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The diagram shows the digestive system of a human - Edexcel - GCSE Biology - Question 4 - 2014 - Paper 1
Question 4
The diagram shows the digestive system of a human. (a) Describe the role of the mouth in digestion. (b) Villi are structures in the small intestine. (i) Which o... show full transcript
Worked Solution & Example Answer:The diagram shows the digestive system of a human - Edexcel - GCSE Biology - Question 4 - 2014 - Paper 1
Step 1
Describe the role of the mouth in digestion.
Answer
The mouth plays a critical role in the digestive process by initiating both mechanical and chemical digestion.
Firstly, the teeth chop and grind the food into smaller pieces, making it easier to swallow and increasing the surface area for enzymes to act upon.
Secondly, saliva is secreted, which contains the enzyme amylase. This enzyme begins the breakdown of starch into simpler sugars like maltose, facilitating further digestion. The saliva also moistens the food, forming a bolus that can be easily swallowed.
Step 2