digestion II.doc

F.4 Biology Class ExerciseDigestion of food IIName: _Class: _Group: _1.The diagrams below show some parts of the human digestive system. ( A to H )lonrectumileumFAFFEEGAFFEEHAFFEE.BCDEA(a)Using the letters in the diagram ONLY, complete the table below :DescriptionsPart(s)1. Peristalsis occurs in2. They belong to the alimentary canal3. They secrete digestive enzymes4. It secretes the enzyme lipases only5. They absorb water from food6. It absorbs most water from food.7. It absorbs digested nutrients.8. It absorbs water from undigested food.9. It secretes a digestive juice with no enzyme.10. The wall contains mucus11. Mechanical digestion of food occurs in12. It secretes bile13. It contains bacteria that produce vitamin K.14. It is the longest part of the alimentary canal.2.Complete the following table to show where starch, protein and fat are digested in the alimentary canal.Put a in the correct boxes.starch proteinfat1. Mouth2. Oesophagus3. Stomach4. Small intestine5. Large intestineLevel II : Questions for discussion : ( 12 marks )1(a)Which part of the alimentary canal is the longest ? _ ( 1 mark )(b) Can you guess how long it is ? _ m ( 1 mark )(c)Why is it so long ? ( 4 marks )_2.The inner surface of the whole alimentary canal is covered by a layer of mucus ( sticky, watery liquid ).(a)Suggest two general functions of this layer of mucus. ( 2 marks )_2(b)The stomach has the thickest layer of mucus. Do you know why ? ( 2 marks )_3.The wall of the whole alimentary canal is made up of muscles. Suggest a function of