A bacterial pathogen reaches a region where farmers grow two varieties of potato. Variety L is resistant to the pathogen, but variety K is not.
The table shows the area planted with each variety and the mean yield before and after the pathogen arrived.
| Potato variety | Area planted in hectares | Yield before the pathogen arrived in tonnes per hectare | Yield after the pathogen arrived in tonnes per hectare |
|---|---|---|---|
| K | 3600 | 40 | 22 |
| L | 1400 | 34 | 33 |
Calculate the percentage decrease in the total mass of potatoes produced in the region after the pathogen arrived.
Give your answer to 1 decimal place.
Farmers are considering growing more variety L and less variety K.
Explain how this change could make the potato supply more stable from one year to the next.
Scientists find a gene in a bacterium. The gene codes for a protein that stops the potato pathogen growing.
Suggest one reason why genetic engineering could be used, but selective breeding could not be used, to transfer this gene to variety K.
127 exam-style questions on OCR GCSE Biology 6.2 Feeding the human race, covering 6.2.1 Biological factors affecting food security, 6.2.2 Agricultural solutions to growing demand, 6.2.3 Selective breeding, 6.2.4 Genetic engineering, 6.2.5 Steps in genetic engineering, 6.2.6 Benefits and risks of gene technology in agriculture, and 6.2.7 Biotechnological solutions to growing demand. Each one has a worked solution and a mark scheme showing where the marks go.