OCR A Level Biology A Level Learner Resource 3



Learner Resource 3 –

Cloning and Biotechnology

Plant and animal cloning question sheet

PRACTICE QUESTIONS

(a) Potatoes are rarely grown from seed. The usual method is to save some of the harvested potatoes and to re-plant them in the spring.

(i) List two advantages of growing potatoes in this way.

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[2]

(ii) In 1845 a new strain of potato blight disease reached Ireland, where potatoes were the staple food of most of the human population. The main variety grown was called the Lumper potato and each year’s crop was grown from a proportion of the previous year’s crop. The disease caused widespread destruction of the potato plants and crop from 1845-1850.

Suggest why the disease quickly destroyed most of the potato crop.

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(iii) Describe the method by which a potato with better resistance to potato blight disease could have been produced in 1850.

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(b) New stocks of plants can be produced today that are certified free of any disease. Describe a modern method for producing a large number of disease-free plants.

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(c) Modern techniques also allow the production of large numbers of genetically identical animals. Explain how a sheep selected for its good characteristics can be used to make more sheep with exactly the same genes and characteristics.

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[Total:15]

OCR past exam questions on this topic can be found at:

F215 June 2011 Q.3 (Dutch Elm disease and tissue culture)



F215 June 2012 Q.3 (Cloning transgenic goats)



F215 June 2014 Q.1 (Gurdon’s toad cloning experiment and developments in animal cloning)



Answer guide

|(a) |(i) |Any 2 from: |2 |

| | |quick ( | |

| | |uniform growth of crop ( | |

| | |all potatoes have same good flavour or texture ( | |

| | | | |

| |(ii) |Any 2 from: |2 |

| | |all the potato plants were, same variety / Lumper /genetically identical ( | |

| | |all were susceptible to the new disease ORA none were resistant to it ( | |

| | |potato crop formed a monoculture this made it easy for the disease to spread ( | |

| | | | |

| |(iii) |Any 3 from: |3 |

| | |selective breeding / artificial selection ( | |

| | |select any potato tubers or plants that are exposed to the disease but not damaged by it ( | |

| | |cross these plants together / cross-pollinate them ( | |

| | |repeat over generations OWTTE ( | |

| | | | |

|(b) | |Any 4 from: |4 |

| | |tissue culture ( | |

| | |using the apical buds / apical meristems ( | |

| | |sterilise, several / many, explants ( | |

| | |grow on nutrient medium with correct proportion of plant growth regulators ( | |

| | |subdivide callus to make more plants ( | |

| | |transfer to rooting and shooting media / grow on in sterile soil ( | |

| | | | |

|(c) | |Any 4 from: |4 |

| | |adult cell cloning / somatic cell nuclear transfer (SCNT) ( | |

| | |remove nucleus from a donor egg ( | |

| | |extract nucleus from a cell from the animal to be cloned ( | |

| | |fuse with empty egg cell using electric shock ( | |

| | |grow on and split embryo into several cells, to make several new embryos ( | |

| | |place these in surrogate mothers to develop ( | |

| | |Total |15 |

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