1. 1
   A GCSE class is studying a diagram-free description of the human digestive system, which consists of the alimentary canal (mouth, oesophagus, stomach, small intestine and large intestine) and associated organs (salivary glands, pancreas, liver and gall bladder).

   (a)

   A student is describing the human digestive system. Which structure is part of the alimentary canal rather than an associated organ?

   [1 mark]

   • ASalivary gland
   • BPancreas
   • CSmall intestine
   • DLiver

   (b)

   Which process describes the movement of digested food molecules from the small intestine into the blood?

   [1 mark]

   • AAbsorption
   • BEgestion
   • CIngestion
   • DAssimilation

   (c)

   State two functions of the organs of the digestive system, other than absorption, referring to the terms ingestion, digestion, assimilation and egestion.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A dentist is explaining tooth structure and function to a patient during a routine check-up, describing how different teeth carry out physical digestion.

   (a)

   A dentist examines a patient's tooth and finds decay reaching the layer containing nerves and blood vessels. Which layer has been reached?

   [1 mark]

   • AEnamel
   • BDentine
   • CCement
   • DPulp

   (b)

   Which type of tooth is adapted for tearing food?

   [1 mark]

   • AIncisor
   • BCanine
   • CPremolar
   • DMolar

   (c)

   Explain how the physical digestion carried out by teeth helps chemical digestion occur more effectively later in the digestive system.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A researcher is studying how the stomach contributes to the physical digestion of a meal, alongside the action of bile released into the small intestine.

   (a)

   A researcher observes muscular contractions in the wall of the stomach that churn its contents. Describe the role of the stomach in physical digestion and state one other function of the stomach.

   [3 marks]

   (b)

   Fats and oils in the meal reach the duodenum and are emulsified by bile before chemical digestion. Describe the role of bile in physical digestion of fats and oils, and explain why this role is important for enzyme action.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A biology class is debating the statement that physical digestion is unnecessary since chemical digestion is what changes food molecules.

   (a)

   A student claims that 'physical digestion is not really necessary because chemical digestion is what actually breaks down food molecules.' Evaluate this claim by explaining what physical digestion is, giving two examples of physical digestion in the human digestive system, and explaining why physical digestion is essential for effective chemical digestion.

   [6 marks]

   (b)

   Describe the structure of a human tooth and explain how the structures of incisors, canines, premolars and molars are each adapted to their specific roles in physical digestion.

   [6 marks]

   Total for question 4: 12 marks

End of questions