10.2- efficiency of ecosystems

Question 1

energy loss in trophic levels

Answer 1

-energy is lost as each trophic loevel
-mot all is transerred to enct level

Question 2

what is a producer

Answer 2

-make food
-plants and algae trap light from sun and use it in photosynthsis to make ATP

Question 3

what is a primary consumer

Answer 3

-organisms that eat producers, herbivores

Question 4

secondary consumers

Answer 4

-animals that feed on herbivores, carnivores

Question 5

tertiary consumers

Answer 5

-animals that feed on carnivores, usually top predators unless quaternary

Question 6

what is an ecosystem?

Answer 6

-An ecosystem is a life-supporting environment. It includes all of the organisms living in a particular area known as a community, as well as all of the non-living elements of that particular environment.
-All organisms in an ecosystem interact with one another in complex ways. These are sometimes represented in food webs.

Question 7

how is energy lost between trophic levels?

Answer 7

-some parts are the food are not or cannot be eaten e.g. bones
-some foods cannot be digested e.g. certain plant fibres
-energy lost to environment as heat or waste

Question 8

3 types of ecological pyramids

Answer 8

-pyramid of number
-pyramid of biomass
-pyramid of energy

Question 9

pyramid of number

Answer 9

-compare number of organisms at each trophic level
-producers at bottom to tertiary at top
-not great as e.g. small population of ladybirds eat a larger population of aphids

Question 10

pyramid of biomass

Answer 10

-compare mass of biological material at each tropic level
-wet biomass very inaccurate as it is affected by water uptake in the soil
-dry involves destroying material, so a small sample is used and total biomass is calculated from it
-much more time consuming but more accurate

Question 11

pyramid of energy

Answer 11

-amount of energy passing through each trophic level over a period of time -most accurate model of what is happening in an ecosystem
-energy remains same at every level but the size of different types of energy stores changes
-as you move along food chain, less energy in organisms and more in surrounding environment

Question 12

how to calculate energy efficiency

Answer 12

energy transferred to biomass/ total energy supplied to organism

Question 13

what is gross primary productivity

Answer 13

-rate at which plants capture sunlight to produce new plant material

Question 14

net primary productivity

Answer 14

-energy transferred into biomass, available to next trophic level

Question 15

net primary productivity calculation

Answer 15

NPP= GPP-respiration

Question 16

energy transfer calculation

Answer 16

NPP/GPP multiplied by 100

Question 17

what impacts NPP

Answer 17

-water within an ecosystem
-latitude (light available)
-plant density

Question 18

nutrient cycling

Answer 18

-Energy flow through living organisms is unidirectional and is eventually lost to the environment as wasted heat.
-Matter, however, is continually recycled between living and non-living things.

Question 19

what does the carbon cycle consist of?

Answer 19

-released during respiration of plants, animals and decomposers
-in decaying matter and waste
-stored in fossil fuels such as coal and oil
-released into atmosphere when fossil fuels are burned (combustion)
-used in photosynthesis to produce carbs

Question 20

what is the nitrogen cycle

Answer 20

-recycling of nitrogen between biotic and abiotic phases of an ecosystem

Question 21

parts of the nitrogen cycle

Answer 21

-decomposers act specifically on proteins, breaking them down to form ammonium compounds
-these ammonium compounds are then oxidised by nitrifying bacteria that convert them to nitrates
-these are returned back to soil and absorbed by plants
-nitrogen fixing bacteria in soil can convert nitrogen from soil into ammonia, which is then converted to nitrates by nitrifying bacteria
-legumes are particularly important (beans and peas) have nodules on their roots that are full of nitrogen fixing bacteria, an example of mutualism
-denitrifying are not helpful as they use nitrates as energy source and break them down again into nitrogen gas, reducing nitrates in soil

Question 22

what is a carbon sink

Answer 22

-resivoir where carbon is removed from the atmosphere and ‘locked up’ in organic or inorganic compounds