Topic 5 - Nutrient Cycles Flashcards
Define decomposer
Organism that breaks down dead or decaying organisms.
Define nitrifying bacteria
Aerobic microorganisms found in the soil responsible for the oxidation of ammonium ions to nitrate ions.
Define denitrifying bacteria
Anaerobic microorganisms found in waterlogged soils responsible for the reduction of nitrate ions to nitrogen gas.
Define nitrogen fixing bacteria
Microorganisms responsible for the conversion of atmospheric nitrogen gas into nitrogen containing compounds.
Define producer
Photosynthetic organisms at the start of the food chain that manufacture biomass for all living things.
Define consumer
Organisms that feed on other organisms to obtain energy.
Define herbivore
Organism that feeds mostly on plants
Define carnivore
Animals that prey on and eat other animals. They can be secondary or tertiary consumers
Define top carnivore
Those organisms that have no natural predators
Define omnivore
An organism that eats plants and animals.
Define autotroph
Producer
Define photoautotroph
Organisms that carry out photosynthesis
Define chemoautotroph
Organisms that are able to synthesise their own organic molecules from the fixation of CO2
Define heterotroph
An organism that eats other plants or animals for energy and nutrients.
Define food chain
Describes the feeding relationships between organisms and the resultant stages of biomass transfer.
Define food web
The interconnection of many different food chains in a habitat
Define trophic levels
The position of an organism in a food chain.
Define biomass
The total mass of organic material, measured in a specific area over a set time period. This can be calculated in terms of dry mass or mass of carbon per given area.
Define primary productivity
The amount of sunlight/energy
Define gross primary productivity
The total amount of chemical energy stored in plant biomass in a set area or volume.
Define net primary productivity
The chemical energy store that remains when energy losses due to respiration are subtracted from the total energy store. This is used in plant growth or reproduction and is also available to other trophic levels.
NPP = GPP-R
Define climax community
An ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.
Define nitrogen fixation
The conversion of atmospheric nitrogen gas into nitrogen-containing compounds by nitrogen fixing bartend in the sailor root of nodules legumes.
Define ammonification
The production of ammonia when saprobiontic micro organisms feed on organic nitrogen-containing compounds. Ammonium ions are formed and added to the soil.
What are the four main steps of the nitrogen cycle?
- Ammonification
- Nitrification
- Nitrogen fixation
- Denitrification
Explain the process of nitrification
The process by which reduced nitrogen compounds (primarily ammonia) are oxidised into nitrite and nitrate.
Explain the process of denitrification
When nitrates in soil are converted into nitrogen gas by denitrifying bacteria - they use nitrates in the soil to carry out respiration and produce nitrogen gas.
What is the function of nitrifying bacteria?
Nitrifying bacteria gain energy from oxidising ammonium ions, free living bacteria in soil.
Explain the process of ammonification
When nitrogen compounds from dead organisms are turned into ammonia by saprobiants which goes onto form ammonium ions.
Explain the process of nitrogen fixation
When nitrogen gas in the atmosphere is turned into nitrogen containing compounds.
What are the equations for nitrification?
NH4+ -> NO2-
NO2- -> NO3-
What are the four stores in the phosphorus cycle?
- Phosphate ions in animals
- Phosphates in rocks
- Phosphate ions in waste and remains
- Dissolved phosphate ions in oceans, lakes and soils.
What are the living components in the phosphorus cycle?
Animals
What are the non-living components in the phosphorus cycle?
Rocks, oceans, lakes, soils, shells and waste and remains
What are producers and consumers?
Producers - plants and algae that photosynthesise
Consumers - animals get energy from eating other organisms.
What are primary and secondary consumers?
Primary - animals that eat plants
Secondary - animals that eat primary consumers
What are decomposers?
Organisms that break down and obtain energy from dead organic matter.
What are some factors causing low rate of energy exchange?
Not all of organisms night be consumed
What is consumed may not be digestible and lost in faeces.
What is energy lost as in respiration?
Excretion and heat
What is the equation for efficiency of energy transfer?
Energy available after transfer/ 100 x energy available before transfer
What can ecological pyramids show?
Quantitive measurements of food webs and chains - can show the number of a species, the biomass or the amount of energy stored at each trophic level.
What is energy in pyramids of energy measured in?
Kilojoules per square metre per year.
What is phosphorus a component of?
DNA, ATP and phospholipids
What are mycorrhizae?
Means fungus root.
Exemplifies a symbiotic relationship between fungus and a plant.
How is mycorrhizae a mutualistic relationship?
The fungus absorbs and passes ins and mineral water to the plant. The plant passes organic compound such as glucose to the fungus.
Explain the process of eutrophication
NAME?
What is soil leaching?
NAME?
What are fertilisers used for?
Used to add important mineral ions, back into the soil.
What are natural fertilisers?
Made up of organic matter in the form of the dead and decomposing remains of organisms and their waste products
What are artificial fertilisers?
Made up of inorganic matter in the form of powders or pellets that contain pure chemical compounds.
