1. 1
   A student is studying a sample of stomach wall under a microscope as part of a project on digestion. The sample shows three distinct types of tissue arranged in layers: an outer layer of muscle fibres, a middle layer containing cells that release fluid, and an inner lining of flat, closely packed cells facing the stomach cavity.

   (a)

   Which tissue in the stomach wall contracts to move food through the digestive system?

   [1 mark]

   • AGlandular tissue
   • BMuscular tissue
   • CEpithelial tissue
   • DXylem tissue

   (b)

   What is the main function of the glandular tissue found in the stomach wall?

   [1 mark]

   • ATo cover the inner and outer surfaces of the stomach
   • BTo contract and mix the stomach contents
   • CTo produce digestive juices such as enzymes and acid
   • DTo absorb digested food into the blood

   (c)

   The stomach is described as an organ made up of several different tissues. Explain what is meant by the term 'organ', using the stomach as your example.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A nutritionist is explaining to a class how food travels through the body after it is eaten. She describes a pathway involving several organs, starting with glands that add digestive juices to food, followed by an organ where food is churned and partly digested, then an organ where most digestion and absorption of soluble food happens, and finally an organ where water is absorbed from the remaining undigested material before it leaves the body.

   (a)

   Which organ system does the stomach belong to?

   [1 mark]

   • ACirculatory system
   • BNervous system
   • CRespiratory system
   • DDigestive system

   (b)

   Which organ in the pathway described by the nutritionist is responsible for producing bile?

   [1 mark]

   • ALiver
   • BSmall intestine
   • CPancreas
   • DLarge intestine

   (c)

   Name the organ in the pathway where absorption of soluble food occurs, and name the organ where water is absorbed from the undigested food to produce faeces.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   Doctors are investigating a patient whose digestive organs are affected by an autoimmune condition. Tests show that the glandular tissue in the patient's pancreas and salivary glands has been damaged and produces very little secretion, while the muscular tissue and epithelial lining throughout the digestive system remain completely normal.

   (a)

   A patient has a rare condition that damages the glandular tissue of the pancreas and salivary glands, but leaves the muscular and epithelial tissue in their digestive system unaffected. Suggest two problems this patient is likely to experience with digestion, and explain why each occurs.

   [3 marks]

   (b)

   The doctors confirm that this patient's digestive organs still contain three types of tissue: muscular, glandular and epithelial. Explain, in terms of tissues and organs, why an organ such as the stomach can still function partially even though one of its tissue types is damaged, and why this shows the importance of tissues working together in an organ.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A student carried out an investigation into how animal tissue type relates to function, using three unlabelled tissue samples taken from parts of the digestive system: Sample X contracted rhythmically when placed in a warm salt solution; Sample Y released a fluid when stimulated with a chemical signal; Sample Z formed a smooth, continuous, protective sheet of cells with no contraction or secretion observed.

   (a)

   A student carried out an investigation to find out how the type of animal tissue relates to its function. She was given three unlabelled tissue samples from the digestive system: Sample X contracted rhythmically when placed in a warm salt solution; Sample Y released a fluid when stimulated with a chemical signal; Sample Z formed a smooth, continuous, protective sheet of cells with no contraction or secretion observed. Using your knowledge of animal tissues, identify each sample and explain how the observations support your identification, and describe how these three tissue types combine to form an organ such as the stomach.

   [6 marks]

   (b)

   The student wants to repeat her investigation more rigorously so her conclusions are more reliable. Describe a suitable method she could use to test and compare Samples X, Y and Z fairly, including how she would keep the test fair and how she would judge whether each sample was contracting or secreting a fluid.

   [6 marks]

   Total for question 4: 12 marks

End of questions