7.2 Organistion of an Ecosystem Flashcards
define population
a species that occupy the same habitat.
define habitat
the place in which an organism lives.
define community
populations of different species interacting.
define ecosystem
the interactions between the biotic and abiotic factors in an area.
what do food chains show?
food chains show the feeding relationships of different organisms and the flow of energy between the organisms.
define biomass
the total mass of living material.
what are trophic levels?
the stages in a food chain.
what do arrows in a food chain represent?
the direction of biomass transfer.
describe a simple food chain
producer –> primary consumer –> secondary consumer –> tertiary consumer.
what is a producer?
an organism that makes it own food.
what types of organisms are primary producers?
photosynthetic organisms like green plants and algae that trap energy from the sun.
what is a primary consumer?
an organism that feeds on producers.
what is a secndary consumer?
an organism that feeds on primary consumers.
what is a predator?
a consumer that kills and eats other animals.
describe how materials cycle through the living and non-living components of an ecosystem
- organisms take in elements from their surroundings e.g. soil, air
- elements converted to complex molecules which become biomass.
- elements transferred along food chains.
- elements returned to environment during excretion and decomposition of dead organisms.
what is a tertiary consumer?
an organism that feeds on secondary consumers.
what is prey?
an animal that is killed and eaten by another animal.
describe the pattern of predators and prey in a stable community
the numbers of predators and prey rise and fall in cycles.
why are producers the first trophic level?
- producers provide all biomass for the food chain )production of glucose via photosynthesis).
- the rest of the food chain involves the transfer of this biomass.
what piece of apparatus is used to measure the abundance and distribution of organisms in an area?
quadrat
what piece of apparatus is used to study the distribution of organisms across a gradient?
belt transect
when considering the abundance of organisms, what is meant by the term “mean”?
the average number of organisms.