11.2. Antibodies and vaccination
A subsection of Biology, 9700, through 11. Immunity
Listing 10 of 181 questions
Much success was made in reducing the number of cases of malaria between 2000 and 2015. Explain how malaria is transmitted. Diagnostic test strips for malaria contain monoclonal antibodies. The test strips detect antigens produced by the pathogens that cause malaria. shows stages in the production of monoclonal antibodies. The information in three of these stages is incomplete. Complete . malarial antigen injected into mouse immune response occurs in mouse plasma cells extracted from spleen of mouse plasma cells with myeloma cells formation of cells myeloma cells specific divide to form many plasma cells shows two diagnostic test strips for malaria. MALARIA C T S A negative result MALARIA C T S A positive result • A sample of blood from a person suspected of having malaria is put into the well labelled S. • A buffer solution is put into the well labelled A. • The buffer solution moves the blood towards the results window. • A line at position C indicates that the test is working correctly. • A line at position T indicates a positive result for malaria. State three advantages of using test strips for malaria, such as those shown in . The highest number of cases of malaria occur in sub-Saharan Africa and South-East Asia. Discuss the factors that determine the global distribution of malaria.
9700_s21_qp_21
THEORY
2021
Paper 2, Variant 1
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Outline the hybridoma method for the production of a monoclonal antibody. Herceptin is a monoclonal antibody used in the treatment of some breast cancers. It binds strongly to molecules of a receptor protein, HER2, that is produced in abnormally large quantities in the plasma (cell surface) membranes of about 30% of human breast cancers. Investigations have been made into the most effective way to use Herceptin to treat breast cancer. One experiment investigated the ability of different treatments to induce cell death in breast cancer cells. Herceptin and X-ray treatment were used both separately and together. The results are shown in . 1.0 2.0 ability to induce cell death / arbitrary units no treatment Herceptin only X-ray treatment only Herceptin and X-ray treatment With reference to , compare the effects on breast cancer cells of the different treatments calculate the percentage increase in the ability to induce cell death of using Herceptin and X-ray treatment compared with using Herceptin only. Show your working. A second experiment investigated the effect of increasing doses of X-rays on the survival of breast cancer cells in the presence and absence of Herceptin. The results are shown in . 1.0 10.0 mean percentage of cells surviving (log scale) absorbed dose of X-rays / J kg–1 X-rays and Herceptin X-rays With reference to , compare the effects of increasing doses of X-rays on cells in the presence and absence of Herceptin suggest an explanation for the effect of Herceptin.
9700_w08_qp_4
THEORY
2008
Paper 4, Variant 0
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Many tumours release a protein growth factor called VEGF. This is a chemical signal that causes nearby blood vessels to grow new branches into the tumour. The monoclonal antibody, bevacizumab (Avastin®), specifically binds to VEGF. Suggest how Avastin® can prevent the growth and spread of a tumour. Avastin® is made by the hybridoma method. State: the antigen that is injected into a mouse to produce this monoclonal antibody what is meant by a hybridoma. The monoclonal antibody made by the hybridoma method is modified to obtain humanised mouse antibody. This type of antibody molecule resembles those produced by humans. Suggest advantages of using humanised mouse antibody rather than mouse antibody. A second monoclonal antibody, ranibizumab (Lucentis®) is used to treat eye diseases. Lucentis® is a fragment of Avastin® and is shown in . antigen binding site Complete to show a molecule of Avastin®. Labels are not required.
9700_w14_qp_41
THEORY
2014
Paper 4, Variant 1
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Many tumours release a protein growth factor called VEGF. This is a chemical signal that causes nearby blood vessels to grow new branches into the tumour. The monoclonal antibody, bevacizumab (Avastin®), specifically binds to VEGF. Suggest how Avastin® can prevent the growth and spread of a tumour. Avastin® is made by the hybridoma method. State: the antigen that is injected into a mouse to produce this monoclonal antibody what is meant by a hybridoma. The monoclonal antibody made by the hybridoma method is modified to obtain humanised mouse antibody. This type of antibody molecule resembles those produced by humans. Suggest advantages of using humanised mouse antibody rather than mouse antibody. A second monoclonal antibody, ranibizumab (Lucentis®) is used to treat eye diseases. Lucentis® is a fragment of Avastin® and is shown in . antigen binding site Complete to show a molecule of Avastin®. Labels are not required.
9700_w14_qp_42
THEORY
2014
Paper 4, Variant 2
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Questions Discovered
181