Water Cycle, Carbon Cycle,

& Nitrogen Cycle

7th Grade Life Science

Water CycleDescription: A model that describes how water moves from the Earth’s surface to the atmosphere and back again.

Carbon and Oxygen CyclesDescription: A model that describes how

carbon and oxygen molecules move between the living and non-living world.

Nitrogen Cycle Description:

A model that shows the transfer of nitrogen from the atmosphere to the soil to living organisms and back to the atmosphere.

Questions1. What are the three major processes that occur

during the water cycle?

EVAPORATION, CONDENSATION, PRECIPITATION

Questions2.What role do producers

play in the carbon and oxygen cycles?

THEY CONVERT CARBON DIOXIDE INTO OXYGEN

3.What role do consumers play in the carbon and oxygen cycles?

THEY CONVERT OXYGEN INTO CARBON DIOXIDE

Questions4.Why do organisms need nitrogen?NITROGEN IS A BUILDING

BLOCK OF MATTER THAT MAKES UP LIVING THINGS

5.What is nitrogen fixation and where does it usually occur?

NITROGEN FIXATION IS THE PROCESS OF CHANGING FREE NITROGEN IN TO A USABLE FORM OF NITROGEN. IT USUALLY OCCURS ON ROOT NODULES OF CERTAIN PLANTS.

THE BACTERIA THAT FIX NITROGEN GET SUGARS FROM THE PLANT AND THE PLANT IS SUPPLIED WITH NITROGEN.