11. Immunity
A section of Biology, 9700
Listing 10 of 303 questions
A vaccine, NicVAX, is being developed to help people stop smoking tobacco. Injection of NicVAX into the body causes production of antibody molecules that bind to nicotine. Outline the immune response that leads to the production of these anti-nicotine antibodies. Mice injected with NicVAX produce B-lymphocytes that mature into cells responsible for the production of antibody (plasma cells). Outline how these B-lymphocytes can be used to produce monoclonal antibody. Tobacco smoking during pregnancy has adverse side-effects on the developing fetus. An investigation was carried out to find out whether vaccinating pregnant women with NicVAX might offer some protection for the developing fetus. Two different monoclonal antibodies, produced in response to NicVAX, were used in this investigation: • Nic-IgG • Nic311. Nicotine, or nicotine plus one of the monoclonal antibodies, was injected into the maternal circulation. The concentrations of nicotine in the fetal circulation were measured at intervals. The results of the investigation are shown in Fig 2.1.              WLPHPLQXWHV QLFRWLQHFRQFHQWUDWLRQ LQIHWDOFLUFXODWLRQQJFP²     QLFRWLQH QLFRWLQH  1LF QLFRWLQH  1LFOJ* With reference to , describe the results obtained for nicotine only. Discuss the extent to which these results support the idea that vaccination with NicVAX could protect the developing fetus of a woman who smokes tobacco. State one medical use of monoclonal antibodies, other than their use in producing vaccines.
9700_w15_qp_43
THEORY
2015
Paper 4, Variant 3
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A person’s blood group is determined by antigens present on the red blood cells. The table shows the antigens and antibodies in the blood of people with different blood groups. blood group antigens on red blood cells antibodies in plasma A A antibodies to B B B antibodies to A AB A and B neither O neither antibodies to A and B During a blood transfusion, it is essential that the recipient’s blood does not contain antibodies to the donor’s blood. Which blood group can be given to a person with blood group AB?
9700_w16_qp_11
MCQ
2016
Paper 1, Variant 1
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Measles is a highly infectious disease. Name the pathogen that causes measles. The number of cases of measles is reported to the World Health Organization (WHO) by countries throughout the world so that global data are collected. shows the global data collected between January 2008 and December 2012. Jan 2008 Mar May Jul Sep Nov Jan 2009 Mar May Jul Sep Nov Jan 2010 Mar May Jul Sep Nov Jan 2011 Mar May Jul Sep Nov Jan 2012 Mar May Jul Sep Nov 10 000 15 000 20 000 25 000 number of cases Key Africa Rest of the world 30 000 35 000 40 000 45 000 Use the data in to describe the pattern shown in the number of cases of measles reported to the WHO between January 2008 and December 2012. The WHO is coordinating a vaccination campaign to reduce the number of cases of measles. Between seven to ten days after receiving the vaccination for measles the concentration of antibodies in the blood begins to increase. Describe what happens in the body after the injection of a measles vaccine until the concentration of antibodies in the blood begins to increase. Explain why countries that have established vaccination programmes still have cases of measles.
9700_w16_qp_23
THEORY
2016
Paper 2, Variant 3
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Myasthenia gravis is a condition that results in muscle weakness by affecting the immune response. Explain what is meant by the term immune response. Myasthenia gravis is an autoimmune disease which disrupts a cell signalling pathway involving muscle cells. Suggest how the immune system acts to disrupt this cell signalling pathway. Enzyme Y is found in the cell surface membrane of muscle cells. Enzyme Y acts to break down the cell signalling molecules which trigger muscle contraction when they are no longer needed. Using the induced fit hypothesis of enzyme action, explain how enzyme Y breaks down the cell signalling molecules. Rituximab is a monoclonal antibody used in the treatment of myasthenia gravis. Rituximab acts against the cell surface membrane protein CD20. This protein is found on the surface of the B-lymphocytes that cause myasthenia gravis. Explain the advantages of using monoclonal antibodies in the treatment of diseases such as myasthenia gravis.
9700_w19_qp_21
THEORY
2019
Paper 2, Variant 1
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Questions Discovered
303