| A | B |
|---|
| Temperature that water freezes | 0 degrees C |
| Temperature where water is densest | 4 degrees C |
| Coldest water in middle layer of frozen lake moves how | rises |
| warmer water in middle layer of frozen lake | sinks |
| When does the water in the ice at the top of the lake sink | In spring when it melts and warms to 4 degrees C |
| Spring turnover in a lake mixes this from top layer into rest of lake | oxygen |
| Spring turnover mixes this from bottom of lake into rest of lake | Nutrients |
| Turbidity | measure of how much light gets through water |
| relationship of dissolved oxygen and water temperature | inversely proportional |
| Layer of lake where dissolved oxygen is high throughout | top layer |
| Layer of lake where dissolved oxygen levels drop | middle layer |
| Layer of lake with low levels of dissovled oxygen | bottom layer |
| major decomposers in lakes and rivers | bacteria |
| plant eaters | herbivores or primary consumers |
| meat eaters | carnivores or secondary consumers |
| organisms that, like plants, make their own food | producers |
