Efficiency Of Ecosystems- Topic 10 Flashcards
Primary producer
Absorbs energy from the sun to synthesise organic molecules through photosynthesis
Primary consumer
Organisms that consume producers and use the organic molecules to supply raw materials for their own processes
Secondary consumer
Organisms that feed on primary consumers
Tertiary consumer
Feed on secondary consumers. They are usually the top predators
Decomposers
Final trophic level. Micro organisms that break down the remains of animals and plants returning mineral and nutrient to the soil
Why is there not likely to be quaternary consumers?
Not enough energy left to support them
What is the limitation of pyramid of numbers?
One producer could support multiple organisms
What is biomass?
Organic molecules built from sunlight energy
Limitations of a pyramid of biomass?
It’s more accurate to calculate dry mass but in order to do this you would have to oven an organism which is destructive to an ecosystem and ethically challenging.
Wet mass is usually measured and dry mass is estimated.
Different species may release different amounts of energy per unit mass
Why are organism who eat more than one type of species more successful?
Because changes in the food chain will have less impact on them
Name the 3 ways of representing trophic levels
Pyramid of number
Pyramid of biomass
Pyramid of energy
Why is such a low percentage of solar energy that reaches the leaf converted into biomass? 5 reasons
- Some light rays will not hit chloroplasts
- Used to heat earths atmosphere
- Used to evaporate water
- Reflected by clouds and earths surface
- Only some wavelengths of light can be used
Why isn’t efficiency of energy transferred to each trophic level 100%? (Producer to primary)
Producer will use some to respite and some will be lost as heat
Leaves fall
Why isn’t efficiency of energy transferred to each trophic level 100%? (Consumer)
Some of the plant is not eaten/ digested- eg cellulose
Lost in urine faeces heat and respiration
Next consumer will not digest whole organism (bones and hair)
What is gross primary product?
The total solar energy that plants convert to organic matter (relates to producers)
What is net primary production?
Amount of energy available to the next organism/ trophic level
How do you calculate NPP?
GPP- respiratory loss
Unit= gm-2 year-1 for biomass or kjm-2 year-1 for energy
What is trophic efficiency?
Efficiency of chemical potential energy transferred between trophic levels
How do you measure trophic efficiency?
Energy available after transfer divided by energy available before transfer times 100
Draw out the nitrogen cycle and the CO2 cycle
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The nitrogen cycle: haber process
Production of fertiliser combining nitrogen and hydrogen
The nitrogen cycle: nitrogen fixing
Atmospheric nitrogen into nitrogen containing compounds
The nitrogen cycle: ammonification
The conversion of nitrogen containing organic compounds to ammonia. Carried out by decomposers
The nitrogen cycle: denitrification
Conversion of soil nitrates into atmospheric nitrogen. By denitrifying bacteria
The nitrogen cycle: Which bacteria fixes ammonia?
Rhizobium
The nitrogen cycle: Which bacteria nitrifies ammonia into nitrites?
Nitrosomonas
The nitrogen cycle: which bacteria nitrifies nitrites into nitrates
Nitrobacter
Bombcalorimetry
- material burnt in oxygen
- temperature rise of water measured
- known volume of water
- chemical energy into heat energy
- convert temp into kJ
How is CO2 from the atmosphere moved into the ocean?
- dissolves in water
- for carbon fixation
- by photosynthesis of phytoplankton
What is the role of bacteria when adding CO2 back to the atmosphere?
- decomposition of organic matter
- bacteria produces enzymes for digestion
- respiration causes CO2 release
Suggest why more carbon is entering the air than is leaving it?
- rate of production of CO2 is greater than rate of removal
- fossil fuels release CO2 when burnt
- this CO2 was locked up years ago in carbon sinks
- deforestation = less photosynthesis
- as water temp increases less CO2 is dissolved in the water therefore higher atmospheric CO2
Why is there more CO2 at night?
No sunlight so photosynthesis stops
