B17: Organising an ecosystem Flashcards
what is a producer
organism that makes its own food, usually by photosynthesis
what is a food chain
representation of the feeding relationships within a community
what is a consumer
organism that only eats other organisms for food
what is a herbivore
organism that only eats producers (plants/algae)
what is a predator
organism that kills and eats other organisms
what is a prey organism
organism that is killed and eaten by other organisms
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 movements and to keep animals warm
what is the carbon cycle
process that returns carbon from organisms to the atmosphere as carbon dioxide, which can then be used by plants
what is the water cycle
process that provides fresh water for plants and animals on land before draining into seas and rivers
what is a decomposer
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
