Im teaching a erfly life cycle unit and I need help on my overview.?

I have to type an overview that provides a purpose for teaching the unit. I need to convince my audience that i believe what i am teaching is important to the education of the students. This is for second grade. For some reason the only thing that comes to my mind is bc it is a standard. Does anyone have any better ideas. I cannot say it's imp. bc its a state standard.