0610_s12_qp_31
A paper of Biology, 0610
Questions:
6
Year:
2012
Paper:
3
Variant:
1
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1
For Examiner's Use is a diagram of the human digestive system. A B C D E F G H J Use the letters from to complete Table 1.1 to give the part of the human digestive system that is identified by each function. Write one letter only in each box. You may use the same letter more than once. There are some letters that you will not use. The first one has been done for you. Table 1.1 function letter peristalsis B protein digestion insulin production deamination partially digested food is mixed with bile most water is reabsorbed For Examiner's Use The human diet provides nutrients for the synthesis of biological molecules that make up cells, cell products and tissues. Complete Table 1.2 to show the nutrients that are absorbed from food to synthesise the large molecules listed. Table 1.2 large molecules nutrients absorbed protein glycogen fat Mineral ions are required in the human diet in small quantities. State the mineral ion required for each process: making bone making haemoglobin. State another type of nutrient required in the human diet in small quantities. For Examiner's Use One role of nutrients is to provide materials for the repair of damaged tissues. shows the events that happen after a cut to the skin. immediately after the cut 24 hours later 3 to 7 days later 2 weeks later epidermis damaged capillary released blood scab blood clot phagocytes new capillary Use the information in to describe what happens to seal the wound in the skin and repair the skin tissue.
7. Human nutrition  →  7.2. Digestive system
7. Human nutrition  →  7.5. Absorption
7. Human nutrition  →  7.3. Physical digestion
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2
For Examiner's Use The Galápagos Islands in the Pacific Ocean have many species of animals and plants that live nowhere else. Iguanas are large herbivorous reptiles. Four species of iguana live on the Galápagos Islands: • marine iguana, Amblyrhynchus cristatus • land iguana, Conolophus subcristatus • Santa Fe land iguana, Conolophus pallidus • pink land iguana, Conolophus rosada shows a marine iguana. Reptiles and mammals are both vertebrates. State three features of mammals that are not found in reptiles. For Examiner's Use The marine iguana, A. cristatus, feeds on seaweed and must therefore dive several metres into the cold waters that surround the Galápagos Islands. Iguanas can only stay in the water for a short length of time, until their body temperature drops too low. Mammals of an equivalent size, such as sea otters, can stay in cold water for a long time. Explain how some mammals are able to stay in cold water for a long time. Land iguanas live on Isabela, the largest island in the Galápagos. In 1986, some rangers from the Galápagos National Park found a population of pink land iguanas living at the northern end of the island. These iguanas have been studied in detail and are now classified as a new species, C. rosada. Define the term population. Suggest how a study of the DNA of iguanas helps to classify them. For Examiner's Use The International Union for the Conservation of Nature describes these iguanas as vulnerable. This means that their populations are likely to become extinct. Suggest two reasons why it is important to conserve individual species, such as the four species of iguana on the Galápagos Islands.
20. Human influences on ecosystems  →  20.4. Conservation
20. Human influences on ecosystems  →  20.2. Habitat destruction
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3
For Examiner's Use In Sichuan, in China, a sauce is made from broad bean seeds that have germinated and then have been left to ferment. shows a germinating broad bean seed. K L M N Name K to N. K L M N Broad beans contain starch. The germinating beans are colonised by yeasts and other fungi, such as Aspergillus. Aspergillus grows over the surface of beans and digests starch. It has a body made of thin threads that secrete enzymes, such as amylase. Name the thin threads that make up the body of a fungus, such as Aspergillus. For Examiner's Use The action of enzymes is often explained in terms of the ‘lock and key’ model as shown in . substrate enzyme Use the information in to explain how enzymes work to break down nutrient materials, such as starch. For Examiner's Use Enzymes in bean seeds are activated during germination. Some of these enzymes break down protein stored in the seeds. A large number of bean seeds were soaked and germinated. Researchers took samples of germinating seeds over a period of 15 days. The seeds were chopped into small pieces and crushed with water to make an extract. Equal quantities of the extracts were placed into protein solutions at pH 5 and at pH 8. The activity of the enzymes in each extract was determined by recording how quickly the protein was broken down. The results are shown in . time / days enzyme activity / arbitrary units pH 8 pH 5 Describe the activity of the enzymes in the extracts at pH 5 over 15 days. For Examiner's Use The researchers concluded that the beans contained two different enzymes that break down protein. State the evidence from for this conclusion.
5. Enzymes  →  5.1. Enzymes
7. Human nutrition  →  7.4. Chemical digestion
4. Biological molecules  →  4.1. Biological molecules
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4
For Examiner's Use is an electron micrograph of some red blood cells and lymphocytes. Lymphocytes respond to infection by making and releasing special protein molecules called antibodies. Describe how antibodies provide protection from diseases caused by viruses and bacteria. For Examiner's Use Red blood cells have special molecules on their cell membranes. These are known as antigens and they stimulate the production of antibodies. These antigens also determine a person’s blood group. Before carrying out kidney transplants, it is important to check that the blood group of the donor matches the blood group of the recipient. This is called blood typing. It is necessary because blood group antigens are present on the inner lining of blood vessels in the kidney. Explain what would happen if a kidney from a person with blood group A was transferred into the body of a person with blood group O. Tissue typing is carried out before transplanting a kidney. This makes sure that there is a close match between the donated kidney and the recipient. However, it is possible to carry out transplants of the cornea without blood typing or tissue typing. Suggest why it is possible to transplant corneas successfully without carrying out any tissue typing or blood typing. For Examiner's Use The gene for the ABO blood group has three alleles, IA, IB and Io. A person with blood group O has parents who have blood groups A and B. Complete the genetic diagram to show how this is possible. Use the symbols, IA, IB and Io, for the blood group alleles. parental phenotypes parental genotypes gametes offspring genotype offspring phenotype blood group B blood group A × × + blood group O Use your answer to to give examples of the following. The first one has been completed for you. term example a dominant allele IA heterozygous genotype ……………………… codominant alleles ……………………… phenotype ………………………
17. Inheritance  →  17.4. Monohybrid inheritance
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5
For Examiner's Use shows the structure of the placenta and parts of the fetal and maternal circulatory systems. V W Y X T Z Complete Table 5.1 by listing the blood vessels that carry oxygenated blood. Use the letters in to identify the blood vessels. Table 5.1 circulatory system blood vessels that carry oxygenated blood maternal fetal Name structure T and describe what happens to it after birth. For Examiner's Use The placenta is adapted for the exchange of substances between the maternal blood and the fetal blood. Describe the exchanges that occur across the placenta to keep the fetus alive and well. The placenta secretes the hormones oestrogen and progesterone. Describe the roles of these hormones during pregnancy.
16. Reproduction  →  16.4. Sexual reproduction in humans
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6
For Examiner's Use In South America, forests have been cut down to provide land for cattle grazing and for growing crops, such as soya beans. shows an area before deforestation and after the planting of soya. Occasionally small areas of forest are left if the land cannot support agriculture. Suggest the disadvantages of removing the forest from all but small areas of land. Much of the soya is used to feed farm animals rather than to make foods that humans can eat. Explain the advantages of using soya as food for humans rather than for farm animals. For Examiner's Use Much of the cleared forest in South America is used as land for cattle grazing. The clearing of forest and keeping large numbers of cattle have severe effects on the environment, especially the atmosphere. Outline the effects of forest clearance and cattle farming on the atmosphere. Yields from crops grown on soils like those in are likely to decrease over time. State reasons for the likely decrease in yields. Forest products are used in the manufacture of paper. Explain the environmental advantages of recycling paper.
20. Human influences on ecosystems  →  20.1. Food supply
21. Biotechnology and genetic modification  →  21.3. Genetic modification
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