Question

Why do you suppose many different structures are needed by the digestive system?

Answer 1

digestion is not restricted to any one structure as it involves many complex processes as food should be broken down into simpler compounds, absorption and movement of undigested food should be done,this can't be done with help of only one structure
so digestive system is associated with many organs.


hope it helps you..

Answer 2

The food that the system processes is made of different things (fats, carbs ,proteins, minerals, fiber, etc.) and it is in different forms (solid, liquid, mush, etc.) naturally you need different tools to process different materials.