4.7 Flashcards
Only approximately 10% of the biomass from each trophic level is transferred to the level above it.
List some reasons for these losses of biomass.
Not all the material is eaten e.g. bones are left behind.
Not all the ingested material is absorbed: some is egested as faeces.
Some absorbed material is lost as waste, such as carbon dioxide and water in respiration and water and urea in urine.
Energy is lost in respiration due to movement or for releasing heat to keep warm.
What are apex predators?
Apex predators are carnivores with no predators
How do decomposers digest and absorb nutrients?
Decomposers break down dead plant and animal matter by secreting enzymes into the environment. Small soluble food molecules then diffuse into the microorganism.
SECRETION –> DIGESTION –> ABSORPTION BY DIFFUSION
What are the roles of decomposers in recycling materials?
Decomposers return carbon to the atmosphere as carbon dioxide by respiration, and mineral ions to the soil.
What are abiotic factors? List some different abiotic factors.
Abiotic factors are non-living factors of an ecosystem.
Describe the Carbon cycle.
Combustion: Fossil fuels –> Atmosphere
Photosynthesis: Atmosphere –> Plant
Eating: Animals –> plants
Respiration: Animals / Plants / Decomposers –> Atmosphere
Fossilisation of dead plants and animals
Decomposition: Dead material –> Atmosphere
What abiotic factors affect the rate of decomposition?
Temperature - increase rate of action of the digestive enzymes
Water
Availability of oxygen - So the Decomposers can respire aerobically to release energy
What is the product of anaerobic decay?
Methane
Biogas generators can be used to produce ?? as a fuel.
Biogas generators can be used to produce methane gas as a fuel.
Which natural fertiliser can farmers add to crops?
Compost
The compost is used as a natural fertiliser for growing garden plants or crops
Describe the water cycle
Precipitation
Drainage (of water from soil into lakes/rivers/sea)
Evaporation
Photosynthesis
Respiration
