Without trying to give you more information than just the basics to help you along your way...
1. That's entirely up to you. I can certainly think of ways to demonstrate the basic idea that would be encapsulated in the sequences without such, but I can also see how separate ones would be helpful in demonstrating what you have in mind, design-wise.
2. You don't
need to do anything.

However, that said, I feel it is probably best to demonstrate how you intend the application client to fit into the equation.
Remember, you can tackle this any way you see fit, as long as it meets the requirements set out by the description and you document your assumptions, etc.