Ecology Definitions Ecology the study of the relationships between organisms and their environment
Ecosystem consists of all the factors that affect the chances of survival of an organism (living and non-living factors) Biotic Abiotic living factors non-living factors (rocks, soil, water, climate, temperature) the place where an individual organism is living at a particular time (living place)
Habitat
Adaptation a characteristic which enables an organism to survive in the
environment
Biosphere the region of the Earths surface (both land and water) and immediate atmosphere which can support any living organism Community all species of organisms living together in a particular place Population the number of a single species living in a particular place Density the total number of individuals of a species per unit area the particular part of the habitat that a species uses and the way it uses it, the role of an organism
Niche
Herbivore an animal that eats only plants (1st order consumer, eg: horse, antelope,
kangaroo)
Carnivore an animal that eats meat (2nd, 3rd etc order consumer, eg: lion, wolf, fox, Tasmanian Devil)
Omnivore an animal that eats both plants and meat (bear, pig)
Frugivore
an animal that feeds primarily on fruit (fruit bat, possum)
Insectivore
an animal that feeds mostly on insects (ant eater,
numbat)
Autotroph
an organism that manufactures its own food by photosynthesis (all green plants)
Photosynthesis 6CO2 + 6H2O Sun C6H12O6 + 6O2
Heterotroph an organism that eats other organisms as it cannot manufacture its own food (all animals) Saprotroph (Decomposer) an organism which decomposes plant or animal remains (bacteria and fungi) Scavenger animals that eat dead plants & dead animals
(vulture, fly, cockroach)
Symbiosis
a beneficial relationship between 2 organisms (eg: mutualism, commensalism)
Mutualism a very close relationship between 2 organisms (one or both may die if parted), both organisms benefit Commensalism a relationship between 2 organisms where one or both benefit from the partnership (but each could survive without the other) Predation a relationship where organisms only come together when one (the predator) is intent on killing the other (the prey) for food
Parasitism a close relationship where one organism (the host) is harmed but the other organism (the parasite) benefits, a
parasite can live on the outside (ectoparasite) or inside (endoparasite) the host Food Chain a chain of organisms existing in any natural community through which energy is transferred Food Web a group of food chains in a community Trophic Level the energy level of each organism in a food chain (eg: plants are on T1, herbivores are on T2, carnivores are on T3 or T4)
