Midterm Review #3

2. Factors involving living and once-living parts of an ecosystem.
3. Liquid water that flows across the land.
5. Organisms which can create their own food.
7. The first organisms to settle in any area are ________ species.
11. The flow of underground water, which occurs after infiltration.
12. A resource which is continually replaced.
15. Water that seeps into the ground.
16. All the organisms of one particular species in a given place
19. A consumer that eats animals.
21. Temperature is a(n) _________ factor in an ecosystem.
22. A relationship in which one organism benefits, and the other is neither harmed nor helped.
26. Competition type in which a species does not directly interact with its competitor.
27. Evaporation occurs because of heat from the ____.

1. An observation which shows how the individuals in a population are spaced.
4. A consumer which eats both plants and animals.
6. Population ___________ is the number of individuals per unit area.
8. In a food web, arrows always point ________ the organism doing the eating.
9. Two species or organisms trying to use the same resource are engaged in _______________.
10. Food energy is lost at each feeding level, mostly in the form of _______.
13. A consumer that eats plants.
14. Stage of water cycle in which water vapor becomes a liquid.
16. The ____________ cycle does not involve a stage where the chemical enters the atmosphere.
17. A relationship in which one species feeds upon another.
18. This type of growth occurs when a population has more available resources than it needs.
19. The largest number of organisms that an environment can suppport is called the _____________ capacity.
20. One organism lives in or on another, harming it but not normally killing it.
23. A relationship in which both organisms or species benefit.
24. In an ecological pyramid, autotrophs are always found at the ____ level.
25. The percentage of usable energy that transfers from one trophic level to the next.