science prac help?

well in class we were doing this experiment when we get union skins under the microscope we then put methylene on them and put cover slips on that and blah blah blah anyways there was a couple of questions i didnt understand 1 was “why did the feild of view decrease?” another was”why did you [...]

i m going to become a student of bsc houners in bimedical science in d.u what is further scope in this feild?