0610_s13_qp_31
A paper of Biology, 0610
Questions:
6
Year:
2013
Paper:
3
Variant:
1

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For Examiner's Use shows the human head, neck and thorax. A B C D K J H G F E Complete Table 1.1 by writing one letter from to identify the named structures. The first one has been done for you. Table 1.1 structure letter from left lung D bronchus diaphragm intercostal muscle rib trachea For Examiner's Use In an investigation, a student breathed in and out of the apparatus shown in . Valve X opens to allow atmospheric air in while valve Y is closed. When the student breathes out, valve X is closed and valve Y opens to allow breathed out air into the bag. atmospheric air valve X valve Y bag for collection of breathed out air breathed out air air breathed out The student breathed in and out four times. The bag was sealed and the volume of air inside the bag was measured. A sample of air from the bag was analysed for the percentage composition of oxygen, carbon dioxide and nitrogen. The student then did some vigorous exercise for five minutes. After the exercise, the student repeated the procedure. The results of the investigation are shown in Table 1.2. Table 1.2 sample of breathed out air before exercise after exercise total volume of air collected in bag / cm3 2 000 15 000 mean volume of air per breath / cm3 percentage of oxygen / % 17.2 15.3 percentage of carbon dioxide / % 3.6 5.5 percentage of nitrogen / % 74.9 74.7 For Examiner's Use Calculate the mean volume of air per breath after exercise. Write your answer in Table 1.2. Show your working. Suggest one way, not shown in Table 1.2, in which the student’s breathing changed after exercise. The figures in Table 1.2 for the percentage composition of air in each sample do not add up to 100 %. Name one other gas that would be present in both samples of air. The results for oxygen and carbon dioxide in the samples of breathed out air taken before and after exercise are different. Describe and explain these differences.
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For Examiner's Use shows the human female reproductive system. X R S T V W Table 3.1 shows four functions of the female reproductive system. Complete the table by: • naming the part of the system that carries out each of the functions; • using the letters from to identify the part of the system named. One row has been completed for you. Table 3.1 function name of organ letter from production of gametes site of implantation site of fertilisation dilates during birth cervix V The hormone FSH is important in regulating the menstrual cycle. State the target organ of FSH. State one effect of FSH. For Examiner's Use The drug clomiphene is given to women who have difficulty in having children. The drug increases the secretion of FSH. As part of treatment for infertility, a woman was given clomiphene for five days. The concentration of oestrogen in her blood was measured every day for 27 days. The results are shown in . concentration of oestrogen in the blood / arbitrary units time / days clomiphene taken Describe the changes in oestrogen in the blood over the 27 days. You will gain credit if you use results from in your answer. For Examiner's Use Doctors thought that ovulation occurred around day 15. Explain what is meant by the term ovulation. The treatment was not successful on the first occasion. As an alternative to this treatment, women may be offered in vitro fertilisation (IVF) treatment. In IVF treatment, an egg is fertilised outside the body and the resulting embryo is placed into the uterus. Describe what happens when an egg is fertilised by a sperm. For Examiner's Use Some embryos produced by IVF do not develop because there are problems with their chromosomes, such as having the wrong number. Define the term chromosome. State the correct number of chromosomes that should be in a cell of a human embryo.
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For Examiner's Use Enzymes are necessary for many biological processes, such as the digestion of fat. fat + water fatty acids + glycerol lipase Explain why enzymes are necessary for biological processes. Lipase, protease and amylase are enzymes secreted into the alimentary canal. Name one organ that secretes each enzyme. Choose your answers from this list. colon gall bladder liver oesophagus pancreas rectum salivary glands stomach You can use each organ only once. lipase protease amylase For Examiner's Use A group of students investigated the digestion of fat in milk. • They added an alkaline solution to the milk. • They divided the milk into four test-tubes. • They added lipase and bile salts to some of the test-tubes, as shown in Table 5.1. They did this at the same time for each test-tube. • They kept all test-tubes at 40 °C. • After 5 minutes, they added Universal Indicator solution to each test-tube. Table 5.1 test-tube contents colour of pH indicator after 5 minutes at 40 °C A milk, alkaline solution, lipase and bile salts orange B milk, alkaline solution, bile salts and water blue C milk, alkaline solution, lipase and water yellow D milk, alkaline solution and water blue shows the colour of the indicator at different pH values. pH red orange yellow green blue purple Explain why test-tube D was included in the investigation. For Examiner's Use Explain why the colour in test-tube A was orange. Explain the results for test-tubes B and C. test-tube B test-tube C
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