80% of the final exam will be based on the one lecture you missed..?

maybe for weekly examinations. But for final exams no. And if you are lucky enough and the one you missed is not important then its less than 10% me as a student i sometimes will miss a lecture if i already know it or if i know its just stupid. like for an example studying the parts of the microscope which is basically given almost ever semester.

I've heard that saying before I entered college. I'm not sure if it is true or not but it definitely motivates me to attend every lecture so I don't miss any crucial information that might end up on an important exam. I'm not sure how much attending class helps though when you end up falling asleep as I always do.

It happens but only during weekly examinations where you were absent for 1 or 2 days. But during final examinations, No. Possibly we had coped it up already even though we were absent for some several days. Final examinations has a wider coverage and I think we are giving much more preparations in it. Considering the researching of our missed lessons from our classmates or even asking special lecture or borrowing journals from our teachers. Thanks

It has never happened to me, but I never skipped any class..well it's just that i dun wanna miss any lessons as i'm interested to gain new knowledges in every class..