10 important definitions Flashcards
define: ECOLOGY
the study of the relationship andinteractions between livingorganisms and their environment
define:Organism
an individual living system such as an animal, plant ormicroorganism that is capable of reproduction, growth,and maintenance
define:Environment
the physical, chemical and biological conditions of theregion in which the organism lives
define:Biosphere
the whole of the region of the Earth’s surface(lithosphere), the sea (hydrosphere), and the air(atmosphere) that is inhabited by living organisms
define:Ecosystem
- a unit of the biosphere in which organisms interact witheach other and the non-living environment
define: biotic factors
living components of theenvironment- e.g. plants, animals,microorganisms, etc.
define: abiotic factors
non-living components ofthe environment- e.g. temperature, sunlight,soil, topography, wind,moisture, minerals, etc.
define: niche
the place/role occupied by an organism in its environment
define:Producers (Autotrophs)
mostly green plants that can produce their own food usingphotosynthesis- some microorganisms (including bacteria) can also make their ownfood
define: Consumers (Heterotrophs)
cannot make their own food, must eat other things- are further classified based on what they eat
define: Decomposers & Detrivores
eat dead organic matterreturning basic substances back to the soil
define: herbivores
eat only plants- are called primary (1o) consumers- exist at the first trophic level in a food chain, food web orfood pyramid
define: carnivores
eat only animal material- are secondary (2o) or tertiary (3o) consumers- exist at the second or the third trophic level in a food chain,food web or food pyramid
define: Omnivore
eat only animal material- are secondary (2o) or tertiary (3o) consumers- exist at the second or the third trophic level in a food chain,food web or food pyramid
define: food chain-benefeitsproblem
a very simple model ofecosysteminteractionsBenefit: Show whichanimals are present inthe ecosystem andwho’s eating who in a“linear” fashionProblem: Food chainsare usually anoversimplification ofwhat’s happening inthe ecosystem
define: food websbenefietproblem
a series of interconnectedfood chainsBenefit: shows morecomplex (and thus morerealistic) interactionsbetween organismsProblem: Don’t shownumerical information ofany kind.
define:pyramid of numbers
- shows how many animalsare at each trophic level- numbers usually decreaseat each levelBenefits: Easy to countanimals in the ecosystemProblem: Pyramids ofnumbers treat all animalsequally regardless ofsize differences.!
define: pyramid of biomassbenefitproblem
defn: biomass- the mass of dry mattercontained in a group ofliving thingsBenefit: Show the total massof orgainisms at eachtrophic level.Problem: Implies that equalmasses of different foodsprovide the same amountof energy
define: pyramid of numbers
show the amount of foodenergy available at eachtrophic level- never inverted - less energyavailable at eachsuccessive level- energy not lost, simplyconverted into otherforms- 90% lost at each level
