5.4 - Nutrient Cycles Flashcards
What is a decomposer?
Organism that breaks down dead or decaying organisms.
What is nitrifying bacteria?
Aerobic microorganisms found in the soil responsible for the oxidation of ammonium ions to nitrate ions.
What is denitrifying bacteria?
Anaerobic microorganisms found in waterlogged soils responsible for the reduction of nitrate ions to nitrogen gas.
What is nitrogen fixing bacteria?
Microorganisms responsible for the conversion of atmospheric nitrogen gas into nitrogen containing compounds.
What is a producer?
Photosynthetic organisms at the start of the food chain that manufacture biomass for all living things.
What is a consumer?
Organisms that feed on other organisms to obtain energy.
What is a herbivore?
Organism that feeds mostly on plants
What is a carnivore?
Animals that prey on and eat other animals. They can be secondary or tertiary consumers
What is a top carnivore?
Those organisms that have no natural predators
What is an omnivore?
An organism that eats plants and animals.
What is an autotroph?
Producer
What is a photoautotroph?
Organisms that carry out photosynthesis
What is a chemoautotroph?
Organisms that are able to synthesise their own organic molecules from the fixation of CO2
What is a heterotroph?
An organism that eats other plants or animals for energy and nutrients.
What is a food chain?
Describes the feeding relationships between organisms and the resultant stages of biomass transfer.
What is a food web?
The interconnection of many different food chains in a habitat
What are trophic levels?
The position of an organism in a food chain.
What is 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.
What is primary productivity?
The amount of sunlight/energy
What is gross primary productivity?
The total amount of chemical energy stored in plant biomass in a set area or volume.
What is 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
What is a climax community?
An ecological community in which populations of plants or animals remain stable and exist in balance with each other and their environment.
What is nitrogen fixation?
The conversion of atmospheric nitrogen gas into nitrogen-containing compounds by nitrogen fixing bartend in the sailor root of nodules legumes.
What is ammonification?
The production of ammonia when saprobiontic micro organisms feed on organic nitrogen-containing compounds. Ammonium ions are formed and added to the soil.