Ib Ess Glossary - Topic 1 And 2

Front 1

Abiotic factor

Back 1

A non-living, physical factor that may influence an organism or ecosystem.

Hint 1

For example, temperature, sunlight, pH, salinity, precipitation.

Front 2

Biodiversity

Back 2

The amount of biological or living diversity per unit area. It includes the concepts of species diversity, habitat diversity and genetic diversity.

Front 3

Biomass

Back 3

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.

Hint 3

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.

Front 4

Biome

Back 4

A collection of ecosystems sharing similar climatic conditions; for example, tundra, tropical rainforest, desert.

Front 5

Biosphere

Back 5

That part of the Earth inhabited by organisms, that is, the narrow zone (a few kilometres in thickness) in which plants and animals exist.

Hint 5

It extends from the upper part of the atmosphere (where birds, insects and windblown pollen may be found) down to the deepest part of the Earth's crust to which living organisms venture.

Front 6

Biotic factor

Back 6

A living, biological factor that may influence an organism or ecosystem.

Hint 6

For example, predation, parasitism, disease, competition.

Front 7

Carrying capacity

Back 7

The maximum number of a species or "load" that can be sustainably supported by a given environment.

Front 8

Climax community

Back 8

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.

Hint 8

Front 9

Community

Back 9

A group of populations living and interacting with each other in a common habitat.

Front 10

Competition

Back 10

A common demand by two or more organisms upon a limited supply of a resource

Hint 10

For example, food, water, light, space, mates, nesting sites.
It maybe infraspecific or interspecific.

Front 11

Correlation

Back 11

A measure of the association between two variables.

Hint 11

If two 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.

Front 12

Diversity

Back 12

A genetic term for heterogeneity. The scientific meaning of diversity becomes clear from the context in which it is used; it may refer to heterogeneity of species or habitat, or to genetic heterogeneity.

Front 13

Genetic diversity

Back 13

The range of genetic material present in a gene pool or population of a species.

Front 14

Habitat diversity

Back 14

The range of different habitats or number of ecological niches per unit area in an ecosystem, community, or biome.

Front 15

Diversity index

Back 15

A numerical measure of species diversity that is derived from both the number of species (variety) and their proportional abundance.

Front 16

Species diversity

Back 16

The variety of species per unit area. This includes both the number of species preset and their relative abundance.

Front 17

Ecosystem

Back 17

A community of interdependent organisms and the physical environment they inhabit.

Front 18

Entropy

Back 18

A measure of the amount of disorder, chaos, or randomness in a system; the greater the disorder, the higher the level of entropy.

Front 19

Environmental impact assessment (EIA)

Back 19

A method of detailed survey required, in many countries, before a major development.

Front 20

Equilibrium

Back 20

A state of balance among the components of a system.

Front 21

Feedback

Back 21

The return of part of the output from a system as input, so as to affect succeeding outputs.

Front 22

Negative feedback

Back 22

Feedback that tends to damp down, neutralise or counteract any deviation from an equilibrium, and promotes stability.

Front 23

Positive feedback

Back 23

Feedback that amplifies or increases change; it leads to exponential deviation away from an equilibrium.

Front 24

Gaia

Back 24

The Gaia hypothesis (developed by James Lovelock and named after an ancient Greek Earth goddess) compares the Earth to a living organism in which feedback mechanisms maintain equilibrium.

Front 25

Habitat

Back 25

The environment in which a species normally lives.

Front 26

K-strategist

Back 26

Species that usually concentrate their reproductive investment in a small number of offspring, thus increasing their survival rate and adapting them for living in long-term climax communities.

Hint 26

Like elephants, humans, whales.

Front 27

R-strategist

Back 27

Species that tend to spread their reproductive investment among a large number of offspring so that they are well adapted to colonise new habitats rapidly and make opportunistic use of short-lived resources.

Hint 27

Like house flies, mosquitos, cockroaches.

Front 28

Latitude

Back 28

The angular distance from the equator (that is, north or south of it) as measured from the centre of the Earth (usually in degrees).

Front 29

LEDC

Back 29

Less economically developed country: a country with low to moderate industrialisation and low to moderate average GNP per capita.

Front 30

MEDC

Back 30

More economically developed country: a highly industrialised country with a high average GNP per capita.

Front 31

Model

Back 31

A simplified description designed to show the structure or workings of an object, system or concept.

Front 32

Mutualism

Back 32

A relationship between individuals of two or more species in which all benefit and none suffer.

Front 33

Niche

Back 33

A species' share of a habitat and the resources in it. An organism's ecological niche depends not only on where it lives but also on what it does.

Hint 33

The niche is a complete description of a species - where, when, and how it lives. Two species cannot share the same niche. Species with overlapping niches will compete with each other.

Front 34

Parasitism

Back 34

A relationship between two species in which one species (the parasite) lives in or on another (the host), gaining all or much (in the case of a partial parasite) of its food from it.

Hint 34

For example, a mosquito.

Front 35

Population

Back 35

A group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.

Front 36

Gross productivity (GP)

Back 36

The total energy or biomass gained per unit area per unit time, which would be through photosynthesis in primary producers or absorption/feeding in consumers.

Front 37

Gross primary productivity (GPP)

Back 37

The total energy or biomass gained by producers per unit area per unit time, through photosynthesis.

Front 38

Gross secondary productivity (GSP)

Back 38

The total energy or biomass gained by consumers per unit area per unit time, through feeding or absorption.

Front 39

Net productivity (NP)

Back 39

The energy or biomass gained per unit area per unit time remaining after allowing for respiratory losses.

Front 40

Net primary productivity (NPP)

Back 40

The energy or biomass gained by producers per unit area per unit time remaining after allowing for respiratory losses.

Front 41

Net secondary productivity (NSP)

Back 41

The energy or biomass gained by consumers per unit are per unit time remaining after allowing for respiratory losses.

Front 42

Primary productivity

Back 42

The energy or biomass gained by producers per unit area per unit time.

Front 43

Secondary productivity

Back 43

The energy or biomass gained by consumers per unit area per unit time, through feeding and absorption.

Front 44

Sere

Back 44

The set of communities that succeed one another over the course of succession at a given location.

Front 45

Society

Back 45

An arbitrary group of individuals who share some common characteristics such as geographical location, cultural background, historical timeframe, religious perspective, value system, and so on.

Front 46

Stable equilibrium

Back 46

The condition of a system in which there is a tendency for it to return to a previous equilibrium condition following disturbance.

Front 47

Steady-state equilibrium

Back 47

The condition of an open system in which there are no changed 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.

Hint 47

For example, a climax ecosystem.

Front 48

Succession

Back 48

The directional change in a community of organisms over time.

Front 49

System

Back 49

An assemblage of parts and the relationships between them, which together constitute an entity or whole.

Front 50

Closed system

Back 50

A system in which energy, but not matter, is exchanged with its surroundings.

Front 51

Isolated system

Back 51

A system that exchanged neither matter nor energy with its surroundings.

Front 52

Open system

Back 52

A system in which both matter and energy are exchanged with its surroundings.

Hint 52

For example, natural ecosystems.

Front 53

Trophic level

Back 53

The position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains.

Front 54

Zonation

Back 54

The directional change in a community of organisms over a distance.

Hint 54

The arrangement or patterning of plant communities or ecosystems into parallel or sub-parallel bands in response to change, over a distance, in some environmental factor. The main biomes display donation in relation to latitude and climate. Plant communities may also display donation with altitude on a mountain, or around the edge of a pond in relation to soil moisture.