21.2. Biotechnology
A subsection of Biology, 0610, through 21. Biotechnology and genetic modification
Listing 10 of 143 questions
A scientist measured the mass of carbon dioxide produced by anaerobic respiration in yeast cells for 1200 minutes. shows the results. total mass of carbon dioxide produced / g time / minutes Complete the sentences to describe the results shown in . The yeast cells produced a total of g of carbon dioxide during 1200 minutes. The yeast cells stopped producing carbon dioxide at minutes. The investigation was repeated with boiled yeast cells. Predict the effect on the mass of carbon dioxide produced and explain your prediction. State the name of one other product of anaerobic respiration in yeast cells. The box on the left contains the term ‘Respiration’. The boxes on the right contain sentence endings. Draw two lines to join the term ‘Respiration’ to two boxes on the right to make two correct sentences. always produces carbon dioxide. is necessary for diffusion. Respiration occurs only in animals. releases energy. uses glucose. State one substance required for aerobic respiration that is not required for anaerobic respiration. Respiration is one of the characteristics of living things. Tick (3) two boxes to show two other characteristics of all living things. breathing excretion growth photosynthesis sexual reproduction
0610_s22_qp_31
THEORY
2022
Paper 3, Variant 1
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Fungal cells and plant cells contain mitochondria. State the function of mitochondria. State one feature of plants that is used to distinguish them from fungi. Yeast is a fungus that can respire to produce ethanol. State the balanced chemical equation for this type of respiration in yeast. A scientist investigated the effect of sugar on respiration in yeast cells. One flask contained 100 cm3 of a sugar solution and another flask contained 100 cm3 of water. Both flasks contained the same mass of yeast. The temperature was maintained at 25 °C. The scientist used the apparatus shown in . syringe to collect the gas produced oil layer yeast in a sugar solution or yeast in water water bath at 25 °C thermometer is a graph of the results of the investigation. time / minutes volume of carbon dioxide gas produced / cm3 yeast in a sugar solution at 25 °C Key yeast in water at 25 °C Using the gradient shown in , calculate the rate of carbon dioxide gas produced by the yeast in a sugar solution between 10 minutes and 15 minutes. Include the unit. Space for working. Suggest the reason for the oil layer in the apparatus shown in . , , State one reason why no more carbon dioxide gas was produced after 35 minutes by the yeast in a sugar solution, shown in . The scientist repeated the investigation using yeast and the sugar solution at a temperature of 95 °C. Explain why no carbon dioxide was produced at a temperature of 95 °C. State one way in which humans use the carbon dioxide gas produced by yeast cells. State the name of one gas, other than carbon dioxide, that contributes to the enhanced greenhouse effect. , ,
0610_s24_qp_42
THEORY
2024
Paper 4, Variant 2
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For Examiner's Use In the box, state the word equation for aerobic respiration. Complete Table 5.1 to show three differences between aerobic respiration and anaerobic respiration in humans. Table 5.1 aerobic respiration in humans anaerobic respiration in humans ………………………………………… …………………………………………. ………………………………………… …………………………………………. ………………………………………… …………………………………………. ………………………………………… …………………………………………. ………………………………………… …………………………………………. ………………………………………… …………………………………………. For Examiner's Use Yeast is used in making some types of bread and in brewing. Explain the role of yeast in bread making. Explain the role of yeast in brewing.
0610_w10_qp_21
THEORY
2010
Paper 2, Variant 1
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For Examiner's Use A small quantity of a fungus was put into a fermenter with all the nutrients required for growth and kept at an appropriate temperature. The fungus was provided with nutrients at a suitable pH at the start. shows the growth of the fungus over 160 hours. time / hours 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 biomass of fungus / g dm–3 of medium Explain why the biomass of the fungus did not increase during the stationary phase after 110 hours. For Examiner's Use Mycoprotein is a food made from the fungus, Fusarium venenatum. The production process for mycoprotein is shown in . glucose cold water in heat exchanger ammonia and air carbon dioxide filtrate mycoprotein downstream processing fermenter Explain why ammonia and air are pumped into the fermenter. For Examiner's Use The growth depends on the activity of enzymes in the fungus. Explain why the temperature in the fermenter is kept constant. Efficient production of mycoprotein depends on keeping the fungus in the exponential phase of growth. Explain how the production process, shown in , keeps the fungus in the exponential phase. For Examiner's Use The fungus extracted from the fermenter contains nutrients and is converted into foods, such as burgers and sausages, that are suitable for vegetarians. During processing, food additives are mixed with the fungus. State two reasons for mixing food additives with the fungus that is made into foods.
0610_w11_qp_33
THEORY
2011
Paper 3, Variant 3
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Questions Discovered
143