Systems, Matter, & Energy: Vocab (UNIT 2)

Photosynthesis

The process by which plants and some other organisms convert light energy into chemical energy, using carbon dioxide and water to produce oxygen and sugar

Cellular respiration

The process by which organisms break down food (like glucose) in the presence of oxygen to produce energy, releasing carbon dioxide and water as byproducts

Producers/autotrophs

Organisms that can produce their own food from inorganic sources, like sunlight or chemicals

Consumers/heterotrophs

An organism that cannot produce its own food and must obtain it by consuming other organisms

Herbivore

An organism that primarily or exclusively feeds on plants or other photosynthetic organisms like algae

Carnivore

An animal that primarily eats other animals (meat)

Omnivore

An organism that consumes both plants and animals

Decomposer/saprotroph

Organisms that break down dead organic matter, returning nutrients to the ecosystem

Detritivore/Scavenger

• An organism that feeds on dead organic matter (detritus) for energy and nutrients

• An animal that feeds on dead organisms or parts of organisms that it did not kill itself

Detritus

Dead or decaying organic matter

Trophic level

The position an organism occupies in a food chain, indicating its source of energy and nutrients within an ecosystem

Food chain

A linear sequence of organisms where nutrients and energy are transferred from one to another as one organism consumes another

Food web

A complex, interconnected diagram that illustrates the feeding relationships within an ecosystem

Ecological pyramid

A graphical representation that illustrates the flow of energy and the relationships between organisms at different trophic levels within an ecosystem

Pyramid of Energy

Visual representation of energy flow through different trophic levels in an ecosystem

Pyramid of Numbers

A graphic representation showing the number of organisms at each trophic level in a food chain

Pyramid of Biomass

A graphic representation that shows the biomass (total mass of living organisms) at each trophic level in a food chain or food web

Gross primary productivity (GPP)

The total amount of organic matter produced by primary producers (plants and other photosynthetic organisms) in an ecosystem during a given time period

Net primary productivity (NPP)

The rate at which energy is converted into organic material by plants (or other primary producers) in an ecosystem, after accounting for the energy used by those producers for their respiration

Secondary productivity

The rate at which consumers, such as herbivores and carnivores, produce new biomass within an ecosystem

System

A group of interconnected parts that work together to form a complex whole

Open system

A system that exchanges both matter and energy within its surroundings

Closed system

A system where no matter, like air or water, can enter or leave, but energy can be exchanged

Isolated system

A system that does not exchange energy or matter with its surroundings