7.7.6 Biodiversity. 39 minutes. 39 marks. Page 1 of 10

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1 7.7.6 Biodiversity 39 minutes 39 marks Page 1 of 10

2 Q1. The drawings show changes to a farm between 1953 and The fields on the farm are separated by hedges. (i) Give two major changes which were made to the land on this farm between 1953 and (2) (ii) How would these changes affect the number of wild animals which live on the farmland? Explain your answer. (2) (Total 4 marks) Page 2 of 10

3 Q2. The drawings and text for this question are based on an article from The Independent newspaper. Some of Britain s rarest wild flowers are likely to make a come-back thanks to an EC set-aside regime in which 15 per cent of arable land has been taken out of production. As a result of this set-aside, shepherd s needle, pheasant s eye, corn gromwell, corn cockle, spreading hedge parsley and corn mouse tail are now thriving once again. They were once common in and around cereal fields and were even regarded as weeds, but were swept to near extinction by the intensification of agriculture after the Second World War. Their small, pale flowers are hardly seen. These plants cannot compete in fields where modern cereal crops are cultivated. Nor, however, do they flourish in semi-natural or wild habitats where nature is left to its own devices. They need farmland which is lightly tilled and cut once a year. Dr Nick Sotherton, lowland research manager with the Game Conservancy Council, says that these species will flourish under the new rotational set-aside regime, in which farmers are compensated for taking land out of production in an attempt to end crop surpluses. EC agriculture ministers are meeting to decide how much land should be used for rotational setaside in which a field is taken out of production for just one year before being replanted and how much should be set-aside permanently. The ultimate set-aside is a wood, and Britain is seeking a forestry option. The Game Conservancy Council says that the rotational scheme can benefit ground nesting birds as well as rare flowers that will not be helped by longer-term set-aside. But Richard Knight of the Wildlife Advisory Group, says Non-rotational is better because it gives flora and fauna a chance to get well established. Intensification of agriculture has led to the creation of artificial ecosystems. Page 3 of 10

4 (a) Explain how the creation of artificial ecosystems may have led to the near-extinction of the plants seen in the picture above. (4) (b) What would you recommend to ministers meeting to decide a policy involving rotational set-aside and permanent set-aside? Explain the reasons for your answer. (4) (Total 8 marks) Page 4 of 10

5 Q3. The following passage is adapted from an article by Martin Kelly in The Independent newspaper. Thanks to the test tube banana Specially bred resistant varieties may save African crops from disease A banana is a fruit, but it has no seeds. And if there are no seeds how do the plants reproduce? At one level the answer is easy; centuries of selective breeding have resulted in varieties with plenty of tasty flesh but few bitter inedible seeds, and propagation is carried out by means of root corms. Most bananas we eat are thus actually 'clones' of a few successful plants, as is also the case with the potato. Banana clones are genetically identical to their parents, so growers can be completely sure their fruits will be big and tasty. Genetic variability of these cloned plants is extremely low. Resistance to new diseases, therefore, is almost nil; witness the spread of potato blight through Ireland in the 1840s. The issue goes well beyond our high streets and supermarkets. The banana has a larger relative called a plantain, which is starchy rather than sweet and is a staple food of more than 60 million Africans. Bananas and plantains are being ravaged by a new fungal disease called Black Sigatoka. The commercial planters that produce the bananas we buy in supermarkets have little problem here; they can afford to buy chemicals to spray their crops. African subsistence farmers, forced to rely on 'organic' methods can only sit by and watch their plants die. Several governments have turned to the International Institute for Tropical Agriculture (IATA) for help. IATA is in Africa, but is not of Africa. It is internationally funded with levels of staffing and equipment that enable advanced bio-technological techniques to be used. However, even with genetic engineering, to breed resistant varieties is a long-term project and Black Sigatoka is not going to wait. IATA scientists have had to divide their energies between two approaches: an interim solution and the development of resistant varieties. The interim solution was easily found in a group of 'cooking bananas' which were resistant to Black Sigatoka disease and which could, to some extent, be substituted for plantain in the diet. These, however, were only found in localised areas and the first problem facing IATA was to obtain enough plants from the few available plants of resistant varieties to supply the needs of the affected farmers. Page 5 of 10

6 (a) Explain how selective breeding may have been used to produce bananas with tasty flesh. (2) (b) Explain, as fully as you can, why Genetic variability of these cloned plants is extremely low compared with natural populations. (4) (c) Explain, as fully as you can, how IATA scientists might be able to obtain enough plants from the few available plants of resistant varieties to supply the needs of affected farmers. (3) (d) Explain, as fully as you can, how IATA scientists may use genetic engineering to produce varieties of banana resistant to Black Sigatoka disease. (4) (Total 13 marks) Page 6 of 10

7 Q4. The photograph shows an area where a tropical forest is being cleared. (a) Complete the sentences. People could use timber from the forest for.... The cleared land can be used for.... Clearing forests increases the concentration of... in the atmosphere. This increase causes global.... (4) (b) Clearing forests causes some species to become extinct. (i) What is meant by extinct? Page 7 of 10

8 (ii) It is important to prevent species from becoming extinct. Give one reason why. (Total 6 marks) Q5. The drawings show some woodland and some farmland. Both have a river flowing through. (a) (i) There is a wider variety of wildlife in the woodland than in the farmland. Give one reason why. (ii) Farmers remove woodland to provide space for growing crops. Give two other reasons why humans remove woodland. Do not include the uses of wood in your answers (2) (b) Many farmers spray chemicals on their fields. Draw a ring around the correct word to complete each sentence. fertilisers (i) To make crops grow larger, farmers use herbicides. pesticides Page 8 of 10

9 fertilisers (ii) To kill insects that feed on the crop, farmers use herbicides. pesticides (iii) There is a wider variety of wildlife in the river flowing through the woodland than in the river flowing through the farmland. Give one reason why. (c) The population of the UK has increased over the last two hundred years. This increase in population has resulted in damage to the environment. Apart from farming methods, give two ways in which humans damage the environment (2) (Total 8 marks) Page 9 of 10

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