Cycles in ecosystems Flashcards
What is a producer?
Organisms that make their own food, usually by photosynthesis
What is a food chain?
Representation of the the feeding relationships within a community
What is a consumer?
An organism that eats other organisms for food
What is an apex predator?
Carnivore with no predators
What proportion of biomass is transferred from each trophic level to the one above?
Approximately 10%
Why is biomass lost between trophic levels?
Some ingested material is egested, some material is lost as waste (carbon dioxide and water in respiration, water and urea in urine), used in life processes, such as respiration, energy is used in movement and to keep animals warm
Which process removed carbon from the atmosphere?
Photosynthesis
Which processes add carbon dioxide to the atmosphere?
Respiration and combustion
What is a decomposer?
An organism that breaks down dead plant and animal matter
What is the role of decomposition?
Returns carbon to the atmosphere and mineral ions to the soil from dead matter
What factors affect the rate of decay by decomposers?
Oxygen levels, moisture levels, temperature and pH
What gas does anaerobic decay produce?
Methane gas and carbon dioxide
Give the environmental changes that can affect the distribution of organisms?
Temperature, availability of water and composition of atmospheric gases
Define “Biomass”
Dry (without water) mass of biological material in an organism
What is a predator - prey cycle?
The interdependent cycles of population increase and decrease of predator and prey populations
How does carbon from plants and animals get formed into rocks?
Fossilisation
Name the process where water is rained down from the clouds
Precipitation
Name the processes where where water escapes from the oceans and into the clouds
Evaporation and condensation
