Ecosystems And Material Cycles Flashcards
What is symbiosis?
The ecological relationship between two or more organisms living closely together with some sort of feeding relationship involved
What is mutualism?
Symbiosis when both organisms benefit
What is commensalism?
Symbiosis when one organism benefits and the other is not harmed
What is parasitism?
Symbiosis where one organism benefits and the other is harmed
What is an ecosystem?
A community of organisms and the physical environment they live in
What is a habitat?
A place where an organism lives
What is a population?
All the organisms of a particular species living in the same area
What is a community?
Populations of different species that live and interact with each other
What is interdependence?
When organisms in an area need each other for resources to survive
What are abiotic factors?
Non living factors that affect the distribution of organisms
What are biotic factors?
Living factors that affect the distribution of organisms
Name some abiotic factors that could affect the distribution of organisms
- Temperature
- Water availability
- Light avalibility
- Pollutants
Name some biotic factors that could affect the distribution of organisms
- Competition
- Predation
What is a belt transect?
A line created (eg. with a tape measure) where quadrants are placed along
What is a quadrat?
Frame placed on the ground where sampling can take place
What is a pyramid of biomass?
Pyramid where each level shows the relative biomass of each organism
How much biomass is typically transferred to the next trophic level?
10%
How do you calculate the efficiency of energy transfers between trophic levels?
Biomass transferred to the next level
—————————————————— x100
Biomass from the previous level
What calculation is used to estimate a population size based on data obtained from quadrats?
Number of organisms in all quadrats x total area where the organism lives
———————————————————————————————————
Total area of quadrats
Describe the role of bacteria in the nitrogen cycle
- Nitrogen fixing bacteria converts nitrogen into nitrates
- Decomposing bacteria breaks down waste products and dead organisms into ammonia
- Nitrifying bacteria converts ammonia into nitrates
- Denitrifying bacteria converts nitrates to nitrogen
What is eutrophication?
When lots of nutrients are added to water, resulting in too much plant growth eg. Due to adding too much fertiliser to crops
How does eutrophication cause a negative impact on biodiversity?
- Crops sprayed with too much water before heavy rain causes the fertiliser to run into nearby streams
- This causes algae and other plants to increase in number on the surface of the water
- This prevents sunlight from reaching plants at the bottom of the water
- These plants will begin to decompose as they won’t be able to photosynthesise
- The microorganisms decomposing the bacteria will respire, removing oxygen from the water
- This will cause other respiring organisms to die, reducing biodiversity
What impact can fish farming have on biodiversity?
Overfishing can lead to species becoming endangered
What impact can introducing a non-indigenous species have on an ecosystem?
They could prey on native species, reducing biodiversity
