1. EAR - biophysical interactions which lead to diverse ecosystems and their functioning

Question 1

Difference between community and ecosystem

Answer 1

Community only biotic organisms and their interactions

Ecosystem is the interactions between abiotic and biotic

Question 2

How are all the biophysical interactions linked? Flow chart

Include examples

Answer 2

Energy is transferred from organisms through food chains/webs –> higher up trophic level, more energy is lost as only 10% is passed from one level to the next

Food chains facilitate nutrient cycling which are required for organisms to survive –> from abiotic to biotic components –> operates in stores/spheres - atmosphere/hydrosphere/lithosphere/atmosphere
EXAMPLES INCLUDE carbon, nitrogen, phosphorus cycles

Question 3

Carbon cycle importance and (atmosphere)

Answer 3

essential chemical for plant/animal nutrients - all organisms primarily composed of carbon

Atmosphere - CO2 and methane

Question 4

Carbon cycle (terrestrial biosphere)

Answer 4

Plants absorb carbon for photosynthesis, animals release CO2 during cellular respiration, release methane during digestion, soil decomposers release carbon into atmosphere and soil

Question 5

Carbon cycle (lithosphere)

Answer 5

Fossil fuels like coal, oil, natural gas & limestone

Volcanoes may release some of this stored carbon

Question 6

Carbon cycle (hydrosphere)

Answer 6

Absorbs and stores large amounts of carbon, plankton absorb carbon dioxide for photosynthesis

Question 7

Carbon cycle (anthropogenic activity) - 3

Answer 7

• Humans burn fossil fuels which releases carbon into atmosphere via combustion - fossil fuel mining releases carbon that has been stored for thousands of years in lithosphere –> carbon cycle increased in productivity
• Production of clinker used for cement from limestone = releases carbon
• Deforestation increases amount of carbon in atmosphere

Question 8

Outline nitrogen cycle 4 steps (and a brief statement on importance)

Answer 8

All organisms require nitrogen to make amino acids which are used to build proteins

(1) Atmospheric nitrogen falls to earth through precipitation (rain or snow)
(2) Bacteria in soil allows it to become absorbed by plants, which animals consume and reuse the nitrogen to make their own proteins
(3) When organisms die, the decomposed faeces/animal allows nitrogen to be absorbed into the soil as ammonia.
(4) Other soil bacteria convert nitrates into nitrogen gas (denitrification) > releases nitrogen into the atmosphere once again

Question 9

Phosphorus cycle (5 steps)

Answer 9

(1) Phosphorus is eroded by wind and rain.
(2) Producers absorb the phosphorus through their roots.
(3) Herbivores then eat the plants, absorbing the phosphate, then the consumers when they eat the herbivores.
(4) Finally, phosphorus is deposited back into the soil when plants and animals decay or through animal waste.
(5) Some phosphorus may leach into water, where the formation of phosphate sediments creates an underwater phosphate reserve, which will very slowly cause geological uplift and formation of new rock.