In humans, yes...
At night, when plants “breathe” in CO2, they expel CO2...
At day, when plants “breathe” in CO2, due to photosynthesis, they expel O2 (oxygen)
So, at night, plants put out the same amount of CO2 that they take in....
“At night, when plants “breathe” in CO2, they expel CO2...”
you get an ‘F’.