ESS IB Test Review ACTUAL UPDATED QUESTIONS AND CORRECT
ANSWERS
Abiotic Factor A non-living, physical factor that may influence an organism or ecosystem; i.e.
temperature, sunlight, pH, salinity, precipitation
Biochemical Oxygen Demand (BOD) A measure of the amount of dissolved oxygen required to break down the
organic material in a given volume of water through aerobic biological activity
Biodegradable Capable of being broken down by natural biological processes; i.e. the activities
of decomposer organisms
Biodiversity The amount of biological or living diversity per unit area. It includes the concepts
of species diversity, habitat diversity and genetic diversity.
Biomass/ Standing Crop The mass of organic material in organisms or ecosystems, usually per unit area.
Sometimes the term "dry weight biomass" is used where mass is measured after
the removal of water. Water is not organic material and inorganic material is
usually relatively insignificant in terms of mass.
, Biome A collection of ecosystems sharing similar climatic conditions; i.e. tundra, tropical
rainforest, desert.
Biosphere That part of the Earth inhabited by organisms, that is, the narrow zone (a few km
thick) in which plants and animals exist. It extends from the upper part of the
atmosphere (where birds, insects and wind-blown pollen may be found) down to
the deepest part of the Earth's crust to which living organisms venture.
Biotic Factor A living, biological factor that may influence an organism or ecosystem; i.e.
predation, parasitism, disease, competition.
Carrying Capacity The maximum number of species or "load" that can be sustainably supported by a
given environment.
Climax Community A community of organisms that is more or less stable, and that is in equilibrium
with natural environmental conditions such as climate; the end point of ecological
succession.
Community A group of populations living and interacting with each other in a common
habitat.
Competition A common demand by 2 or more organisms upon limited supply of a resource; i.e.
food, water, light, space, mates, nesting sites. It may be intraspecific or
interspecific.
Correlation A measure of the association between 2 variables. If 2 variables tend to move up
or down together, they are said to be positively correlated. If they tend to move in
opposite directions, they are said to be negatively correlated.
Crude Birth Rate The number of births per thousand individuals in a population per year.
Crude Death Rate The number of deaths per thousand individuals in a population per year.
Demographic Translation A general model describing the changing levels of fertility and mortality in a
human population over time. It was developed with reference to the transition
experienced as developed countries (i.e. those of North America, Europe,
Australia) passed through the processes of industrialization and urbanization.
Diversity A generic term for heterogeneity. The scientific meaning of the diversity becomes
clease from the context in which it is used; it may refer to heterogeneity of species
of habitat, or to genetic heterogeneity.
ANSWERS
Abiotic Factor A non-living, physical factor that may influence an organism or ecosystem; i.e.
temperature, sunlight, pH, salinity, precipitation
Biochemical Oxygen Demand (BOD) A measure of the amount of dissolved oxygen required to break down the
organic material in a given volume of water through aerobic biological activity
Biodegradable Capable of being broken down by natural biological processes; i.e. the activities
of decomposer organisms
Biodiversity The amount of biological or living diversity per unit area. It includes the concepts
of species diversity, habitat diversity and genetic diversity.
Biomass/ Standing Crop The mass of organic material in organisms or ecosystems, usually per unit area.
Sometimes the term "dry weight biomass" is used where mass is measured after
the removal of water. Water is not organic material and inorganic material is
usually relatively insignificant in terms of mass.
, Biome A collection of ecosystems sharing similar climatic conditions; i.e. tundra, tropical
rainforest, desert.
Biosphere That part of the Earth inhabited by organisms, that is, the narrow zone (a few km
thick) in which plants and animals exist. It extends from the upper part of the
atmosphere (where birds, insects and wind-blown pollen may be found) down to
the deepest part of the Earth's crust to which living organisms venture.
Biotic Factor A living, biological factor that may influence an organism or ecosystem; i.e.
predation, parasitism, disease, competition.
Carrying Capacity The maximum number of species or "load" that can be sustainably supported by a
given environment.
Climax Community A community of organisms that is more or less stable, and that is in equilibrium
with natural environmental conditions such as climate; the end point of ecological
succession.
Community A group of populations living and interacting with each other in a common
habitat.
Competition A common demand by 2 or more organisms upon limited supply of a resource; i.e.
food, water, light, space, mates, nesting sites. It may be intraspecific or
interspecific.
Correlation A measure of the association between 2 variables. If 2 variables tend to move up
or down together, they are said to be positively correlated. If they tend to move in
opposite directions, they are said to be negatively correlated.
Crude Birth Rate The number of births per thousand individuals in a population per year.
Crude Death Rate The number of deaths per thousand individuals in a population per year.
Demographic Translation A general model describing the changing levels of fertility and mortality in a
human population over time. It was developed with reference to the transition
experienced as developed countries (i.e. those of North America, Europe,
Australia) passed through the processes of industrialization and urbanization.
Diversity A generic term for heterogeneity. The scientific meaning of the diversity becomes
clease from the context in which it is used; it may refer to heterogeneity of species
of habitat, or to genetic heterogeneity.
