DP Biology Vocabulary - 4.1 Species, communities and ecosystems

Abiotic factors

the non-living physical and chemical attributes of a system, for example light or temperature in an environment.

Autotroph

an organism that uses solar energy or chemical energy to manufacture the organic compounds it needs as nutrients from simple inorganic compounds obtained from its environment.

Biotic factors

attributes in an ecosystem that refer to living organisms.

Chi-squared test

a statistical test of the fit between a theoretical frequency distribution and a frequency distribution of observed data for which each observation may fall into one of several classes.

Community

formed by populations of different species living together and interacting with each other.

Consumers

heterotrophs that feed on living organisms by ingestion.

Crossbreeding

when members of different species breed together.

Detritivores

heterotrophs that obtain organic nutrients from dead organisms by internal digestion.

Ecosystem

community of different species interacting with each other and with the chemical and physical factors making up the non-living environment.

Heterotroph

an organism that gets its organic nutrients by feeding on autotrophs or other heterotrophs.

Inorganic nutrients

chemical elements, compounds, and other substances necessary to sustain life processes that are not chemically carbon-based.

Interbreeding

when two members of the same species mate and produce offspring.

Mesocosm

an experimental tool that brings a small part of the natural environment under controlled conditions.

Population

a group of organisms of the same species who live in the same area at the same time.

Quadrat sampling

square or rectangular plot of land, a quadrat, marked off at random to isolate a sample and determine the percentage of vegetation and animals occurring within the marked area.

Random numbers

a number chosen by a random sampling from a table or generated by a computer.

Saprotrophs

heterotrophs that obtain organic nutrients from detritus by external digestion.

Species

groups of organisms that can potentially interbreed to produce fertile offspring.

Sustainable communities

communities that are capable of being maintained at a steady level without exhausting natural resources or causing severe ecological damage.