4.10: Describe the Stages in the Nitrogen Cycle, Including the Roles of Nitrogen Fixing Bacteria, Decomposers, Nitrifying Bacteria and Denitrifying Bacteria (Specific Names of Bacteria are Not Required)

NITROGEN CYCLE: Describes the Movement of Nitrogen Compounds in the Environment

THE NITROGEN CYCLE

Diagram Showing the Nitrogen Cycle

EXPLANATION: NITROGEN FIXATION Nitrogen Gas in the Atmosphere is Too Unreactive to be Used Directly so Needs to be Converted into Soluble Ions Nitrogen Fixing Bacteria in Root Nodules of Legumes will Convert Nitrogen Gas into Nitrates for Use Lightning will Convert Nitrogen Gas into Nitrates Haber Process will Convert Nitrogen Gas into Ammonia, in which Nitrifying Bacteria will Convert into Nitrites, then Nitrates ABSORPTION BY PLANTS Plants will Absorb Nitrates through the Roots by Active Transport Nitrate Ions Help Produce Amino Acids which will become Protein, Becoming Part of Plants Biomass MOVING ALONG FOOD CHAINS Animals will Eat Plants and Nitrogen from the Plant’s Protein will become Protein in the Animal Nitrogen is also Passed from One Animal to Another by Feeding DEATH OF ORGANISMS Decomposers (Bacteria and Fungi) will Break Down urea, Egested Material and Dead Bodies and Nitrogen Compounds will be Returned to the Soil as Ammonium Ions Nitrifying Bacteria will Convert Ammonium Ions into Nitrites, then Nitrates for Plants to Absorb DENITRIFICATION Denitrifying Bacteria in the Soil will Break Down Nitrates and Return Nitrogen Gas into the Air This Occurs in Waterlogged Soil so can be Prevented by Reducing Drainage

4.9: Describe the Stages in the Carbon Cycle, including Respiration, Photosynthesis, Decomposition and Combustion

CARBON CYCLE: Describes the Movement of Carbon Molecules in the Environment

THE CARBON CYCLE

Diagram Showing the Carbon Cycle

EXPLANATION: RESPIRATION All Living Organisms will Respire Aerobically and Release Carbon Dioxide into the Atmosphere as Organic Compounds that are Broken Down to Release Energy PHOTOSYNTHESIS Photosynthesis Fixes Carbon Atoms from Atmospheric Carbon Dioxide into Organic Molecules and Becomes Part of Complex Carbon Compounds in Plants DECOMPOSITION Dead Organisms are Broken Down by Decomposers and Carbon in their Bodies are Returned to the Atmosphere as Carbon Dioxide COMBUSTION If Decomposition is Blocked, Plant and Animal Material are Available as Fossil Fuels After a Long Period of Time Combustion of Fossil Fuels Releases Carbon Dioxide Back into the Atmosphere

4.8: Describe the Stages in the Water Cycle, including Evaporation, Transpiration, Condensation and Precipitation

WATER CYCLE: Describes How Water Moves on, Above and Below the Earth’s Surface

THE WATER CYCLE

Diagram Showing the Water Cycle

EXPLANATION: EVAPORATION The Sun will Emit Energy that will Heat the Earth’s Surfaces and cause Water Vapours to Evaporate from Oceans, Rivers and Lakes TRANSPIRATION Transpiration from PLants Releases Water Vapour into the Air and will Evaporate CONDENSATION As Moist Air Rises and Cools Down, Water Vapours will Condense to Form Liquid Water that will Produce Clouds PRECIPITATION As Water Droplets in Clouds become Bigger and Heavier, they will Fall as Rain, Snow and Sleet