Ecosystems/populations/sustainability Module 6 Flashcards
Habitat?
Place where an organism lives
Population?
All the organisms of one species in a habitat
Producer?
Organisms which produces organic molecules using sunlight energy
Decomposer?
An organism that breaks down dead or undigested organic materials
Trophic level?
A stage in a food chain occupied by a particular group of organisms
Ecosystem?
All the organisms living in a certain area, and all the non-living conditions found there
Dynamic system
Biotic factor?
Living features of an ecosystem
Abiotic factor?
Non living features of an ecosystem
How is energy transferred through an ecosystem?
Enters via photosynthesis
Plants store this as biomass
Energy passed on through organisms by eating each other
Why is not all energy passed on to the next trophic level?
Some of energy is never taken in, in the first place:
. Plants can’t use all light energy that reaches their leaves initially as some is wrong wavelength, reflected or passes through
Or light hits part of leaf which can’t photosynthesise
Some parts of organism aren’t eaten eg. bones or roots
Some parts are indigestible, forming faeces
Lost via respiration
Gross productivity?
The rest of the energy which is taken in (around 40%)
Net productivity?
The amount of energy available for the next trophic level
How do you find net productivity (biomass)?
gross productivity - respiratory loss
What do herbicides do?
Kill weeds that compete with agricultural crops for energy
What do fungicides do?
Kill fungal infections that kill crops
What do insectides do?
kills insect pests
What do fertilisers do?
chemicals that provide crops with minerals needed for growth eg. nitrates
How are intensive rearing livestock conditions controlled?
Animals kept in warm indoor pens, where movement is restricted, so less energy used moving around and keeping warm
Animals given food which is higher in energy than normal food
Describe the carbon cycle?
Carbon in form of CO2 in atmosphere is absorbed by plants when they carry out photosynthesis, becoming carbon compounds in plant tissues
Carbon passed on to animal consumers via feeding
All living organisms die and the Carbon compounds in the dead organisms are digested by micro organisms called decomposers, via saprobiontic feeding
Carbon returned to the air and water as all living organisms respire, including decomposers
However, if dead organic matter ends up in places where there aren’t any decomposers ( deep oceans or bogs), can be turned into fossil fuels ( heat and pressure over long time)
Carbon in fossil fuels released when they are burned = combustion
Other rocks formed from dead organic matter on sea floor, these rocks drawn down by tectonic plates, undergo chemical changes and release CO2, returned to atmosphere via volcanoes
Other rocks can also become land where they become chemically weathered and release CaCo3 ions into groundwater, which form the carbon containing rocks described above
Describe the Nitrogen cycle?
Nitrogen fixation
Ammonification
Nitrification
Denitrification
What’s Nitrogen fixation?
When Nitrogen gas in the atmosphere is turned into ammonia by bacteria such as Rhizobium and Azotobacter. The ammonia can then be used by plants
Also gets into system via lightening or fertilisers
Where’s Rhizobium found and it’s relationship?
Found inside root nodules of leguminous plants
Mutulastic relationship with the plants, as they provide plants with Nitrogen compounds, and they provide them with carbohydrates
Where do azobacter live?
Soil
What’s ammonification
When nitrogen compounds from dead organisms are turned into ammonia by decomposers, which go on to form ammonium ions
