A biotechnology group is preparing bacteria to produce a protein normally found in cow's milk in a fermenter. The bacteria are mixed with plasmids carrying the gene for this protein and a gene for resistance to antibiotic R. After heat shock, the mixture contains bacteria with a plasmid and bacteria without a plasmid. Which procedure will select the bacteria carrying a plasmid?
Spread the mixture on agar containing antibiotic R and retain colonies that grow.
Spread the mixture on agar without any antibiotic and retain colonies that grow.
Spread the mixture on agar containing a different antibiotic and retain colonies that grow.
Spread the mixture on agar containing the milk protein and retain colonies that grow.
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.