Defenitions Flashcards
Food chain
Showing the transfer of energy from one organism to the next, beginning with a producer
Food web
A network of interconnected food chains
Producers
An organism that makes its own organic nutrients, usually using energy from sunlight, through photosynthesis
Consumers
An organism that gets its energy by feeding on other organisms. They may be classed as primary, secondary, tertiary and quaternary according to their position in a food chain
Primary consumer
First consumer in a food chain, they eat producers
Secondary consumer
Second consumer in a food chain, they eat the primary consumer
Tertiary consumer
Third consumer in a food chain, they eat the secondary consumer
Quarternary consumer
Fourth consumer in a food chain, they eat the tertiary consumer
Herbivore
An animal that gets its energy by eating plants
Carnivore
An animal that gets its energy by eating other animals
Decomposer
An organism that gets its energy from dead or waste organic material
Trophic level
The position of an organism in a food chain, food web or ecological pyramid.
Arrows in a food web
Arrows represent the energy being transferred
Ecosystem
A unit containing the community of organisms and their environment, interacting together
Energy loss in food chains
How does this occur?
Through movement, respiration, excretion and not eating the whole organisms
Respiration
Is a chemical process that involves the breakdown of nutrient molecules (specifically glucose) in order to release the energy.
oxygen + glucose → carbon dioxide + water
Photosynthesis
Is a chemical reaction that requires energy, water and carbon dioxide to synthesise glucose. Oxygen is a by-product
Decomposition
When living organisms die, cells are broken down. The decomposers use the material they gain to respire
Combustion
The burning of fuels (like fossil fuels) to realise energy. Carbon dioxide is released too
Fossilisation
Forming of fossils
Describe the Carbon Cycle
Look on internet for diagram
Describe the Nitrogen Cycle
Look on internet for diagram
Nitrogen fixation
Convert nitrogen gas into nitrates. Examples; nitrogen fixing bacteria, lightning, fertiliser (haber process)
Denitrification
Converting nitrates into nitrogen gas. Done by denitrifying bacteria
Nitrification
Converting ammonium ions into nitrite and then nitrate
Decomposition
Breakdown of plants and animal by microorganisms, forming ammonium ions
Deamination
Happens in animal. Converting amino acids into urea.
Lag phase
Organisms are adapting to the environment before they are able to reproduce; in addition, at this stage there are very few organisms and so reproduction is not producing larger numbers of offspring
Log phase/exponential phase
Food supply is abundant, birth rate is rapid and death rate is low; growth is exponential and only limited by the number of new individuals that can be produced
Stationary phase
Population levels out due to a factor in the environment, such as a nutrient, becoming limited as it is not being replenished; birth rate and death rate are equal and will remain so until either the nutrient is replenished or becomes severely limited
Death phase
Population decreases as death rate is now greater than birth rate; this is usually because food supply is short or metabolic wastes produced by the population have built up to toxic levels
