Topic 9- Ecosystems And Material Cycles Flashcards
definition of individual
A single organism
definition of population
All the organisms of one species in a habitat
definition of community
All the organisms of different species living in a habitat
definition of ecosystem
A community of organisms along with all the non-living (abiotic) conditions
definition of interdependent
When organisms depend on each other for things like food and shelter
explain what abiotic factors are
- Temperature
- Amount of water
- Light intensity
- levels of pollutants
explain what biotic factors are
- competition
* Predation
how to use quadrats
1) Place a 1 m² quedrat on the ground at a random the first sample area.
2) Count all the organisms you’re interested in within the quadrat.
3) Repeat steps 1 and 2 lots of times.
4) Work out the mean number of organisms per quadrat within the first sample area.
5) Repeat steps 1 to 4 in the second sample area.
6) Finally compare the two means. E.g. you might find a mean of 2 daisies per m² in one area, and 22 daisies per m² (lots more) in another area
pyramids of biomass
•shows how much the creatures would weigh if you put them together
- first level is the producer
- second level is the primary consumer and so on
equation for efficiency
Efficiency= energy transferred to next level/ energy available at previous level x 100
explain how humans affect biodiversity
- fertilisers can leach into water and cause eutrophication
- fish farming
- introduction of non-indigenous species
Conservation
Conservation methods:
•protecting a species natural habitat
•protecting species in safe areas outside natural habitat (eg.zoos)
•the use of seed banks
definition of reforestation
Reforestation is when land where a forest previously stood is replanted to form a new forest
name some benefits of maintaining biodiversity
- protecting the human food supply
- ensuring minimal damage to the food chains
- providing future medicines
- cultural aspect
- ecotourism
- providing new jobs
name some biological factors which affect the level of food security
- increasing consumption of meat and fish
- environmental changes caused by humans
- sustainability
- new pests and pathogens
explain the carbon cycle
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explain the water cycle
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explain the nitrogen cycle
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indicator species
Some organisms are very sensitive to change and so can be studied to see the effect of human activities
water pollution
Indicator species
-if raw sewage containing nitrates are released into a river the microorganisms increase and use up the oxygen
Some invertebrate are good indicators for water pollution as they’re very sensitive.
Eg. If you find Stonefly larvae in a river it indicates the water is clean
air pollution
Indicator species
Air pollution can be monitored by looking at particular types of lichen
As they’re sensitive to the concentration of sulphur dioxide
name the factors which affect the rate of decomposition
- temperature
- water content
- oxygen availability
definition of food preservation
•the process to slow decomposition
- storing food in the fridge or freezer
- storing food in air tight containers
- drying food (removes water)
what are the ideal conditions for decomposition?
Decomposition is fastest in warm, moist conditions with plenty of oxygen available
how to calculate the rate of decomposition
-find the gradient on a graph
