A2 Edexcel Biology Topic 5 Definitions

Front 1

Biosphere

Back 1

Part of the earth and its atmosphere inhabited by living organisms

Front 2

Abiotic

Back 2

Physical + chemical factors - non living

Front 3

Biotic

Back 3

Factors determined by organisms - living

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Community

Back 4

Various populations sharing a habitat

Front 5

Interspecific competition

Back 5

Competition between species

Front 6

Intraspecific competition

Back 6

Competition within species

Front 7

Anthropogenic factors

Back 7

Factors arising from human activity

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Succession

Back 8

Process of a community changing over time

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Producer/autotroph

Back 9

Organism that can make it's own organic compounds from inorganic compounds

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Herbivore/primary consumer

Back 10

Consumes plant material

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Carnivore/secondary consumer

Back 11

Consumes herbivores

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Tertiary consumer

Back 12

Eat other carnivores

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Secondary succession

Back 13

Where an existing community has been cleared this succession occurs

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Deflected succession

Back 14

A community that remains stable because human activity prevents succession

Front 15

Primary productivity of an ecosystem

Back 15

Rate at which energy is incorporated into inorganic molecules in an ecosystem

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Chemosynthetic

Back 16

Make organic molecules using energy released from chemical reactions

Front 17

Omnivores

Back 17

Animals that eat plants + other animals

Front 18

Trophic level

Back 18

Position a species occupies on a food chain

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Detritivores

Back 19

Primary consumers that feed on dead organic material

Front 20

Decomposers

Back 20

Species of bacteria and fungi that feed on dead remains of organisms and animal faeces

Front 21

Gross primary productivity (GPP)

Back 21

Rate at which energy is incorporated into organic molecules by an ecosystem

Front 22

Net primary productivity (NPP)

Back 22

Rate at which energy is transferred into the new organelles that make up new plant biomass

Front 23

NPP =

Back 23

NPP = GPP - R (respiration)

Front 24

Phenology

Back 24

Study of seasonal events in the lives of animals and plants

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Speciation

Back 25

Formation of new species

Front 26

Reproductive isolation

Back 26

2 populations that are unable to interbreed to produce fertile offspring

Front 27

Hydrolysis

Back 27

Splitting of water into hydrogen + oxygen using sunlight

Front 28

Exons

Back 28

Coding regions in DNA

Front 29

Introns

Back 29

Non-coding regions in DNA

Front 30

Short tandem repeats

Back 30

Sequence of repeated bases within introns