Are these considered biographies/autobiographies?

I'm sure that your school would accept The Diary of Anne Frank. If your teacher protests this fall, tell him/her that The Diary is a first-hand account of a girl's life, beliefs, feelings, and day-to-day cirstances. It's true that it's a fragmented portion of her life, but it's definitely the hardest part of her life. The diary's pivotal to her development as a person (even if she didn't live long past her time in the Annex).