9700_s22_qp_21
A paper of Biology, 9700
Questions:
6
Year:
2022
Paper:
2
Variant:
1
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1
and are photomicrographs showing the distribution of tissues in the lungs. is a photomicrograph of a section through part of the lungs. is a high-power view of the area indicated on . A B section enlarged in C D A State the names of the tissues A, B and D. A B D Describe the role of the glands labelled C in in maintaining the health of the gas exchange system. Hyperventilation occurs when a person breathes too fast or too deeply. The effects of hyperventilation are: • a decrease in the partial pressure of carbon dioxide in alveolar air • an increase in the pH of the blood. shows the change in the oxygen dissociation curve as a result of hyperventilation. percentage saturation of haemoglobin with oxygen partial pressure of oxygen (pO2) / kPa Key pH 7.4 pH 7.7 State the percentage saturation of haemoglobin at a pO2 of 4.0 kPa. pH = 7.7 kPa pH = 7.4 kPa Use the information in to state and explain the effect of hyperventilation on the supply of oxygen to the respiring tissues.
8. Transport in mammals  →  8.2. Transport of oxygen and carbon dioxide
9. Gas exchange  →  9.1. The gas exchange system
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2
B-lymphocytes are activated to form plasma cells during immune responses. is a drawing of a plasma cell made from a transmission electron micrograph. R P S Q T State the name of the process that is occurring at T. Complete Table 2.1 to show the names and functions of the cell structures labelled P, Q, R and S in the plasma cell shown in . Table 2.1 cell structure in name of cell structure function of cell structure in plasma cell P Q R S Plasma cells can be used in the commercial production of some monoclonal antibodies. The method of production is known as the hybridoma method. Outline the steps in the production of monoclonal antibodies by the hybridoma method. Antibodies can be collected from human blood donors and used to treat people that may have been infected with a pathogen. This prevents them becoming ill with the disease. Explain why this treatment does not prevent people becoming ill if they are infected again with the same pathogen.
11. Immunity  →  11.2. Antibodies and vaccination
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3
A tyrosine kinase receptor (TKR) is a protein complex found in the cell surface membrane of mammalian cells. TKR has two components involved in the process of cell signalling: • a receptor for the signalling molecule • an enzyme that catalyses the transfer of a phosphate group from ATP to an intracellular protein. is a diagram to show how TKR is involved in cell signalling. outside cell activated intracellular protein signalling molecule receptor component enzyme component ATP ADP Most enzymes are specific to one reaction. With reference to , explain how the structure of an enzyme provides its specificity. The drug GNF-5 is used in the treatment of some cancers. GNF-5 affects the activity of TKR by binding to the enzyme component of the complex. Researchers investigated the effect of GNF-5 on the activity of TKR using different concentrations of ATP solution. In an experiment the activity of TKR was measured with no GNF-5 and with GNF-5. The results are shown in . 0.1 concentration of ATP / μmol dm–3 activity of TKR / arbitrary units Key with no GNF-5 with GNF-5 The researchers concluded that GNF-5 acts as an inhibitor of the enzyme component of TKR and that it is a competitive inhibitor. Use to provide evidence for these conclusions. A mutation of the gene coding for TKR results in changes to the enzyme component of TKR. This altered form of TKR is known as T315L. The effect of GNF-5 on the activity of T315L was also investigated. The results of this investigation are shown in . 0.1 concentration of ATP / μmol dm–3 activity of T315L / arbitrary units Key with no GNF-5 with GNF-5 Use and to: State how the activity of T315L differs from TKR when no GNF-5 was present. State how the effect of GNF-5 on T315L differs from the effect of GNF-5 on TKR.
14. Homeostasis  →  14.1. Homeostasis in mammals
3. Enzymes  →  3.2. Factors that affect enzyme action
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4
Adipocytes are cells found in adipose tissue in mammals. These cells absorb glycerol and fatty acids to make triglycerides for long-term storage. a shows a glycerol molecule and three fatty acids. b shows the triglyceride molecule formed from these components. CH2 CH2 OH CH2 OH CH OH OH + C O CH2 OH C O CH2 OH X Y Z C O CH2 CH CH2 CH2 O C O CH2 O C O CH2 O C O a b State the name of the bonds that form between glycerol and fatty acids. When a bond forms between glycerol and a fatty acid, water is a product of the reaction. State the name given to this type of reaction. Describe the differences between the fatty acids, X, Y and Z, shown in a. State reasons why triglycerides are described as hydrophobic. Explain why triglycerides are not suitable as a component of cell surface membranes.
2. Biological molecules  →  2.2. Carbohydrates and lipids
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5
Infectious diseases are caused by pathogens and are described as transmissible diseases. Explain what is meant by the term transmissible. Vibrio cholerae is the bacterium that causes cholera. is a transmission electron micrograph of V. cholerae. flagellum A student wanted to know the actual length of the flagellum shown in . State the information that is needed so that the student can calculate the actual length of the flagellum. Table 5.1 shows data on large outbreaks of cholera that occurred in seven countries in 2019. The case-fatality rate is the number of deaths as a percentage of the number of cases. Table 5.1 country number of cases of cholera number of deaths from cholera case-fatality rate / % Cameroon 1 307 4.2 DR Congo 29 087 1.7 Haiti 0.4 Kenya 5 150 0.8 Somalia 9 968 0.5 Sudan 3.2 Yemen 2 260 495 Complete Table 5.1 by calculating the case-fatality rate for Yemen. Suggest why large outbreaks of cholera occurred in the countries listed in Table 5.1, but there were very few cases in most other countries.
10. Infectious diseases  →  10.1. Infectious diseases
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6
Cotransporter proteins are membrane proteins found in companion cells of phloem tissue. Messenger RNA (mRNA) is the molecule in cells that carries genetic information in the DNA that codes for cotransporter proteins to the sites of protein synthesis in the cytoplasm. Complete Table 6.1 to compare the structure of a molecule of mRNA with the structure of a molecule of DNA. Table 6.1 feature mRNA DNA names of four bases name of pentose sugar present number of strands shows the events that occur in the nucleus of a companion cell in phloem tissue to synthesise molecules of mRNA. DNA mRNA stage 1 stage 2 Name stage 1 shown in . Describe what happens at stage 2, shown in , to shorten the length of the RNA molecule. Cotransporter molecules are proteins produced in companion cells. shows what happens in the cytoplasm of a companion cell to a transfer RNA molecule before the cotransporter proteins can be produced. C C G C C G H H3N+ C C O O– H H H3N+ C C O O– H Describe the role of the transfer RNA shown in in the synthesis of a cotransporter protein. Outline the role of cotransporter proteins in companion cells.
7. Transport in plants  →  7.2. Transport mechanisms
6. Nucleic acids and protein synthesis  →  6.2. Protein synthesis
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