4.1 Species, communities and ecosystems Flashcards
what are species?
species are a group of organisms that can potentially interbreed to produce fertile offspring
define a population
a population is a group of organisms of the same species living in the same area at the same time
define community
comprises populations of different species living and interacting with each other in an area
define ecosystem
comprises a community interacting with its abiotic (non-living) environment.
define autotrophic
it is an organism that synthesizes organic carbon compounds from inorganic nutrients (such as carbon dioxide and mineral ions) using an external energy source (sunlight)
-inorganic nutrients are obtained from the abiotic environment.
define heterotrophic
it is an organism that obtains organic carbon compounds from other organisms.
define saprotrophs
(or decomposer) is a heterotroph that lives on or in non-living organic matter, secreting digestive enzymes, and absorbing digested molecules.
- saprotrophs digest nutrients externally
- for example bacteria and fungi
define consumer
a consumer is a heterotroph that ingests living or recently killed organisms.
-consumers digest nutrients internally
define detritivores
is a heterotroph that ingests non-living organic nutrients (detritus).
-detrivores digest nutrients internally.
what is mixotrophic? and give one example
organisms that are not exclusively autotrophic or heterotrophic are mixotrophic. one example is Euglena gracilis has chloroplasts and carries out photosynthesis where there is sufficient light, but can also feed on detritus or smaller organisms by endocytosis.
how unicellular and multicellular consumers take the food in? give an example of each.
unicellular consumers such as paramecium take the food in by endocytosis and digest it inside vacuoles. multicellular consumers such as lions take food into their digestive system by swallowing it.
what is an omnivore?
is an animal that is both a herbivore and carnivore.
