I believe the answer is comparative anatomy. It is the study of the similarities and differences in the structures of different species. Similar body parts may be homologies or analogies, such that both provide evidence of evolution. Similarities in embryos are evidence of common ancestry. For example all vertebrates embryos have gill slits and tails.
Products are released from the active site of an enzyme during a chemical reaction. Active sites directly bind to the substrates and carry out the reaction. It is this site, where product if formed, and after completion of the reaction, are released. It possesses catalytic group for making and breaking the bonds, for carrying out the reaction.
