Ch.5 Key Terms

Question 1

photosynthesis

Answer 1

the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.

Question 2

producer

Answer 2

an organism, either a green plant or bacterium, which is part of the first level of a food chain.

Question 3

consumer

Answer 3

organisms that need to eat (i.e. consume) food to obtain their energy.

Question 4

decomposer

Answer 4

an organism, especially a soil bacterium, fungus, or invertebrate, that decomposes organic material.

Question 5

cellular respiration

Answer 5

a set of metabolic reactions and processes that take place in the cells of organisms to convert chemical energy from oxygen molecules or nutrients into adenosine triphosphate (ATP), and then release waste products.

Question 6

food chain

Answer 6

a hierarchical series of organisms each dependent on the next as a source of food.

Question 7

food web

Answer 7

a system of interlocking and interdependent food chains.

Question 8

trophic level

Answer 8

each of several hierarchical levels in an ecosystem, comprising organisms that share the same function in the food chain and the same nutritional relationship to the primary sources of energy.

Question 9

carbon cycle

Answer 9

the series of processes by which carbon compounds are interconverted in the environment, involving the incorporation of carbon dioxide into living tissue by photosynthesis and its return to the atmosphere through respiration, the decay of dead organisms, and the burning of fossil fuels.

Question 10

nitrogen fixing bacteria

Answer 10

Nitrogen-fixing bacteria are prokaryotic microorganisms that are capable of transforming nitrogen gas from the atmosphere into “fixed nitrogen” compounds, such as ammonia, that are usable by plants.

Question 11

nitrogen cycle

Answer 11

the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems.

Question 12

phosphorous cycle

Answer 12

the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

Question 13

ecological succession

Answer 13

the process of change in the species structure of an ecological community over time.

Question 14

primary succession

Answer 14

when new land is formed or bare rock is exposed, providing a habitat that can be colonized for the first time.

Question 15

secondary succession

Answer 15

type of ecological succession in which plants and animals recolonize a habitat after a major disturbance.

Question 16

pioneer species

Answer 16

hardy species which are the first to colonize barren environments or previously biodiverse steady-state ecosystems that have been disrupted, such as by fire

Question 17

climax community

Answer 17

An ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.