0610_s10_qp_31
A paper of Biology, 0610
Questions:
6
Year:
2010
Paper:
3
Variant:
1
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1
For Examiner's Use Define the term sensitivity. shows a horizontal section through the eye. X Y A B C D E Name structures A to D. A B C D State the functions of structures B and E. B E For Examiner's Use The retina contains light-sensitive cells known as rods and cones. The distribution of rods in the retina from point X to point Y, as shown on , was investigated. shows the distribution of rods in the retina from point X to point Y. number of light- sensitive cells X G H Y distance along the retina G and H, as shown on , are parts of the retina. Name G and H. G H Describe the function of the rods. Draw a line on to show the distribution of cones in the retina.
14. Coordination and response  →  14.2. Sense organs
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2
For Examiner's Use A student measured the uptake and release of carbon dioxide from a plant during 24 hours. It was a very bright, sunny day between sunrise and sunset. shows the student’s results. time / h uptake of carbon dioxide release of carbon dioxide no net uptake or release Use the information in to state the time that sunrise occurred. Using , state the times when there is no uptake or release of carbon dioxide. 1. 2. State why plants release carbon dioxide at night. Explain why it is important for plants that carbon dioxide uptake during the day is greater than carbon dioxide released at night. For Examiner's Use The yields of tomatoes grown in open fields in India are very low compared with yields of tomatoes grown in glasshouses in Europe. In a study, scientists in India grew tomato plants in glasshouses and in open fields nearby. The growth of the plants and the yields of tomatoes were recorded. The results are shown in Table 2.1. Table 2.1 tomato plants grown in glasshouses open fields mean final height of tomato plants / cm 84.1 69.0 mean number of leaves per tomato plant 123.0 82.0 mean fresh mass of tomato plants / g 988.3 491.7 mass of tomatoes per plant / g 2986.0 818.9 mean fresh mass of tomatoes / g 95.0 84.4 The mean fresh mass of tomatoes grown in glasshouses was greater than the mean fresh mass of tomatoes grown in open fields. Calculate the difference in mean fresh mass as a percentage of the mean fresh mass of tomatoes grown in open fields. Show your working. Answer = % For Examiner's Use Suggest how an increase in the height of the plants and the number of leaves on each plant affects the yield of tomatoes. The scientists made sure that the only differences between the two groups of plants were the result of the protection provided by the glasshouses. Suggest the factors that the scientists should have kept the same for the two groups of plants in this investigation. The growth and final yields of crops grown in open fields are often limited by environmental factors. Describe how these factors are controlled in commercial glasshouses to give high yields of crops such as tomatoes.
6. Plant nutrition  →  6.1. Photosynthesis
20. Human influences on ecosystems  →  20.1. Food supply
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For Examiner's Use shows a human egg cell and a human sperm cell. 10 µm human sperm cell human egg cell 100 µm What is the name given to the release of eggs from the ovary? Sperm cells and egg cells are haploid. State the meaning of the term haploid. For Examiner's Use Complete the table to compare egg cells with sperm cells. feature egg cells sperm cells site of production relative size numbers produced mobility Three hormones that control the menstrual cycle are: • follicle stimulating hormone (FSH) • luteinising hormone (LH) • oestrogen. Name the site of production and release of oestrogen. Describe the role of oestrogen in controlling the menstrual cycle. Artificial insemination is sometimes used as a treatment for female infertility. Outline how artificial insemination is carried out in humans.
16. Reproduction  →  16.4. Sexual reproduction in humans
16. Reproduction  →  16.5. Sex hormones in humans
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4
For Examiner's Use Acid rain is a serious environmental problem in some areas of the world. Lakes in Canada, Norway and Scotland are highly acidic as a result of acid rain. shows a cause of acid rain. power stations and factories release sulfur dioxide rain becomes acidic harming vegetation and organisms that live in water wind-blown chemicals combine with water vapour in the air lake State one cause of acid rain other than that shown in . Describe two effects of acid rain on forest ecosystems. 1. 2. Describe two different ways to reduce pollution so that there is less acid rain. 1. 2. For Examiner's Use shows the pH ranges that some animals that live in lakes can tolerate. trout bass perch frogs salamanders clams snails crayfish mayfly larvae blackfly larvae fish amphibians molluscs crustacean insects group examples 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 animals pH State one feature of molluscs that is not a feature of crustaceans. Using the information in , name an animal that could be found in a lake with a pH of 4.0; name the animals that are most sensitive to a decrease in pH; suggest why some animals cannot tolerate living in water of pH as low as 4.0.
20. Human influences on ecosystems  →  20.3. Pollution
20. Human influences on ecosystems  →  20.2. Habitat destruction
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5
For Examiner's Use shows the processes involved in the manufacture of yoghurt. milk milk heat treated at 85–95 °C for 15 to 30 minutes milk homogenised to give an even consistency starter culture of bacteria added mixture incubated at 37– 44 °C mixture cooled yoghurt is packed and sent at 4 °C to shops sugar may be added food additives and fruit added milk cooled oxygen used up pH decreases Explain why the milk must be cooled before the bacteria are added. Explain why the pH decreases only after the oxygen in the milk has been used up. Suggest one type of food additive that could be added to yoghurt. For Examiner's Use The starter culture contains two species of bacteria, Streptococcus thermophilus and Lactobacillus bulgaricus. shows the growth of these bacteria during the production of yoghurt. time since start of incubation / h numbers of bacteria S. thermophilus L. bulgaricus Using your knowledge of population growth and the factors that affect it, describe and explain the growth of S. thermophilus, as shown in . For Examiner's Use Suggest why the numbers of L. bulgaricus do not start to increase until after the increase in the numbers of S. thermophilus.
21. Biotechnology and genetic modification  →  21.2. Biotechnology
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6
For Examiner's Use The Food and Agriculture Organization (FAO) collects data on food supplies worldwide. The FAO classifies the causes of severe food shortages as either by natural disasters or as the result of human action. Natural disasters are divided into those that occur suddenly and those that take a long time to develop. Human actions are divided into those that are caused by economic factors and those that are caused by wars and other conflicts. shows the changes in the number of severe food shortages between 1981 and 2007. 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 total natural disasters result of human action year number of severe food shortages For Examiner's Use shows the causes of severe food shortages in the 1980s, 1990s and 2000s. natural disasters result of human action key sudden onset economic factors slow onset war and conflict 1980s 1990s 2000s 86 % 80 % 73 % 14 % 20 % 27 % 14 % 2 % 20 % 27 % 11 % 98 % 89 % 73 % 27 % 11 % 27 % 98 % 89 % 73 % State two types of natural disaster that occur suddenly and may lead to severe food shortages. 1. 2. State one type of natural disaster that may take several years to develop. For Examiner's Use Use the information in and to describe the changes in food shortages between 1981 and 2007. Explain how the increase in the human population may contribute to severe food shortages. For Examiner's Use The quality and quantity of food available worldwide has been improved by artificial selection (selective breeding) and genetic engineering. Use a named example to outline how artificial selection is used to improve the quantity or quality of food. Define the term genetic engineering.
20. Human influences on ecosystems  →  20.1. Food supply
19. Organisms and their environment  →  19.2. Food chains and food webs
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