EEB 3407: Week 3 Lecture Questions with
Correct Answers
Ecosystem
A set of interacting organisms and abiotic/nonliving factors; ecosystem ecology focuses on
flows of energy and nutrients.
Ecosystem functioning
All chemical, physical, and biological processes happening in an ecosystem, such as
productivity, decomposition, and nutrient cycling.
Ecosystem services
Ecosystem functions that directly benefit human well-being.
Ecosystem functioning vs. ecosystem services
Functioning includes all ecosystem processes; services are the subset of those processes that
benefit humans.
Carbon cycle
The movement of carbon among the atmosphere, organisms, soils, oceans, and fossil carbon
pools.
Why is carbon important?
Carbon is a major building block of life and carbon compounds are important for energy
transfer.
Photosynthesis
Plants use CO2, water, and energy to make carbon compounds and oxygen.
, Photosynthesis equation
6CO2 + 6H2O + energy → C6H12O6 + 6O2
Respiration
Organisms break down carbon compounds, releasing energy, CO2, and water.
Respiration equation
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
Climate change and the carbon cycle
Human activities alter carbon storage and fluxes, increasing atmospheric greenhouse gases
and changing temperature, precipitation, and disturbance patterns.
Nitrogen
An essential element for proteins, DNA, RNA, and chlorophyll; often limiting for primary
production.
Atmospheric nitrogen/N2
The most abundant form of nitrogen in the atmosphere, but mostly unusable by organisms
because it is triple-bonded.
Reactive nitrogen
Biologically usable forms of nitrogen, such as nitrate, nitrite, and ammonium.
Nitrate
NO3-, a reactive nitrogen form usable by organisms.
Nitrite
Correct Answers
Ecosystem
A set of interacting organisms and abiotic/nonliving factors; ecosystem ecology focuses on
flows of energy and nutrients.
Ecosystem functioning
All chemical, physical, and biological processes happening in an ecosystem, such as
productivity, decomposition, and nutrient cycling.
Ecosystem services
Ecosystem functions that directly benefit human well-being.
Ecosystem functioning vs. ecosystem services
Functioning includes all ecosystem processes; services are the subset of those processes that
benefit humans.
Carbon cycle
The movement of carbon among the atmosphere, organisms, soils, oceans, and fossil carbon
pools.
Why is carbon important?
Carbon is a major building block of life and carbon compounds are important for energy
transfer.
Photosynthesis
Plants use CO2, water, and energy to make carbon compounds and oxygen.
, Photosynthesis equation
6CO2 + 6H2O + energy → C6H12O6 + 6O2
Respiration
Organisms break down carbon compounds, releasing energy, CO2, and water.
Respiration equation
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy
Climate change and the carbon cycle
Human activities alter carbon storage and fluxes, increasing atmospheric greenhouse gases
and changing temperature, precipitation, and disturbance patterns.
Nitrogen
An essential element for proteins, DNA, RNA, and chlorophyll; often limiting for primary
production.
Atmospheric nitrogen/N2
The most abundant form of nitrogen in the atmosphere, but mostly unusable by organisms
because it is triple-bonded.
Reactive nitrogen
Biologically usable forms of nitrogen, such as nitrate, nitrite, and ammonium.
Nitrate
NO3-, a reactive nitrogen form usable by organisms.
Nitrite
