The nitrogen cycle. Which labels best complete the flow chart?
O X: Producers undergo photosynthesis.
Y: Nitrogen compounds are released into the air.
O X: Nitrogen compounds are released into the air.
Y: Producers undergo photosynthesis.
O X: Free nitrogen is in the atmosphere.
Y: Producers absorb nitrogen compounds through
their roots.
O X: Producers absorb nitrogen compounds through
their roots.
Y: Free nitrogen is in the atmosphere.
TS
T
S.