Assertion : Food is to be absorbed from the alimentary canal, it has to be broken into smaller molecules.

Reason : The saliva contains an enzyme called salivary amylase that breaks down starch which is a complex molecule to give simple sugar. 

Both A and R are true and R is the correct explanation of A.

The correct answer is Option (1) –Both A and R are true and R is the correct explanation of A.

Food we ingest is its complex nature. If it is to be absorbed from the alimentary canal, it has to be broken into smaller molecules. This is done with the help of biological catalysts called enzymes. The saliva contains an enzyme called salivary amylase that breaks down starch which is a complex molecule to give simple sugar.

The food is mixed thoroughly with saliva and moved around the mouth while chewing by the muscular tongue .

From the mouth, the food is taken to the stomach through the food-pipe or oesophagus. The stomach is a large organ which expands when food enters it. The muscular walls of the stomach help in mixing the food thoroughly with more digestive juices.