21.2. Biotechnology
A subsection of Biology, 0610, through 21. Biotechnology and genetic modification
Listing 10 of 143 questions
A factory uses biotechnology to process apples. Some of the apple juice is mixed with yeast and used to make ethanol. State the type of respiration in yeast that produces ethanol. State the name of the substance in apple juice that is converted to ethanol by yeast. The yeast uses enzymes to produce ethanol. Define the term enzyme. shows apparatus used to find the best temperature for making ethanol. yeast and apple juice stop-clock bubbles of gas water The same apparatus was used at different temperatures. The rate of ethanol production was compared by counting the number of bubbles of gas produced by the yeast and apple juice mixture per minute. State the name of the gas produced by the yeast in . The results of the investigation are shown in . rate of reaction / bubbles per minute temperature / °C Calculate the increase in the rate of reaction from 20 °C to 25 °C in . Space for working. bubbles per minute State the optimum temperature for the reaction shown in . °C The cut surface of an apple usually turns brown when exposed to air. This is caused by enzymes. Three slices of apple were given different treatments and were then exposed to air for 30 minutes. Table 6.1 shows the treatments and appearance of the apple slices. Table 6.1 apple slice pH temperature / °C appearance of the apple slice at 0 minutes appearance of the apple slice after 30 minutes A white brown B white white C white white Suggest why slice B and slice C did not turn brown after 30 minutes. slice B slice C The enzyme pectinase is used in industry for the production of apple juice. Explain why pectinase is used when making apple juice. Hygienic conditions are required in an apple juice factory. Describe three precautions workers should take to ensure that good food hygiene is maintained in the apple juice factory.
0610_w18_qp_33
THEORY
2018
Paper 3, Variant 3
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Yeast cells have many structures in common with a plant cell. is a drawing of a yeast cell. A B C D cell wall State the names of the cell structures labelled A and D on . A D State the functions of the cell structures labelled B and C on . B C State the name of one structure that is found in plant cells but is absent in yeast cells. Yeast is used in the production of ethanol to manufacture a type of biofuel. is a flow chart of the process. maize plants maltose enzyme S enzyme T process U in anaerobic conditions glucose extraction of starch from maize ethanol carbon dioxide State the names of enzymes S and T. S T Yeast is used in process U. Complete the balanced chemical equation for anaerobic respiration in yeast. C2H5OH + Suggest the advantages of using biofuels instead of fossil fuels. Carbon dioxide may be collected from process U and sold for use in glasshouses. Explain why carbon dioxide is used in glasshouses.
0610_w20_qp_42
THEORY
2020
Paper 4, Variant 2
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Yeast is an example of a single-celled fungus. The population of yeast can be estimated by using a light microscope to view a small sample of yeast cells in a modified microscope slide. There is a square chamber, with a specific volume, cut into the microscope slide and a grid to make it easier to count the number of cells. shows a diagram of the modified microscope slide. It also shows part of a light microscope with the modified microscope slide filled to the top with a sample of yeast cells. grid chamber The length of the sides of each small square in the grid in the modified microscope slide is 200 μm. The depth of the chamber is 100 μm. There is a total of 25 small squares in the grid. Each small square in the grid has an average of 52 yeast cells. Calculate the concentration of yeast cells per mm3. Space for working. cells per mm3 A small sample of yeast cells and 19 g per dm3 of sugar were added to a fermenter. The population size of live yeast cells and the concentration of the sugar in the fermenter were calculated every day for 10 days. The results are shown in and . time / days concentration of sugar / g per dm3 time / days population size of live yeast cells Draw an X on to indicate the position of the lag phase. Complete the line on to show the expected change in the population size of live yeast cells from day 3 to day 10. Describe and explain the changes in the concentration of sugar in the fermenter over the 10-day period. Explain why it is important that there is a tube in the fermenter that allows gases to escape.
0610_w20_qp_43
THEORY
2020
Paper 4, Variant 3
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Humans have developed modern farming methods to increase food production. Explain how the use of herbicides and chemical fertilisers has increased food production. shows intensive farming of chickens. State three disadvantages of intensive livestock production. The protein pectinase is used in food industries to make fruit juice clear. Pectinase is an example of a type of protein. State the name of this type of protein. shows the process used to produce clear fruit juice. 1 Collect and wash whole fruit 2 Crush fruit and collect juice 3 Heat juice to 30 °C 4 Add pectinase and leave at 30 °C for 30 minutes 5 Heat to a high temperature for 20 seconds 6 Filter and bottle fruit juice Explain why a temperature of 30 °C is used in step 4. During step 4 amylase may be added to the fruit juice. Suggest the purpose of adding amylase. Explain why the juice is heated to a high temperature in step 5. Yeast is used in biotechnology. Circle two uses of the products of anaerobic respiration in yeast. biofuels bread‑making herbicide production insulin production lactic acid production washing powders
0610_w23_qp_31
THEORY
2023
Paper 3, Variant 1
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Questions Discovered
143