yeah, of course.
If any of those was the case, then there would be drops every now and then in the pass-rate or average pointscore or whatever.
Learning has been tailored to the exams for years, and the "doss subjects" are only "doss" because the answers to the questions are subjective. In Physics and Maths (etc), you can say whether an answer is right or wrong, but in arts and essay-based subjects it goes on how the "Grade descriptions" are interpreted. "Competently uses quotations" could mean that the candidate has to be able to use 2 quotations in the essay and comment on them, or, it could mean that the candidate has to use quotations to back up every point he makes, and then comment on them in a terse and cogent manner, showing that he understands implied meanings and subtlities..