Help with an experiment/question.

[Miascy93]

Hello Everyone!
I'm an 18 year old student doing his A2 levels and have found myself in a pickle. The examining board (edexcel) requires university standard work from us this year and that is fair does but unfortunately i haven't as yet been prepared for such a high standard of expertise so i hoped to find assistance in the bright young (and not so young) minds on the forums

My experiment is "How are stomatal numbers/sizes affected by growth conditions?" I have been advised to try direct observations of purple pigmented leaves as well as nail varnish peels. The experiment is simple enough the only thing i can't quite grasp is the research and rationale. How does this relate to people? (which it has to as one of the criteria for the coursework)
For example a friend of mine is doing the Effect of ph on catalase in red and white meat which obviously relates to us as we have catalase in our bodies and also we eat red and white meats so several different links to humans can be made but stomata? I'm sort of stuck

Any advice is welcome, i am definitely not asking for the work to be done for me. In fact ideally if you could post URL's to relevant articles i would much appreciate it especially since i have to cite sources

[JackBean]

The link is food production, biomass production and nowadays very popular CO2 binding