Answer:
Chemical and mechanical digestive systems.
Explanation:
Chemical and mechanical digestions are the two systems that are involved in the digestion of food. Some parts of digestive system broken down food with mechanical force such as mouth whereas some food is broken down into smaller substances with the help of chemicals such as juices of pancreas, liver, and intestine. Both systems are very important for the complete digestion of food particles into simpler substances in order to absorb by the cells to produce ATP.
