IB Biology: Transfer of Energy and Matter

Vocabulary flashcards covering key concepts from the IB Biology notes on energy and matter transfer in ecosystems.

Ecosystem

A community of organisms plus their abiotic environment.

Open systems

Systems that exchange both energy and matter with their surroundings.

Producers

Organisms that capture energy from the sun or chemicals to create energy-rich organic compounds.

Photosynthesis

The process by which producers convert sunlight into chemical energy.

Food chain

A linear sequence showing how energy and matter flow from producers to consumers.

Decomposers

Organisms that recycle nutrients by breaking down dead organisms.

Saprotrophs

Organisms that perform external digestion to absorb soluble products from dead material.

Detritivores

Organisms that ingest detritus and digest it internally.

Primary production (GPP)

The total carbon fixed by producers during photosynthesis.

Net primary production (NPP)

GPP minus the carbon used during respiration; the energy available to consumers.

Energy transfer efficiency

The percentage of energy that is transferred from one trophic level to the next; about 10% on average.

The Carbon Cycle

The process by which carbon cycles continuously through abiotic and biotic compartments of ecosystems.

Keeling Curve

A graph that shows the rising concentration of CO₂ in the atmosphere since 1959.

Heterotrophs

Organisms that obtain organic compounds from eating other organisms.

Biomass

The total mass of living matter in a given area, usually expressed in grams per square meter.

Fluxes in carbon cycle

The movement of carbon through processes like photosynthesis, respiration, and decomposition.

Apex predators

Top-level consumers with few or no natural predators, requiring large territories.

Energy pyramids

Visual representations of energy loss and biomass distribution at each trophic level.

Respiration

The process by which organisms convert carbohydrates into energy, releasing CO₂ and heat.