ESS IB EXAM REVIEW QUESTIONS
WITH COMPLETE SOLUTIONS 2024
biotic factors - ANSWERSliving parts of an ecosystem
abiotic factors - ANSWERSNonliving components of environment.
species - ANSWERSA group of similar organisms that can breed and produce fertile offspring.
population - ANSWERSA group of individuals that belong to the same species and live in the same area
habitat - ANSWERSPlace where an organism lives
niche - ANSWERSDescribes the interactions a species has with the abiotic and biotic factors in its
environment
fundamental niche - ANSWERSThe niche species could potentially occupy.
realized niche - ANSWERSThe niche species actually occupies.
biome - ANSWERSA group of ecosystems that share similar climates and typical organisms
ecosystem - ANSWERSA biological community of interacting organisms and their physical environment.
community - ANSWERSAll the different populations that live together in an area
Respiration equation - ANSWERSC6H12O6 + 6O2 --→ 6CO2 + 6H20 + Energy
,Photosynthesis equation - ANSWERS6CO2 + 6H2O --> light energy --> C6H12O6 + 6O2
biomass - ANSWERStotal amount of living tissue within a given trophic level
Gross Productivity - ANSWERSThe total gain in energy or biomass per unit area per unit time. GPP -->
Producers, GSP --> consumers
Net productivity - ANSWERSthe gain in energy or biomass per unit area per unit time that remains after
deductions due to respiration. NPP --> producers, NSP --> consumers
1st law of thermodynamics - ANSWERSEnergy cannot be created or destroyed
2nd law of thermodynamics - ANSWERSThe principle whereby every energy transfer or transformation
increases the entropy of the universe. Ordered forms of energy are at least partly converted to heat, and
in spontaneous reactions, the free energy of the system also decreases.
Positive Feedback - ANSWERSFeedback that tends to magnify a process or increase its output.
negative feedback - ANSWERSa mechanism of response in which a stimulus initiates reactions that
reduce the stimulus
Open system - ANSWERSsystem where matter and energy is exchanged
closed system - ANSWERSsystem where only energy is exchanged
isolated system - ANSWERSsystem where neither energy nor matter is exchanged
Steady-state equilibrium - ANSWERSThe condition of an open system in which there are no changes over
the longer term, but in which there may be oscillations in the very short term. There are continuing
inputs and outputs of matter and energy, but the system as a whole remains in a more or less constant
state.
, static equilibrium - ANSWERSNo change over time; when the state of equilibrium is distributed, the
system adapts a new equilibrium. Cannot occur in living systems.
stable equilibrium - ANSWERSThe condition of a system in which there is a tendency for it to return to a
previous equilibrium condition following disturbance.
unstable equilibrium - ANSWERSsystem returns to a new equilibrium after disturbances
transfers - ANSWERSMovement of material and energy
transformations - ANSWERS- Matter to matter
- Energy to energy
- Matter to energy
- Energy to matter
Gaia Hypothesis - ANSWERSThe theory that the Earth is best understood as a living entity that acts to
maintain its own existence
food chain - ANSWERSshows the flow of energy from one organism to another and another
food web - ANSWERSa system of interlocking and interdependent food chains.
trophic level - ANSWERSEach step in a food chain or food web
producers - ANSWERSOrganisms that make their own food
consumers - ANSWERSAn organism that obtains energy and nutrients by feeding on other organisms or
their remains.
Decomposer - ANSWERSAn organism that breaks down wastes and dead organisms
WITH COMPLETE SOLUTIONS 2024
biotic factors - ANSWERSliving parts of an ecosystem
abiotic factors - ANSWERSNonliving components of environment.
species - ANSWERSA group of similar organisms that can breed and produce fertile offspring.
population - ANSWERSA group of individuals that belong to the same species and live in the same area
habitat - ANSWERSPlace where an organism lives
niche - ANSWERSDescribes the interactions a species has with the abiotic and biotic factors in its
environment
fundamental niche - ANSWERSThe niche species could potentially occupy.
realized niche - ANSWERSThe niche species actually occupies.
biome - ANSWERSA group of ecosystems that share similar climates and typical organisms
ecosystem - ANSWERSA biological community of interacting organisms and their physical environment.
community - ANSWERSAll the different populations that live together in an area
Respiration equation - ANSWERSC6H12O6 + 6O2 --→ 6CO2 + 6H20 + Energy
,Photosynthesis equation - ANSWERS6CO2 + 6H2O --> light energy --> C6H12O6 + 6O2
biomass - ANSWERStotal amount of living tissue within a given trophic level
Gross Productivity - ANSWERSThe total gain in energy or biomass per unit area per unit time. GPP -->
Producers, GSP --> consumers
Net productivity - ANSWERSthe gain in energy or biomass per unit area per unit time that remains after
deductions due to respiration. NPP --> producers, NSP --> consumers
1st law of thermodynamics - ANSWERSEnergy cannot be created or destroyed
2nd law of thermodynamics - ANSWERSThe principle whereby every energy transfer or transformation
increases the entropy of the universe. Ordered forms of energy are at least partly converted to heat, and
in spontaneous reactions, the free energy of the system also decreases.
Positive Feedback - ANSWERSFeedback that tends to magnify a process or increase its output.
negative feedback - ANSWERSa mechanism of response in which a stimulus initiates reactions that
reduce the stimulus
Open system - ANSWERSsystem where matter and energy is exchanged
closed system - ANSWERSsystem where only energy is exchanged
isolated system - ANSWERSsystem where neither energy nor matter is exchanged
Steady-state equilibrium - ANSWERSThe condition of an open system in which there are no changes over
the longer term, but in which there may be oscillations in the very short term. There are continuing
inputs and outputs of matter and energy, but the system as a whole remains in a more or less constant
state.
, static equilibrium - ANSWERSNo change over time; when the state of equilibrium is distributed, the
system adapts a new equilibrium. Cannot occur in living systems.
stable equilibrium - ANSWERSThe condition of a system in which there is a tendency for it to return to a
previous equilibrium condition following disturbance.
unstable equilibrium - ANSWERSsystem returns to a new equilibrium after disturbances
transfers - ANSWERSMovement of material and energy
transformations - ANSWERS- Matter to matter
- Energy to energy
- Matter to energy
- Energy to matter
Gaia Hypothesis - ANSWERSThe theory that the Earth is best understood as a living entity that acts to
maintain its own existence
food chain - ANSWERSshows the flow of energy from one organism to another and another
food web - ANSWERSa system of interlocking and interdependent food chains.
trophic level - ANSWERSEach step in a food chain or food web
producers - ANSWERSOrganisms that make their own food
consumers - ANSWERSAn organism that obtains energy and nutrients by feeding on other organisms or
their remains.
Decomposer - ANSWERSAn organism that breaks down wastes and dead organisms
