Help please. Biology aqa asWatch
Also you do need to know about the different types of microscopes (I did it last year)
although it isn't 100% necessary to know topics that aren't on the spec, because of the high proportion of application questions in the test i would definitely recommend having at least a basic understanding of associated topics. It's not worth doing badly in the exam because you couldn't be bothered to do a bit of extra reading or take in the additional information from your teacher.
Also you do need to know about the different types of microscopes (i did it last year)