IB ESS Review
model - Answer-a simplified description designed to show the structure or working of an object, system
or concept.
open system - Answer-type ***** in which both matter and energy are exchanged with its surroundings
closed system - Answer-type ****** in which energy but not matter is exchanged with its surroundings
Gaia hypothesis - Answer-developed by James Lovelock, compares the Earth to a living organism in
which feedback mechanisms maintain equilibrium
isolated system - Answer-type ******** in which neither energy nor matter is exchanged with its
surroundings.
system - Answer-an assemblage of parts and their relationships between them, which together
constitute an entity or whole
positive feedback - Answer-that tends to amplify or increase change leads to exponential deviation away
from an equilibrium
negative feedback - Answer-that tends to damp down, neutralize or counteract any deviation from an
equilibrium, promoting stability
, biosphere - Answer-The part of the earth inhabited by organisms, that is, a narrow zone (a few
kilometers in thickness) in which plants and animals exist. It extends from the upper part of the
atmosphere down to the deepest part of the Earth's crust to which living organisms venture.
steady state equilibrium - Answer-characteristics of open systems where there are continuous inputs
and outputs of energy and matter but the system as a whole remains more or less constant.
society - Answer-arbitrary group of individuals who share some common characteristic such as
geographical location, cultural background, historical influence, religious perspective, value system and
so on.
entropy - Answer-a measure of the amount of disorder, chaos or randomness in a system the greater
the disorder the higher the level of this.
abiotic factors - Answer-non living factor that may influence an ecosystem. Ex: temperature, pH, Salinity
biotic factors - Answer-living biological factors that may influence an organism or ecosystem. Ex:
Predation disease, competition
Principle of Competitive exclusion - Answer-2 species competing for the same resources cannot coexist
in the same community.
Pyramid of Productivity - Answer-flow of energy through a trophic level, only 10% of pervious level
available to the next level. Measured in g/m2
Gross Productivity (GP) - Answer-total gain in energy or biomass per unit area per unit time. Could be
through primary producers or absorption in consumers.
Net Primary Productivity (NPP) - Answer-GP-respiration= gain in energy per unit area per unit of time
after allowing for respiratory losses.
model - Answer-a simplified description designed to show the structure or working of an object, system
or concept.
open system - Answer-type ***** in which both matter and energy are exchanged with its surroundings
closed system - Answer-type ****** in which energy but not matter is exchanged with its surroundings
Gaia hypothesis - Answer-developed by James Lovelock, compares the Earth to a living organism in
which feedback mechanisms maintain equilibrium
isolated system - Answer-type ******** in which neither energy nor matter is exchanged with its
surroundings.
system - Answer-an assemblage of parts and their relationships between them, which together
constitute an entity or whole
positive feedback - Answer-that tends to amplify or increase change leads to exponential deviation away
from an equilibrium
negative feedback - Answer-that tends to damp down, neutralize or counteract any deviation from an
equilibrium, promoting stability
, biosphere - Answer-The part of the earth inhabited by organisms, that is, a narrow zone (a few
kilometers in thickness) in which plants and animals exist. It extends from the upper part of the
atmosphere down to the deepest part of the Earth's crust to which living organisms venture.
steady state equilibrium - Answer-characteristics of open systems where there are continuous inputs
and outputs of energy and matter but the system as a whole remains more or less constant.
society - Answer-arbitrary group of individuals who share some common characteristic such as
geographical location, cultural background, historical influence, religious perspective, value system and
so on.
entropy - Answer-a measure of the amount of disorder, chaos or randomness in a system the greater
the disorder the higher the level of this.
abiotic factors - Answer-non living factor that may influence an ecosystem. Ex: temperature, pH, Salinity
biotic factors - Answer-living biological factors that may influence an organism or ecosystem. Ex:
Predation disease, competition
Principle of Competitive exclusion - Answer-2 species competing for the same resources cannot coexist
in the same community.
Pyramid of Productivity - Answer-flow of energy through a trophic level, only 10% of pervious level
available to the next level. Measured in g/m2
Gross Productivity (GP) - Answer-total gain in energy or biomass per unit area per unit time. Could be
through primary producers or absorption in consumers.
Net Primary Productivity (NPP) - Answer-GP-respiration= gain in energy per unit area per unit of time
after allowing for respiratory losses.
