This packet is everything a parent or guide needs to assess Unit 02 at home — learning targets, the answers that count as correct, the mastery rubric, calibration examples, and a clipboard score sheet. No multiple-choice test: the student shows mastery by running a plankton tow and reasoning from what they find under the microscope.
By the end of the Plankton & Primary Production unit, a student should be able to:
Six criteria, each judged Not yet / Approaching / Mastered (Page 3).
Sample, count, and identify phyto- and zooplankton — observed live.
The student explains the biology of primary production (Page 4).
Counts, identifications, and notes kept distinct.
You are making a decision, not adding up points. For each criterion, decide whether the work is Not yet, Approaching, or Mastered — the column language tells you which. A criterion counts as mastered only when the student can both work the microscope and justify the biology behind it. A student carries three tokens per term; one token buys a re-do of one criterion on another day, so a single bad afternoon never sinks the unit.
Accept any answer in the synonyms column — they are pre-approved as equivalent. The third column flags the confusions that look close but are not yet, so you can coach precisely.
| Canonical answer | Accepted synonyms | Common confusion / discriminator |
|---|---|---|
| Plankton | ||
| Phytoplankton | plant-like plankton; drifting algae | Photosynthesize in the sunlit zone — the ocean’s producers |
| Zooplankton | animal plankton | Graze on phytoplankton; includes copepods and larvae |
| Holoplankton | lifelong plankton | Planktonic for their whole life, unlike meroplankton |
| Meroplankton | larval plankton | Only planktonic as larvae (e.g. crab or fish larvae) |
| Production & the pump | ||
| Primary production | photosynthetic production | Sunlight fixed into food and oxygen in the euphotic zone |
| Euphotic zone | sunlit zone | Enough light for photosynthesis; production stops below it |
| Upwelling | nutrient upwelling | Deep, nutrient-rich water rising to the surface; fuels blooms |
| Biological pump | biological carbon pump | Sinking plankton carry carbon to the deep; phytoplankton make ~half of Earth’s oxygen |
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| Plankton types & classification | Uses “plankton” as one undifferentiated category. | Separates phytoplankton from zooplankton but confuses holoplankton with meroplankton. | Sorts plankton by role and by life history and explains what each does in the water column. |
| Primary production & photosynthesis | Thinks the open ocean’s food comes from plants on the seafloor. | Knows phytoplankton photosynthesize but cannot tie it to the sunlit zone. | Explains primary production in the euphotic zone — sunlight fixed into food and oxygen — and why it stops below the light. |
| Nutrients, upwelling & blooms | Assumes plankton grow evenly everywhere in the sea. | Names nutrients as a factor but not upwelling or seasonality. | Links nutrient limitation and upwelling to where and when blooms form, and predicts productive vs barren water. |
| Food-web base & the biological pump | Dismisses plankton as unimportant “scum.” | Knows plankton feed other animals but misses the carbon and oxygen story. | Places plankton at the food-web base, explains the biological carbon pump, and credits phytoplankton with about half of Earth’s oxygen. |
| Lab technique (plankton-tow microscopy) | Skips the tow or cannot find organisms under the scope. | Collects a sample but struggles to count or identify what is in it. | Runs a clean plankton tow — samples, counts, and identifies phyto- and zooplankton under the microscope. |
| Integration (cross-domain) | Treats the science as isolated facts; makes no cross-domain connection. | Names a link to history, reading, or writing but cannot defend why it matters. | Connects the unit to its anchor across History · Reading · Writing (plus chosen electives) and defends why the connection matters. |
The split between Approaching and Mastered is role in the system: not just naming a plankton, but explaining what it does — photosynthesize, graze, feed the web, pump carbon. Ask “so what does it do out here?”
Read these before you grade. They show what Mastered and Not yet actually sound like, plus the edge cases where you should coach rather than decide on the spot.
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | Plankton types & classification | NY / Appr / Mast | |
| 2 | Primary production & photosynthesis | NY / Appr / Mast | |
| 3 | Nutrients, upwelling & blooms | NY / Appr / Mast | |
| 4 | Food-web base & the biological pump | NY / Appr / Mast | |
| 5 | Lab technique (plankton-tow microscopy) | NY / Appr / Mast | |
| 6 | Integration (cross-domain) | NY / Appr / Mast |
☐ No ☐ Yes — for criterion: __________ Tokens remaining: ☐ 3 ☐ 2 ☐ 1 ☐ 0
NY = Not yet · Appr = Approaching · Mast = Mastered · Unsure between two levels? Circle the lower one and note what a re-do would need.