A2 Biology Unit 2 Module 3

Front 1

The maximum population size that can be maintained over a period of time in a particular habitat.

Back 1

Carrying capacity

Front 2

All the populations of different species that live in the same place at the same time, and who can interact with each other.

Back 2

Community

Front 3

A struggle between individuals for resources (like food or water) that are not present in amounts adequate to satisfy the needs of all the individuals who depend on those resources.

Back 3

Competition

Front 4

All the living organisms and all the non-living components in a specific habitat, and their interactions.

Back 4

Ecosystem

Front 5

The place where an organism or population of organisms lives.

Back 5

Habitat

Front 6

A variable that limits the rate of a particular process.

Back 6

Limiting factor

Front 7

The role that a species plays in an ecosystem.

Back 7

Niche

Front 8

All of the organisms of one species, who live in the same place at the same time, and who can breed together.

Back 8

Population

Front 9

The rate of production of new biomass by producers. It is the energy captured by their chlorophyll and used to synthesise organic molecules.

Back 9

Productivity

Front 10

A square frame used for sampling in fieldwork.

Back 10

Quadrat

Front 11

A directional change in a community of organisms over time.

Back 11

Succession

Front 12

A line taken through a habitat, which helps with systematic sampling of changes across a habitat.

Back 12

Transect

Front 13

The position at which an organism feeds in a food chain.

Back 13

Trophic level

Front 14

The non-living factors influecning an ecosystem

Back 14

Abiotic factors

Front 15

The living factors influencing an ecosystem

Back 15

Biotic factors

Front 16

Organisms that synthesise their own food from simpler substances using chemical substrates as a source of energy

Back 16

Chemoautotrophic

Front 17

In succession, the term used to decribe the final stable population that is reached under one set of environmental conditions

Back 17

Climax community

Front 18

An organism that derives energy from other organisms

Back 18

Consumer

Front 19

An organism that derives energy from breaking down dead or waste organic material

Back 19

Decomposer

Front 20

Term used to describe biomass after removal of water

Back 20

Dry mass

Front 21

A diagram showing the feeding relationships within an ecosystem. Comprises multiple food chains.

Back 21

Food web

Front 22

Competition for resources between different species in an ecosystem.

Back 22

Interspecific competition

Front 23

Competition for resources within a population.

Back 23

Intraspecific competition

Front 24

Mutualistic organisms that provide some plants with nitrates due to their ability to oxidise atmospheric nitrogen.

Back 24

Nitrogen-fixing bacteria

Front 25

An estimate of the abundance of a plant by counting the number of squares in a quadrat containing the species and expressing the result as a percentage.

Back 25

Percentage cover

Front 26

Opportunistic species that are the first to colonise newly-formed habitatssuch as volcanic islands.

Back 26

Pioneer community

Front 27

A species that obtains its food exclusively by hunting and killing other animals, usually situated at the top of food chains.

Back 27

Predator

Front 28

A species, often a primary consumer, that is frequently eaten by animals higher up the food chain.

Back 28

Prey

Front 29

Term describing the trophic level occupied by most herbivores.

Back 29

Primary consumer

Front 30

Within a food chain, describes an organism that can synthesise its own food.

Back 30

Producer

Front 31

A way of showing energy transfer in food chains by quantifying the organic material at each trophic level.

Back 31

Pyramid of biomass

Front 32

The most accurate way of displaying energy flows through food chains.

Back 32

Pyramid of energy

Front 33

A way of showing the hierarchy of food chains that reflects the population at each trophic level.

Back 33

Pyramid of numbers

Front 34

In ecology, a general approach to estimating the population size of any organism.

Back 34

Sampling

Front 35

Term describing the behaviour of detritivores.

Back 35

Saprotrophic

Front 36

In a food chain, these carnivorous or omnivorous organisms prey on primary consumers.

Back 36

Secondary consumer

Front 37

In a food chain, this trophic level is usually the first to be occupied by carnivorous predators.

Back 37

Tertiary consumer

Front 38

Term used to describe the immediate estimate of unprocessed biomass.

Back 38

Wet mass