Unit 1 - Energy in food webs - (Week 5) Flashcards
Explain the difference between “autotrophs” and “heterotrophs”
Autotroph - An organism which can make its own food i.e. can photosynthesise (e.g plants)
Heterotroph - An organism which must
consume another organism to gain energy (e.g an animal)
State what “gross primary productivity” means
A measure of an autotroph’s energy uptake as the rate at which it produces biomass in a given area and time period.
State what “net primary productivity” means
NPP is GPP minus the energy used for respiration
State what “secondary
productivity” means
The production of new biomass in heterotrophs following consumption of plant’s NPP energy or
consumption of other heterotrophs Secondary Productivity
Explain what “ecological efficiency” is
the overall transfer
of energy from one trophic level to the next
State what “ectotherms” and “endotherms” are
Ectotherm - Rely on the external environment for temperature control e.g.reptiles (i.e sunbasking)
Endotherm - Use internally-generated heat to
maintain body temperature, regardless of external temperature e.g.mammals
Explain why food chains containing ectotherms tend to be longer than those containing
endotherms
Describe primary consumers in the tropic levles
Primary consumers are herbivores (plant eaters)
Describe secondary consumers in the tropic levles
Secondary consumers may be EITHER carnivores (meat eaters) OR omnivores (meat & plant eaters)
Describe what a scavenger is
eat carrion (dead
flesh)
Describe what a detritivore is
Detritivores – eat decaying vegetation
(plant litter, wood, debris, dung ) = the
equivalent of scavengers
Describe what a decompser is
Decomposers (bacteria, fungi, moulds) – the
plant equivalent of the scavenger.
Name 3 ways energy is lost
Movement, heat, passing of undigested waste
