Sydney drew a flow chart to illustrate the nitrogen cycle.
which labels best complete the flow chart?
x: producers undergo photosynthesis.
y: nitrogen compounds are released into the air.
x: nitrogen compounds are released into the air.
y: producers undergo photosynthesis.
x: free nitrogen is in the atmosphere.
y: producers absorb nitrogen compounds through their roots.
x: producers absorb nitrogen compounds through their roots.
y: free nitrogen is in the atmosphere.