Introduction explain: what is phylogenetics and why it is used and why it is important. Make sure to introduce why rbcL is important to plants, and life on earth in general. Why is it useful for DNA barcoding (what is DNA barcoding) and for making phylogenies of plants? Why are phylogenies useful? What kinds of questions can they be used to answer?
Discussion: statement of the purpose of study and hypothesis. Make sure to include some of the context from the introduction, remind us about our questions, then expand on the answers. Return to the broad biological context (Why do we care?)