. Ask “so what actually moves the water — the roots or the leaves?”
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | Water potential | Dev / Prof / Mast | |
| 2 | Transpiration & cohesion-tension | Dev / Prof / Mast | |
| 3 | Stomatal control | Dev / Prof / Mast | |
| 4 | Phloem translocation & mineral nutrition | Dev / Prof / Mast | |
| 5 | Lab technique (transpiration & the potometer) | 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.