4.1 Species, Community and ecosystems Flashcards
define species
a group of organisms that can potentially interbred to produce fertile offspring NB it does not include organisms that can reproduce asexually or are extinict
define population
groups of organisms of the same species living in teh same area at teh same time
define community
group of population that live within a given area and interact
define habitat
the environment in which a species lives e.g. an oak woodland or freshwater pond
define ecosystem
a community adn its interactions wit teh abiotic environment types e..g desert, rainforest
define abiotic
the non-living chemical and physical factors in an en environemnt e.g. temperature, PH, Salinity, humidity and wind
define biotic
the living components of na environement which affect an ecosystem e.g. pathogens, competition, predation, decomposers
define nutrient
a nutrient is a substance (found in food) used by organisms to survive, grwo, and reproduce. There are 6 major nutrients (carbohydrates, lipids, proteins, vitamins, minerals and water)
define autotroph
organisms that syntehsie their own organic molecules from simple inorganic substance (e.g. CO2 and nitrate) energy is derieved from sunlight (photosynthesis)
define heterotroph
obtain their organic molecules from otehr organisms using digestive enzymes
waht is a mixotroph
organisms that use both authotrophig and hetertrophioc nutrition e.g. euglena
what are consumers
they ingest organic molecules from living or recently killed organisms e.g. wolves and bear
waht are detritivores
(use internal digestion) they ingest organic molecules found in the non-living remanants of organisms e.g. leaf litter e.g. dung beetle, earth worms
what are decomposers
(extracellular digestion) release digestive enzymes and then absorb teh external products of digestion e.g. saphotrophs including bacteria and fungi
hwo does the fate of energy and nutrient differ in an ecosystem
energy flows through an ecosystem and it lost; a constant supply of energy is needed e..g from the sun. Nutrients are finite and are recycled within a closed ecosystem
–> illustrated by mesocosm ( an enclosed environment that allows a small part of the natural environment to be views under controlled conidtion
nutrients are recycled due to decomposers releasing enzymes to ecternally break down organic matter. This allows for inorganic compounds to be replenished e.g. returned to the soil
a ecosystem is sustainable if
- nutrient are availible
- detoxification of waste products
- energy is availible
