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 field surveys, estimating a population, and reasoning from the population math aloud.
By the end of the Biodiversity & Populations unit, a student should be able to:
Six criteria, each judged Not yet / Approaching / Mastered (Page 3).
Run a biodiversity survey, then estimate a population by mark-recapture.
The student explains what the index and population math mean (Page 4).
Counts, index calculation, and population estimate 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 run the survey and justify the ecology 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 |
|---|---|---|
| Measuring diversity | ||
| Species richness | number of species | Just a count; ignores how common each species is |
| Species evenness | relative abundance | How evenly individuals are spread; one dominant species = low evenness |
| Simpson index | Simpson’s diversity | Weights evenness; a higher value means more diverse |
| Shannon index | Shannon–Wiener H | Folds richness and evenness into one number |
| Population dynamics | ||
| Exponential growth | J-curve | Unlimited growth; can’t hold for long in the real world |
| Logistic growth | S-curve | Levels off as it nears carrying capacity |
| Carrying capacity | K | The population size the environment can sustain |
| Mark-recapture | Lincoln index | Estimates a population you can’t count directly |
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| Species richness & evenness | Confuses how many species there are with how evenly they’re spread. | Counts species (richness) but ignores whether one dominates. | Distinguishes richness from evenness and explains why both shape a community’s biodiversity. |
| Diversity indices (Simpson & Shannon) | Cannot put a number on diversity at all. | Plugs data into an index but cannot interpret the result. | Calculates a Simpson or Shannon index from survey data and explains what a higher value means. |
| Population growth models | Assumes every population just keeps growing. | Names exponential and logistic growth but cannot tell which fits a dataset. | Distinguishes exponential from logistic growth and predicts which a population follows from its limiting factors. |
| Carrying capacity & life strategies | Has no sense of an environment’s population limit. | Defines carrying capacity but cannot link it to r- and K-strategists. | Uses carrying capacity (K), survivorship curves, and r- vs K-selection to predict a population’s trajectory. |
| Field technique (quadrat & mark-recapture) | Places the quadrat carelessly or botches the recapture count. | Runs the survey but records or tags samples inconsistently. | Runs a clean biodiversity survey and estimates population size by mark-recapture, defending the sampling design. |
| 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 interpretation over calculation: not just computing a Shannon index, but saying what a higher value means for the community. Ask “so what does that number tell you?”
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 | Species richness & evenness | NY / Appr / Mast | |
| 2 | Diversity indices (Simpson & Shannon) | NY / Appr / Mast | |
| 3 | Population growth models | NY / Appr / Mast | |
| 4 | Carrying capacity & life strategies | NY / Appr / Mast | |
| 5 | Field technique (quadrat & mark-recapture) | 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.