CHAPTER 3 VOCABULARY
1. ecology - scientific study of interactions among organisms and their environment.
2. biosphere - part of Earth in which life exists including land, water, and air or atmosphere.
3. species - group of similar organisms that can breed and produce fertile offspring.
4. population - group of individuals of the same species that live in the same area.
5. community - assemblage of different populations that live together in a defined area.
6. ecosystem - collection of all the organisms that live in a particular place, together with their nonliving environment.
7. biome - group of ecosystems that have the same climate and dominant communities.
8. autotroph - organism that can capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer.
9. photosynthesis - process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches.
10. chemosynthesis - process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates.
11. heterotroph - organism that obtains energy from the foods it consumes; also called a consumer.
12. herbivore - organism that obtains energy by eating only plants.
13. carnivore - organism that obtains energy by eating animals.
14. omnivore - organism that obtains energy by eating both plants and animals.
15. detritivore - organism that feeds on plant and animal remains and other dead matter.
16. decomposer - organism that breaks down and obtains energy from dead organic matter.
17. food chain - series of steps in an ecosystem in which organisms transfer energy by eating and being eaten.
18. food web - network of complex interactions formed by feeding relationships among the various organisms in an ecosystem.
19. trophic level - step in a food chain or food web.
20. ecological pyramid - diagram that shows the relative amounts of energy or matter within each trophic level in a food chain or food web.
21. biomass - total amount of living tissue within a given trophic level.
22. biogeochemical cycle - process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another.
23. evaporation - process by which water changes from a liquid into an atmospheric gas.
24. transpiration - loss of water from a plant through its leaves.
25. nutrient - chemical substance that an organism requires to live.
26. nitrogen fixation - process of converting nitrogen gas into ammonia.
27. denitrification - conversion of nitrates into nitrogen gas.
28. primary productivity - rate at which organic matter is created by producers in the ecosystem.
29. limiting factor - factor that causes the growth of a population to decrease.
30. algal bloom - an immediate increase in the amount of algae and other producers that results from a large input of a limiting nutrient.
CHAPTER 4 VOCABULARY
1. abiotic factor - Physical, or nonliving, factor that shapes an ecosystem.
2. aphotic zone - Permanently dark layer of the oceans below the photic zone.
3. benthos - Organisms that live attached to or close to the ocean floor.
4. biome - Group of ecosystems that have the same climate and dominant communities.
5. biotic factor - Biological influence on organisms within an ecosystem.
6. canopy - Dense covering formed by the leafy tops of tall rain forest trees.
7. climate - Average, year-after-year conditions of temperature and precipitation in a particular region.
8. coastal ocean - Marine zone that extends from the low-tide mark to the end of the continental shelf.
9. commensalism - Symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed.
10. competitive exclusion - Ecological rule that states that no two species can occupy the same niche in the same habitat at the same time.
11. coniferous - Term used to refer to trees that produce seed-bearing cones and have thin leaves shaped like needles.
12. coral reef - Diverse and productive environment named for the coral animals that make up its primary structure.
13. deciduous - Term used to refer to a tree that sheds its leaves during a particular season each year.
14. detritus - Particles of organic material that provide food for organisms at the base of an estuary's food web.
15. ecological succession - Gradual change in living communities that follows a disturbance.
16. estuary - Wetlands formed where rivers meet the oceans.
17. greenhouse effect - Natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases.
18. habitat - The area where an organism lives, including the biotic and abiotic factors that affect it.
19. humus - Material formed from decaying leaves and other organic matter.
20. kelp forest - Coastal ocean community named for its dominant organism - kelp, a giant brown alga.
21. mangrove swamp - Coastal wetland dominated by mangroves, salt-tolerant woody plants.
22. microclimate - Climate within a small area that differs significantly from the climate of the surrounding area.
23. mutualism - Symbiotic relationship in which both species benefit from the relationship.
24. niche - Full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions.
25. parasitism - Symbiotic relationship in which one organism lives in or on another organism (the host) and consequently harms it.
26. permafrost - Layer of permanently frozen subsoil in the tundra.
27. photic zone - Well-lit upper layer of the oceans.
28. phytoplankton - Population of algae and other small photosynthetic organisms found near the surface of the ocean and forming part of plankton.
29. pioneer species - First species to populate an area during primary succession.
30. plankton - Tiny, free-floating organisms that occur in aquatic environments.
31. polar zone - Cold climate zone where the sun's rays strike Earth at a very low angle.
32. predation - Interaction in which one organism captures and feeds on another organism.
33. resource - Any necessity of life, such as water, nutrients, light, food, or space.
34. salt marsh - Temperate-zone estuary dominated by salt-tolerant grasses above the low-tide line and seagrasses under water.
35. secondary succession - Succession following a disturbance that destroys a community without destroying the soil.
36. symbiosis - Relationship in which two species live closely together.
37. taiga - Biome in which the winters are cold but summers are mild enough to allow the ground to thaw.
38. temperate zone - Moderate climate zone between the polar zones and the tropics.
39. tolerence - Organism's capacity to grow or thrive when subjected to an unfavorable environmental factor.
40. tropical zone - Warm climate zone that receives direct or nearly direct sunlight year round.
41. understory - Layer in a rain forest formed by shorter trees and vines.
42. weather - Condition of Earth's atmosphere at a particular time and place.
43. wetland - Ecosystem in which water either covers the soil or is present at or near the surface of the soil for at least part of the year.
44. zonation - Prominant horizontal banding of organisms that live in a particular habitat.
45. zooplankton - Tiny animals that form part of the plankton.
46. primary succession - Succession that occurs on surfaces where no soil exists.