They do the same thing that all living and breathing things do! They breathe! When they breathe they are doing the same thing you are doing all day everyday. Inhaling oxygen and exhaling carbon dioxide.
Answer:d.are eventually replaced by electrons from photosytem 11
Explanation:there are two photosystems in the photosynthetic process.PSI and PS II. PS I has a reaction center called P700 because it's chlorophyll has a maximum absorption of 700nm wavelength.PSII has a reaction center called P680nm for similar reason.when an excited electron is transferred to P700,it becomes excited.this electron is passed down from from acceptor to another, until it is used to reduce NADP+ to NADPH.this electron is replaced when P680 gets excited by a photo of light and splits water to release electrons , protons and Oxygen
The brain stem is the answer that you are looking for
I think carbon dioxide then sugars