B17 Organising an ecosystem Flashcards
paper 2
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 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?
an organism that is killed and eaten by another organism
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
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
How can methane gas be used?
as a fuel
GIve the environmental changes that can affect the distribution of organisms.
temperature, availability of water and composition of atmospheric gases
