24HRAS2

2. Cannot be penetrated by water.
4. Watershed for a major river draining into an ocean.
6. Organisms synthesizing organic compounds from inorganic substances via photosynthesis or chemosynthesis.
8. Water flow around soil particles or upward motion in plant tissues.
11. Naturally occurring inorganic material in Earth’s crust.
12. Resistance to flow, like friction in flowing water.
16. One-way transfer of energy in an ecosystem based on thermodynamics.
18. Single-celled microorganisms breaking down organic matter; some can cause diseases.
19. A molecule with one positive and one negative end.
21. Permeating a porous area with liquid or gas.
22. Precipitation discharge into streams when rainfall rate exceeds soil’s infiltration rate or water flowing off land surface without sinking into soil.
24. Heat needed for phase change, like melting or boiling.
26. Number of organisms per unit space or mass/volume compactness.

1. Water's sticky nature causing a "skin" at the air-water interface.
3. Group of cells functioning together in an organism.
5. Energy-yielding oxidation process in living plants and animals; gas exchange.
7. Wetland dominated by trees.
9. Oxygen present in water used by aquatic organisms for respiration.
10. Derived from living organisms or compounds containing carbon.
13. Scientific study of relations between living things and their environment.
14. To gather into a group or mass.
15. Heat energy needed to raise substance temperature.
17. Process in plant cells combining sunlight, carbon dioxide, and water to produce oxygen and carbohydrates.
20. Animals making seasonal movements; distances vary by species.
23. Water droplets condensed from air on cool surfaces, like grass or leaves.
25. Fine-grained soil with particles less than .002 mm; plastic when wet, hardens when dry.