1. (4 marks). What external features of birds and sharks are used as mechanisms for hunting or attacking prey? What is the function of these structures? 2. ( 3 marks). In terms of structures, how are the digestive tracts of birds and sharks similar? Name one structure for each of the shark and the pigeon that are found in one animal but not the other. Name one structure that is shared by the bird and grasshopper, but not the shark. 3. (3 marks). In terms of structures used for reproduction (external as well as internal) what similarities and differences do you see when examining the bird, shark, and crayfish?.