Ecosystems Flashcards
what Is a community?
all the populations of different organisms that live together in the same habitat
what is an ecosystem?
a community and the habitat in which it lives
what is a habitat?
an area which an organism lives
what is a population?
all members of a single species that live in the same habitat
whats interspecific competition?
competition between two different species
what is intraspecific competition?
competition between the same species
what is biotic factors? name an example?
interactions between organisms that are LIVING
ie: bacteria can be included
list 5 abiotic factors?
light
temperature
water availability
oxygen availability
edaphic (soil) factors
salinity
what is abiotic factors?
non-living
list biotic factors
grazing
food availability
symbiosis (close and long term interaction between two different species)
disease
competition
why are ecosystems described as dynamic?
constantly changing environment and climate
Explain why abiotic factors may have a bigger effect on plant species than on animal species in an ecosystem.
Plants cannot relocate themselves to a different, more suitable habitat.
where does energy come from in the food chain? explain the process
- grass is a producer eaten by primary consumer
- energy enters the ecosystem by procurers
- the grass converts light energy from the sun into chemical energy during photosynthesis
how does energy enter an ecosystem?
through a producer
when energy enters a food chain through a producer via sunlight , what is this energy stored as in a plant?
biomass (organic material)
how does energy move from the producer to other members of the food chain?
energy transferred to the primary consumer when they eat the producer ie: grass
why isn’t 100% of the biomass transferred to the primary, secondary producer etc?
energy is also used for other body actions like respiration (growth and warmth) and excretion
in what form is energy always lost when being transferred during the food chain?
lost through heat
what is the equation for calculating efficiency?
efficiency = (biomass transfer / biomass intake) x 100
A blackberry bush with a mass of 35kg is fed upon by aphids with a collective mass of 4.1kg. Calculate the percentage efficiency of energy transfer in this step of the food chain.
Efficiency = (4.1 ÷ 35) x 100
Efficiency = 11.7%
how to calculate the net productivity of PRODUCERS?
NetPrimaryProductivity = gross primary productivity - respiratory losses
how to calculate productivity of CONSUMERS
net productivity = energy intake - (loss of excretion + respiratory losses)
what is nitrogen fixation?
when nitrogen gas in the atmosphere converts into ammonium by bacteria
what bacteria converts nitrogen gas into ammonium in nitrogen fixation?
rhizobium and azotobacter
Rhizobium is a bacteria involved in nitrogen fixation, where would this bacteria be found in plants and what do they do?
- found in the root nodules of legume plants
- provide pant with nitrogen compounds (used to make proteins)
what does the plant provide the bacteria rhizobium with? what biological molecule?
carbohydrates
what is ammonification?
when nitrogen compounds from dead organisms are converted into ammonium by decomposers
what happens during nitrification?
ammonium ions in the soil are converted into nitrates and nitrites used by the plant
during nitrification, bacteria is converted into another molecule, what happens?
1. what bacteria is used ?
2. what does the bacteria convert into?
- nitrosomonas bacteria -> convert ammonium into nitrites
- Nitrobacter bacteria -> converts nitrites into nitrates
what does the bacteria nitrosomonas do?
what part of the carbon cycle is this involved in?
converts ammonium into nitrites
involved in nitrification
what does nitrobacter convert into? what part of the nitrogen cycle is this used in?
converts nitrites into nitrates
part of nitrification
what is denitrification?
when nitrites and nitrates in soil converted into nitrogen gas by denitrifying bacteria
where does denitrification tend to happen?
in waterlogged soils
what happens during denitrification?
creates an anaerobic condition as gentrifying bacteria use nitrates in the soil for anaerobic respiration which produced nitrogen gas
what is a haber process?
when nitrogen from the air is reacted with hydrogen to form ammonia and this is used ti produce industrial fertilisers
in order what are the steps to nitrogen cycle
- nitrogen fixation
- ammonification
- nitrification
- denitrification
