Teach your students that facts and logic are the only way to plead a case. Whining is never allowed.
My students have made the case for eliminating tests in our school, even in math. In fact, when my students want to present a case to me, I know to be fully attentive so that I do not get caught by surprise. They are very good arguers, able to make their position fully understood. (However, I cannot remember them just arguing with each other or with us as parents.)
“Will my answer change?” was my standard reply to my children when they repeated a request. For them, that meant “end of discussion” — Mom never changes her mind, unless you can come up with enough facts and logic to present your issue. When the request had nothing to do with facts or logic, the issue passed peacefully away — they did not whine, and I did not have to scold. My daughter later used that same line successfully on college friends, who did not understand how to ask for anything without whining.
Many times my children have convinced me of the wisdom of changing our plans. Why do we need to answer the questions at the end of the chapter? If they have already told me about the book they just read, do they really need to get frustrated trying to write it all down into a stuffy book report (that I do not want to read anyway)? If they get truly grossed-out even thinking about dissecting, is it really necessary to do it? (I have lived my entire life without anyone asking me if I have dissected anything.)