The English Parliament had controlled colonial trades, imports and exports since the beginning. But the americans weren't represented in the Parliament, so this went against the Bill of Rights of 1689, which forbid the imposition of taxes without the Parliament's approval. The increasing imposition of taxes in the second half of 18th century harmed the colonies' trade and economy, paying for wars on the other side of the Atlantic that had very little to do with them. So, they denied to keep paying for taxes unless they got direct representation in the Parliament. With this, the inhabitants of the colonies were claiming their equality with the inhabitants of the metropolis. It eventually led to the American Revolution, since the English government refused to listen to the colonies' demands.
The notion of "no taxation without representation" tied the colonies together against a common enemy, setting the foundations of what it would become the United States of America.
I have no idea what AP English 11 is like.
I think AP Bio is a difficult class to take. Bio may seem easy, but AP Bio is a whole different world. I would not recommend taking it unless you have a very good work ethic and you enjoy biology.
Don't take an AP class just to take one, choose one that you are intrested in.