your biology teacher is not incorrect. you'd have to be in a major-oriented botany course to completely grasp photosynthesis and cellular respiration.
here's a small summary: during the day while
photosynthesis is happening in the leaves of plants, carbon dioxide is expelled from the air and used to make sugars. At night, when
photosynthesis is not occuring and there is no sunlight for energy - respiration, as I stated earilier, is what occur and emits carbon dioxide.
what's important though, is that plants are requiews to take up much more carbon dioxide in photosynthesis
than they give off in respiration at night.
Plants generate carbon dioxide by combining glucose with oxygen in many intricate phases to make carbon dioxide and water.

-- danielle

How difficult is it to raise your hand and ask him your doubt!? It would be so rude to just go and complain about such a trivial thing. Most teachers like it when students have discussions and debates with them but please don't go behind their back and report them as incompetent!

your teacher is absolutely right . Do some research before you start your witch hunt. Here is some thing else you likely don't want to hear. It takes oxygen to rot plants down to compost. Lots of it

Oh my lord I hope people do not trust this as a source of information! Telling a confused student how to remove a teacher because of the students ignorance is just wrong!

Plants do indeed give off CO2, by breaking down glucose through an oxygen reacction. During the day they just happen to also emit large amounts of oxygen through photosynthesis in a completely different process. The teacher was absolutely right. The student and the The first poster alluded to the answer but not before giving advice on the removal of the teacher for reasons I cannot fathom!!!

I reecommend the student be removed and sent back to a remedial class, along with the other two people who answered a question they didn't know!

If your biology teacher tells you where babies come from
and you know the stork brings them, just smile knowingly to yourself.

I'd suggest talking to the Biology teacher about the matter. It's very possible that the Biology teacher can either prove it or correct the mistake. (We're all human, right?) But if that doesn't work and you still feel that the teacher is incompetent and would rather have a different teacher you could mention it to the principle/head of department/another biology teacher/counselor/dean. The list could go on and on.

By the way though-

Plants and Animals perform cellular respiration in order to use the energy in their body. Cellular respiration gives off some carbon dioxide even for plants. Plants exposed to light (performing photosynthesis) during the day time produce far more oxygen than they do carbon dioxide but at night the reverse could be true.

Just remember Photosynthesis and Cellular Respiration are two seperate processes and both vital to a plant.

Hope this helps.

In fact, oxygen
has been shown to prolong the lives of those who
need it

First, don't panic. Ask for clarity.

Second, be reasonable. If he/she doesn't remember, that's fine. Drop it and move on. It may have just been a slip of the tongue. If he/she corrects it or proves it, you're good! But if he/she has no idea whether it's true or not, feel free to panic.

Talk to your parents about talking to the principal or dean and ask for a department change. If the teacher really doesn't know anything, it's time to talk about removal.