A funny question , i came across..
July 25, 2009 5:06am CST
Our biology teacher told us that plants give off carbon dioxide (and he wasn't testing us). How can I report an incompetent teacher? :?
27 Jul 09
Years ago, they used to remove flowers from hospital wards at night because of the CO2... I believe that the photosynthesis process can only take place in daylight and thats when the plants take in CO2 and give out oxygen. (I may be wrong ... its been many years since my school biology lessons but that is my memory of them.)