Bulls' eyes
In biology, we were given bulls' eyes to dissect. Obviously this was an important lesson for anyone who was looking for a career in bovine opthalmology. For the rest of us, we were happy to discover that the stuff at the back (presumably optic nerves and shit) was very sticky. This meant that by the time the teacher got back from break, there were twenty bulls' eyes stuck to the blackboard glaring down at her.
written by An*y Man*h, approved by Log

Our scalpels as sharp as the average plastic ruler, so that the overall effect of attempted dissection would be a thick paste and a teacher's disbelief that none of us could "find the lens".
written by Ja*k H*den, approved by Log

Teacher training notes. Pigs liver dissection:

Don't warn your class at the beginning of the lesson to ensure they do not leave any bits of liver lying around due to the stench it makes when it rots. They will simply spend the entire lesson cutting the liver up and hiding it around the classroom and in peoples' pencil cases.
written by an*ny*ou* use*, approved by Mansh