9700_w10_qp_22
A paper of Biology, 9700
Questions:
6
Year:
2010
Paper:
2
Variant:
2
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1
Protein production involves a complex sequence of events and a number of cell structures. The first column in Table 1.1 shows some of the events that occur in the production of a protein in a cell and its eventual release from the cell. Table 1.1 event sequence of events cell location exocytosis protein modification secretory vesicle formation transcription translation In Table 1.1, write the sequence in which the events occur, using 1 as the first process in the sequence. From the list A to F below, choose one cell location for each event and write the letter in Table 1.1. Each letter may be used once, more than once, or not at all. A Golgi apparatus B lysosome C nucleus D rough endoplasmic reticulum E smooth endoplasmic reticulum F plasma (cell surface) membrane For Examiner’s Use Describe the process of exocytosis. One example of protein modification is the removal of the first amino acid, methionine, from a newly formed polypeptide chain to make a functioning protein. The DNA nucleotide sequence that specifies the amino acid methionine is TAC. State the mRNA nucleotide sequence that is complementary to the DNA sequence for methionine. Suggest two other ways in which the polypeptide chain is modified to produce the functioning protein.
6. Nucleic acids and protein synthesis  →  6.2. Protein synthesis
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2
For Examiner’s Use Malaria is an infectious disease that is considered by the World Health Organization to be a disease of worldwide importance. Explain what is meant by the term infectious. Name one species of organism that causes malaria. Explain the significance of the following statements in the control of malaria. The female Anopheles mosquito has been more closely studied with regard to malaria than the male Anopheles mosquito. The infective stages of the malarial organism are present in anti-coagulant produced by the mosquito. After circulating in the blood for a short time, the pathogen enters liver cells of the newly infected person and then enters red blood cells. For Examiner’s Use Discuss the factors that determine the distribution of malaria worldwide.
10. Infectious diseases  →  10.1. Infectious diseases
11. Immunity  →  11.2. Antibodies and vaccination
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3
For Examiner’s Use Enzymes are globular proteins that catalyse metabolic reactions. Describe the features of globular proteins. Enzymes can be used to remove cell walls from plant and fungal cells. The cells are incubated in a solution that contains a mixture of enzymes. Suggest an explanation for the fact that a different mixture of enzymes is required to remove the walls of plant cells compared to the walls of fungal cells. Explain why, when plant cells are incubated with enzymes to remove their cell walls, it is important to maintain an optimum pH. For Examiner’s Use A student carried out an investigation into osmosis using red blood cells. Red blood cells were placed in sodium chloride solutions at five different concentrations. For each concentration, a sample was added immediately to a microscope slide and the cells were viewed using a light microscope for a period of time. The observations recorded are shown in Table 3.1. Table 3.1 concentration of salt solution / % observation of red blood cells 0.0 swell and burst, numbers decrease 0.4 increase in size 0.9 remain the same size 1.5 decrease in size 3.0 smaller and shrivelled Explain, in terms of water potential and osmosis, the results that the student obtained. For Examiner’s Use The student also carried out a similar investigation using plant cells with cell walls removed. These cells were suspended in a 12% mannitol solution so that the water potential inside and outside of the cells was equal. is a photomicrograph of these cells. The student removed a sample of these cells. The sample was placed into distilled water and was viewed using a light microscope. Describe what you would expect the student to observe and explain why this would not occur with normal plant cells.
4. Cell membranes and transport  →  4.2. Movement into and out of cells
3. Enzymes  →  3.2. Factors that affect enzyme action
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4
For Examiner’s Use is an incomplete flow chart showing some of the events of the primary immune response that occur after a person has been given a vaccine. dead pathogen in phagocytosis by cell presenting on its surface recognition and binding by specific activation, then cell division by produce and release antibodies secrete cytokines Choose the correct term from the list below to complete . lymphocytes antigens mitosis vaccine Th-lymphocytes plasma cells macrophages For Examiner’s Use Explain why the person is unlikely to become ill if they are infected by the same pathogen some months later. Some parents decide that their children should not take part in a vaccination schedule. Suggest how a country-wide vaccination schedule can give protection against infection to unvaccinated children.
11. Immunity  →  11.1. The immune system
11. Immunity  →  11.2. Antibodies and vaccination
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5
For Examiner’s Use State the term that applies to each of the descriptions to . Storage polysaccharide in animals made of chains of 1,4 linked α-glucose with 1,6 linkages forming branches. A plant that has adaptations to enable it to live in areas where water is in short supply. Any cell containing one complete set of chromosomes. The name of the trophic level to which photosynthetic organisms belong. A process carried out by bacteria that involves the conversion of atmospheric nitrogen into nitrogenous compounds that can be used directly by plants.
2. Biological molecules  →  2.2. Carbohydrates and lipids
1. Cell structure  →  1.2. Cells as the basic units of living organisms
16. Inheritance  →  16.1. Passage of information from parents to offspring
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6
For Examiner’s Use is a section through lung tissue showing an alveolus and its blood supply. X Y A B Name the type of epithelial cell shown by label lines A and B. Describe how the elastic fibres of the alveoli contribute to the healthy functioning of the lungs. The actual diameter of the alveolus along the line X–Y is 220 micrometres (µm). Calculate the magnification of . Show your working and give your answer to the nearest whole number. answer × Outline two features of a gas exchange surface that are shown on . 1. . 2. For Examiner’s Use is a simplified diagram of the circulatory system of a human, showing gas exchange in the lungs and in respiring tissue. The partial pressures of oxygen (pO2) and carbon dioxide (pCO2) at four locations are also shown. branch of pulmonary artery pCO2 6.00 kPa pO2 5.33 kPa pCO2 5.33 kPa pO2 13.87 kPa capillary network (venous end) pCO2 6.00 kPa pO2 5.33 kPa capillary network (arterial end) pCO2 5.33 kPa pO2 13.33 kPa not to scale branch of pulmonary vein alveolus body tissue heart pCO2 5.33 kPa pO2 13.87 kPa
9. Gas exchange  →  9.1. The gas exchange system
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