7.5. Absorption
A subsection of Biology, 0610, through 7. Human nutrition
Listing 10 of 58 questions
For Examiner's Use shows a section of a villus at two different magnifications. ×270 ×110 red blood cells muscle tissue Label the structures shown in . Write the labels in the boxes in . For Examiner's Use Suggest the role of the muscle tissue shown in the villus in . shows an experiment to investigate the uptake of glucose by cells of the villi. • Two leak-proof bags were set up. • One bag was made from artificial partially permeable membrane (Visking tubing). • The other bag was made from a piece of small intestine containing living cells, with its inner surface inside the bag. • The bags were filled with equal volumes of a dilute glucose solution. • The bags were suspended in the same glucose solution for two hours. • After two hours, the volumes of the bags were measured and the contents were tested for the concentration of glucose. glass rod to support bags dilute glucose solution maintained at 37 °C 10 cm length of small intestine containing living cells 10 cm length of artificial partially permeable membrane (Visking tubing) beaker dilute glucose solution inside bags Inside the bag made from small intestine the volume and concentration of the glucose solution decreased. There were no changes to the volume and concentration in the Visking tubing bag. State and explain the process responsible for the decrease in the glucose concentration in the bag made from small intestine. For Examiner's Use After two hours there was less water in the bag made from small intestine. The volume of water in the bag made from small intestine decreased, but the volume in the bag made from Visking tubing did not change. Explain why. An investigation studied the flow of water into and out of the human alimentary canal. Table 1.1 shows the results. Table 1.1 water into the alimentary canal water out of the alimentary canal source of water volume of water / dm3 per day method of water loss volume of water / dm3 per day water from diet 2.5 stomach to the blood 0.00 saliva 1.5 small intestine to the blood 9.00 gastric juice 2.4 large intestine to the blood 0.85 bile 0.8 in the faeces 0.15 pancreatic juice 0.8 intestinal secretions 2.0 Name the part of the alimentary canal that secretes most water in a digestive juice. Name the part of the alimentary canal that absorbs most water. For Examiner's Use Explain why water is added to food by the secretions shown in Table 1.1. Explain why it is important that water is absorbed in the alimentary canal.
0610_s11_qp_31
THEORY
2011
Paper 3, Variant 1
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Questions Discovered
58