Trophic Levels Flashcards
What is a heterotroph
Must consume other organisms to obtain energy
What is a primary consumer
Herbivores, heterotrophs that eat plant material
What are secondary consumers
Carnivores that feed on primary consumers
What are tertiary consumers
Carnivores that eat other consumers
What is a trophic level
The position a species occupies in a food chain
What are detritivores
Primary consumers that feed on dead organic material
What are decomposers
Bacteria and fungi that feed on the dead remains of organisms and animal faeces, are heterotrophs
How do decomposers feed on dead remains
Secrete enzymes and digest their food externally before absorbing it
Ways plants do not absorb all energy
-the chlorophyll can only absorb certain wavelengths
-some energy lost during photosynthesis and transferred to the environ
-limiting factors also influence rate of photosynthesis eg temp and CO2 concen, means not all absorbed energy can be used to make organic molecules
What is gross primary productivity(GPP) and it’s units
The amount of chemical energy stored in the carbohydrates within plants during photosynthesis, usually energy per unit area per year
What is net primary productivity (NPP)
The amount of chemical energy available for transfer to herbivores after plant respiratory losses
What is percentage efficiency of photosynthesis
GPP / amount of light arriving at the plant surface X 100
How to calculate NPP
Net primary productivity = gross primary productivity - plant respiratory losses
Reasons for loss in biomass between trophic levels
-not all available food gets eaten (some parts of plant are protected by spines or thorns, bones)
-some indigested food remains in faeces (eg cellulose in plants)
-used in respiration (used for movement and chemical reactions, maintaining constant body temp)
When is there less energy lost, in food chain with more or less species
With more as food chain can support more organisms
