Chapter 58-Dynamics of Ecosystems

Question 1

Ecosystem

Answer 1

-includes all the organisms that live in one place (biotic) plus the abiotic environment in which they live

Question 2

Biogeochemical cycle

Answer 2

• chemicals moving through ecosystems
• biotic and abiotic processes
• cross boundaries of ecosystems

Question 3

carbon fixation

Answer 3

-metabolic reactions that make nongaseous compounds from gaseous ones

Question 4

Methanogenss

Answer 4

-produce methane by anaerobic cellular respiration

Question 5

Nitrogen cycle

Answer 5

• nitrogen is a component of all proteins and nucleic acids
• inorganic
• most plants and animals cannot use N2 the gas

Question 6

Nitrogen fixation

Answer 6

synthesis of nitrogen containing compounds from N2

Question 7

Nitrification

Answer 7

N2-NH3-NO3-

Question 8

Denitrification

Answer 8

-NO3- – N2

Question 9

Phosphorous cycle

Answer 9

• required by all organisms

- plants and algae use free inorganic phosphorous, animals eat plants to obtain their phosphorous

Question 10

Limiting nutrient

Answer 10

• weak link in an ecosystem, shortest supply

- can be nitrogen and phosphorous

Question 11

Energy exists as..

Answer 11

• light
• chemical (bond energy)
• motion
• heat

Question 12

Productivity

Answer 12

rate at which the organisms in the trophic level collectively synthesize new organic matter

Question 13

Gross primary productivity

Answer 13

raw rate at which primary producers sythesize new organic matter and store energy

Question 14

Net primary productivity

Answer 14

the GPP less the respiration of the primary producers

Question 15

Breakdown of energy usage in organisms (percentage)

Answer 15

50% of chemical bond energy is not assimilated and is egested in feces

• 33% used for cellular respiration
• 17% converted into biomass

Question 16

Amount of chemical bond energy available to a trophic level over time

Answer 16

10% of that available to the preceding level of the same period of time