[13.1] food chains and energy transfer Flashcards
definition of an ecosystem
interaction of biotic and abiotic factors within an area
definition of species
a group of organisms capable of naturally reproducing to produce viable offspring
definition of habitat
- the place where an organism normally lives
- it has biotic and abiotic features which separate it from other habitats
definition of community
the different populations of species that live in a habitat
definition of decomposers
microbes, bacteria, and fungi that obtain nutrients by breaking down dead organisms and faeces
definition of detritus feeders
organisms such as earthworms which feed on small fragments of organic debris, called detritus
what non-living material is detritus made up of?
- faeces
- fallen leaves
- remains of dead organisms
definition of niche
- the interrelationship of a species with all the biotic and abiotic factors affecting it
- the role of an organism within an ecosystem / community
definition of trophic level
the position an organism occupies within a food web
definition of autotroph / producer
- able to produce organic molecules from inorganic molecules
- the first trophic level in the food chain
definition of heterotroph
- an organism unable to synthesise its own organic molecules
- must feed on organic matter
definition of primary consumer / detritivore
an organism which consumes producers / dead matter
definition of secondary consumer
an organism which feeds on primary consumers
definition of saprotroph / saprobiont
- an organism which digests its food externally then absorbs the contents
- feeds on dead or decaying matter
what is saprotrophic nutrition?
extracellular digestion via secretion of digestive enzymes which releases inorganic ions into the soil, most of which are absorbed by saprobionts