What's a good question to use the scientific method on?

I never thought I would use Fluther for homework help, but I have no idea what question to use to go through the scientific method.

These are my directions:

1) Propose a question of some subject that involves Biology.
2) Create a hypothesis.
3) What experiments would you use to answer that/those questions?

And then I have to go through the scientific method using my question.

So, my question is, what is a good topic or question that you would use when using the scientific method? :)