B18 - Trophic levels Flashcards
trophic levels
-positions within food chains of organisms
Trophic level 1
-producers
-largest level
producers
make their own food by photosynthesis
Trophic level 2
-primary consumers
-herbivores eat plants
Trophic level 3
-secondary consumers
-carnivores eat herbivores
Trophic level 4
-tertiary consumers
-carnivores that eat other carnivores
apex predator
-found at top
-nothing eats them
biomass
mass of material in living organism
measuring biomass
-dry mass in grams
con of dry mass
-must be dead to dry and measure
wet mass
-isnt killed
-less repeatable as water content varies
changes of biomass through each Trophic level
decreases
reason for changes of biomass through each trophic level
-not all matter is consumed = eg bones/roots
-lost in waste of organism (urea)
-lost in respiration
how do decomposers break down dead matter
-secrete enzymes
-small soluble molecules diffuse into micro organism
incident energy
-light from sun arriving at Earth’s surface