23) Ecosystems Flashcards
What is a producer
Organism that produces organic molecules using sunlight energy
What is a consumer
Organism that eats other organisms
What is a decomposer
Organism that breaks down dead or undifested organic material
What is the trophic level
A stage in a food chain occupied by a particular group of organisms
What is a dynamic system
Where factors are changing all the time
What are biotic factors?
Give examples
Living features of an ecosystem
eg. predators , microorganisms
What are Abiotic factors?
give eg.
Non-living features
eg. temp , rainfall , soil nutrient availability
What is the main route by energy enters an ecosystem
Photosynthesis
How is energy transfered in the ecosystem
Photosynthesis convert sunlight energy used by producers.
They store energy as biomass.
Energy transfered by biomass transfers.
Energy is transfered when amother organism eats other organisms.
What is thhe difference between Food Chain and Food Web
Food Chain - Shows energy transfer
Food Web - How food chains can overlap.
What happens with energy that can’t be eaten
Gets recycled back into the ecosystem by decomposers
How much percentage of energy is never taken in by organisms
60%
How can energy not entirely be taken in by oganisms.
give eg.
Some wrong wavelenth of light is reflected
Some light passes through the leaves
Not all light is taken up for photosynthesis
Some parts are not entirely eaten by organisms ( roots or bones)
Some food are indigestible to come out as waste
What is the energy taken in called
gross productivity
what happens to 30% of the totel energy
lost to the environment by respiration
what happens to 10 % of the gross productivity
becomes biomass
How do you find net productivity
gross productivity - respiration loss
How do you find the energy efficiency of an organism
energy transferred / energy intake x 100
How can energy transfer be measured
Calculate the difference between amount of energy in each level.
Measure the dry mass (biomass)
What is primary succession
processes of creating life in an area where no life previously existed
What is secondary succession
restabilizationrhat follows a disturbance where life has formed an ecosystems
What is primary succession
Where species colonise a barren place ( without soil )
progress to climax stage
What are pioneer species
give eeg.
The first species to colonise an area.
Lichens , moss
What effect does pioneer species change to abiotic conditions
Die and microorganisms decompose into organic matter.
Make soil and nutrients.
Reduce abiotic conditions.
Stabilise environment
reduce soil pH
availability of water
What happens to the ecosystem when abiotic conditions become less hostile
Attract more animals and insects
Larger plants such as shrubs start to grow .
Create habitats.
Why does biomass increase in secondary sucession
Different plants and animals are more adapted , larger and more dense plants out compete smaller plants .
What is Climax community
Final stage of succession.
Stable group of largest and most complex plants.
What are threats to climax community
forest fire
deforestation
human building
agriculture purpose
What is deflected succession
community remain stable , human activity prevents succession from happening
What is plagioclimax
When succession is stopped aertifically
Give examples of plagioclimax / deflected succession
agricultre
animal grazing
burning an area
remove vegetation
What is the carbon cycle
Hoe carbon moves through living organism and non-living environment.
What processes are does the carbon cycle include
photosynthesis
respiration
decomposition
combusion
weathering
Describe how carbon is absorbed by plants in photosynthesis
Carbon is passed on to primary consumers when they eat plants , passed onto secondary and tertiary consumers when they eat other consumers.
What happens to carbon in decomposition ?
What is this also known as .
Saprobionic nutrition.
Living organisms die and carbon compounds deigested by microorganisms by decomposers. Feed of dead organic matter
Carbon recycle in respiration
carbon and water returned to aire from all organisms , produce oxygen
How are fossil fuels formed
Dead organic matter end up places where there are no decomposers .Carbon compound turns into ff over million years.
How is carbon released in fossil fuels
when burnt , combustion
- other types of rock can be formed from dead organic matter deposited on the sea floor
lime + chalk composed of calcium carbonate.
Carbon turned into rocks such as Limestone
What does chemical weathering causes
Mineral ions and bicarbonate ions released from rock into solution and enter ground water , transported into river and oceans. Form carbon containing compounds
How is carbon reabsorbed from oceans
co2 dissolve directly into oceans and transported by deep underwater currents. released back into atmosphere
Why do plants and animals need nitrogen
Make proteins and nucleic acids
what is the nitrogen cycle
How nitrogen is converted into a useable form and passed between living and non-living environment
Why is bacteria needed in the nitrogen cycle
cinvert atmosphere nitrogen into nitrogen compounds to be used
What is the 4 different processes in the nitrogen cycles that involve bacteria
nitrogen fixation
ammonification
nitrification
detrification
How does the nitrogen fixation recycle nitrogen
gas into ammonia by bacteria.
Ammonia used by plants.
Form mutualistic relationships - privide plant with nitrogen compounds and provide carbohydrates
How does ammonification recycle nitrogen
Nitrogen compounds from dead organisms turn into ammonia by decomposers
Form into ammonium ions
Urine and faeces turn into ammonia by decomposers
How does nitrification recycle nitrogen
ammonium ions in soil into nitrogen compounds used by plants
Nitrifying bacrer change ammonium ions into nitrites.
Nitrobacter change nitrites into nitrate
How does denitrification recycle nitrogen
nitrates in soil conver into nitrogen gas by denitrifying bacteria.
carry out respiration and n gas.
Under anaerobic conditions
what are the other ways nitrogen is returned into ecosystem
lightning (atmospheric nitrogen )
Artificial fertilisers
