Energy Flow Flashcards
(20 cards)
what does feeding involve?
-the transfer of energy
what are producers?
-organisms which produce organic substrates from inorganic substances using energy
what do all producers use to make energy?
-light
what are consumers?
-organisms which obtain their energy by feeding on other organisms
-animals are consumers
what are the 3 types of consumers and what do they eat?
-primary consumers which eat plants, they are herbivores
-secondary consumers which eat primary consumers
-tertiary consumers which eat secondary consumers
-both are carnivores
what are the 2 groups of organisms involved in decay and decomposition? what is an example in an organism in each of these groups?
-decomposers- bacteria
-detritivores- earthworms
what is the purpose of a food chain, what does it show?
-the link of energy flow from a producer, primary consumer, secondary consumer and secondary consumer
what is each stage of the food chain known as?
-trophic level
why are food chains not an accurate representation of the transfer of energy between organisms?
-most organisms have more than one food source
what does the term quantitative relationships mean? how are these shown?
-information concerning the number and biomass of an organism at a specific trophic level
-this is not shown on food chains instead they are shown on ecological pyramids
what does the pyramid of numbers show?
-the total number of organisms at each trophic level
-the length of the bars show this
why do pyramids of numbers typically have a pyramid shape?
-due to proportionally there being more producers than any other trophic level
why are pyramids of numbers an inaccurate representation of energy flow? why can pyramids have an inverted shape sometimes?
-they do not take into account the size of the organism
-when very large numbers of a organisms in a trophic level are present, it is difficult to scale the bars properly
what do pyramids of biomass represent?
-the biomass of organisms which includes their fresh and dry mass
what is the difference in fresh and dry mass in terms of pyramids of biomass?
-fresh mass is more variable but still is somewhat accurate pyramid
-dry mass when organisms are heated and dried until a constant mass, is more accurate but time consuming
why are inverted pyramids of biomass less common than inverted pyramids of numbers?
-because with the biomass pyramids only the organisms present at any one time are assessed
why may the bar of the primary consumers be larger than the producers?
-due to a high reproductive rate
what is a pyramid of energy?
-it reflects the amount of new material which is produced
which of the pyramids is the most accurate but what is the disadvantage of this?
-pyramid of energy/ productivity
-more difficult and time consuming to obtain
what is the unit of pyramids of energy?
-kJm-2yr-1
-kilojoules per square meter per year
