Biology - Crossword Assignment

2. A process that releases energy from organic molecules, especially carbohydrates in the absence of oxygen
3. A category of organisms that is defined by how the organisms gain their energy
6. All the water found on Earth, including lakes, oceans and ground lakes
7. Ecosystem An ecosystem that is land-based
9. An ecosystem that is capable of withstanding pressure and giving support to a variety of organisms
12. Regions of Earth where living organisms exist
13. A process in which nutrient levels in aquatic ecosystems increase, leading to an increase in the populations of primary producers
15. Total mass of living organisms in a defined group or area
18. Warming of the Earth as a result of greenhouse gases, which trap some of the energy that would otherwise leave Earth.
20. Atmospheric gases that prevent heat from leaving the atmosphere, thus increasing the temperature of the atmosphere
21. A process in which materials, especially toxins, are ingested by an organism at a rate greater than they are eliminated

1. The living parts of an ecosystem
4. A process that changes solar energy into chemical energy
5. Hard (or soily) part of the Earth's surface
8. Efficiency A measure of the amount of energy or biomass transferred from one trophic levels to the next higher trophic level
10. Ecosystem An ecosystem that is water-based, either fresh water or salt water
11. The layer of gases above the Earth's atmosphere
13. All the interacting parts of a biological community/environment
14. Rain, snow or fog that is unnaturally acidic due to gases in the atmosphere that react with water to form acids.
16. The non-living parts of an ecosystem
17. A chemical that is essential to living things and is cycled through ecosystems
19. Respiration A process that releases energy from organic molecules, especially carbohydrates in the presence of oxygen