To investigate whether an organism in the study is capable of both photosynthesis and respiration, a comparison of which treatment groups is most appropriate

Yes.

Explanation:

Yes, plant is the organism that is capable of both photosynthesis and respiration at the same time because prepare food as well as generate energy from respiration process at the same time. Plants make their own food through the process of photosynthesis by using water and Carbondioxide gas while on the other hand, energy produces in the process of respiration by using of glucose and oxygen.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.