Need help with my biology essay on plant hormones?

Question

i need to design an experiment on the "role of hormones in phototropism"... 1. i need to write an explanation of the variable to be tested and how this variable plays a role in the regulation of said effect... well basically what im going to do is explain what darwin and dawin found out that auxin is located at the tip of a plant and also boysen-jensen ... and then ganna poretend im Went doing his experiment... to find out that auxin gets centered in one side of the plant.. (dark side) and elongates there... what i want to know is whar is the variable to be tested? like the plant or the hormone? and also i want to know if my topic is a short "role of hormones in phototropism" should i do two experiments where one is where i find out that auxin is located on the tip of a plant and one where i test the plants with no tip but with a control and couple with agar blocks with auxin in them or should i just do one and give the dawin and dawin theory as a background...thanks alot

Answer 1

try some of these websites. They will give you some ideas as to what variable (which I think is to do with the tip ie. ifi ts covered, cut, separated by gel etc...but don't quote me on this!) and what to do in an experiement.
You technically dont' need to do "two experiements" as its all part of the same thing. You are trying to determine where the auxin is located and how it affects plant growth in the tip. Doing all the different things to the tip will answer it all.
You need to have a control of course and refer back to what Darwin did to maybe explain and compare what is happening in scientific terms (ie what is happening inside the plant, to cells, which ones, auxin)
There are also heaps of other websites with information on the effects of auxin if you need it explained more.