05 Nutrition in Humans Worksheet

21 Biology Worksheet Chapter 6: Nutrition in Humans Name: _________________________ ( ) Class : _________ Date : _________ Section A Multiple Choice Questions Choose the most appropriate answer and write it in the corresponding box below. Qn 1 2 3 4 5 6 7 8 9 10 Ans Qn 11 12 13 14 15 16 Ans 1 Which of the following curves best represents the change in the glucose level of blood flowing through the following organs of a man who has starved for eight hours? 
 2 The acidic liquid in the stomach contains ________. A pepsin and mucus C maltase and pepsin B bile and pepsinogen D lipase and trypsin 3 If the pancreatic duct of a mammal became blocked, which symptom would the animal show? A increased bile in the blood C decreased blood insulin level B increased blood sugar level D decreased protein digestion 4 Pancreatic juice contains enzymes, which digest ________. 8 A proteins and carbohydrates C fats and carbohydrates B proteins and fats D proteins, fats and carbohydrates

22 5 The secretions listed below are all active in the mammalian alimentary canal. (1) Saliva (2) Gastric juice (3) Bile (4) Pancreatic juice (5) Intestinal juice Which secretions contain the enzyme amylase? A 1 only C 1 and 4 only B 2 only D 1 and 5 only 6 What would happen if a person’s bile duct became blocked? A Fat digestion would be reduced. B Fat digestion would stop. C Manufacture of bile would stop. D Protein digestion would stop. 7 Which region of the alimentary canal has the greatest surface area for absorption of food molecules? A colon C ileum B duodenum D stomach 8 The diagram shows the effect of pH on the activity of two enzymes in the human gut. In which regions of the alimentary canal would these enzymes be most active? Protease Amylase A colon stomach B duodenum colon C duodenum stomach D stomach duodenum 9 The diagram shows the structure of a villus in the small intestine. The arrows show the direction of flow of fluids. After a meal of fried chicken, where will fats be present in the largest amounts?

23 10 The diagram shows some food moving along the alimentary canal, by peristalsis. In which state are the muscles in the wall of the alimentary canal at point X? circular muscles longitudinal muscles A B C D contracting contracting relaxing relaxing contracting relaxing contracting relaxing 11 The diagram shows the blood supply to the liver and gut. What are X, Y and Z? artery portal vein vein A X Y Z B Y Z X C Z X Y D Y X Z 12 Where in the alimentary canal is most water absorbed? A colon B ileum C oesophagus D stomach

24 13 Five tubes containing cooked egg-white are set up as shown. Protease solutions of different pH are added to each tube. Which diagram shows the result of this experiment for a protease from the stomach? 14 The diagram shows part of the circulatory system. After a meal, which blood vessel will contain blood with the most glucose?

25 15 The graphs show the concentrations of glucose and insulin in the blood of a healthy person. Which graph shows the changes expected after a meal containing starch? 16 Four test-tubes are set up as shown. All four tubes are then placed in a water-bath at 37 oC for 20 minutes. What is the result? tube 1 2 3 4 A clear clear clear clear B clear cloudy cloudy clear C cloudy cloudy clear cloudy D cloudy clear cloudy clear Key ____ glucose ------- insulin

26 Section B Structured Questions 1 The figure below shows the event to which carbohydrates ( ), proteins ( ) and fats ( ) are digested as food passes through the alimentary canal of Man. The letters (A to F) represent successive parts of the alimentary canal. Examine the figure and answer the following questions. (a) Name the parts B and C. B __________________________ C _________________________ (b) (i) What brings about the start of digestion of carbohydrate molecules in part A of the gut? _____________________________________________________________________ (ii) Explain why the percentage of undigested protein molecules suddenly decreases in part C of the gut. _____________________________________________________________________ (iii) In which part of the gut (A to F) does most digestion occur? ______________________________________________________________________ (c) (i) In which part of the gut (A to F) would lipase be present and on which class of food would it act? Part __________________________________________________________________ Food _________________________________________________________________ (ii) In which part of the gut (A to F) is most water reabsorbed? ______________________________________________________________________

27 2 The figures represent the digestion of three nutrients. (a) Identify each of the following: (i) Nutrient A _______________________________________________________ (ii) Enzymes B _______________________________________________________ C _______________________________________________________ (iii) End products P _______________________________________________________ _______________________________________________________ Q _______________________________________________________ R _______________________________________________________ S _______________________________________________________ (b) Name a region of the alimentary canal where each of the enzymes B and C may be found. Enzyme B _______________________________________________________________ Enzyme C _______________________________________________________________ (c) Explain why it is necessary, during digestion, to change the nutrient molecules in the way shown in the figure. ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________

28 3 The figure shows a side view of the alimentary canal within a person’s abdomen. (a) On the figure, draw in the correct position and label the liver. (b) Complete the table below, identifying parts E and F. For each part, state one function and one structural feature which adapts it to the function you have mentioned. Part Name Function Structural feature E F (c) (i) What type of food is digested in the organ labelled G? ____________________________________________________________________ (ii) Describe the role of organ G in the process of digestion. ____________________________________________________________________ ____________________________________________________________________

29 4 The figure shows a blood vessel (Q) linking a part of the alimentary canal (P) with an organ (R) in the abdomen. (a) (i) Identify P, Q and R. P ________________ Q ________________ R _________________ (ii) What type of blood vessel is S? ________________________________________ (b) State the changes in the composition of the blood in Q shortly after a meal has been eaten which contains protein and carbohydrate. _________________________________________________________________________ _________________________________________________________________________ An athlete is about to take part in a race. (c) (i) How do the concentrations of materials in blood vessel S d