Dissection means to cut open the animal in order to ascertain the structure of it parts. Dissection is a standard laboratory technique in biology and pathology. To dissect is to cut up a body so as to reveal its structure. The body could be that of a human, an animal, or a plant. Dissections are regularly done in autopsies to help determine the cause of death. They are done by zoologists to find out the internal structure of animal bodies. The comparative anatomy of animals, revealed by dissections, gives clues as to their evolutionary relationships.