A plasmid contains a gene that codes for an animal protein and a marker gene for resistance to antibiotic V.
Bacteria were mixed with this plasmid and given a heat shock. Four bacterial cultures, P, Q, R and S, were then each grown from a different single colony of these bacteria. A technician added 1,000,000 living cells from each culture to separate flasks of nutrient broth. The flasks were kept under the same warm conditions for one hour.
| Culture | Antibiotic added to the broth | Number of living cells after one hour |
|---|---|---|
| P | antibiotic V | 90,000 |
| Q | antibiotic V | 7,600,000 |
| R | no antibiotic | 8,200,000 |
| S | antibiotic W | 7,900,000 |
Which culture is shown to contain bacteria carrying the gene for the animal protein?
Culture R, because its population increased without an antibiotic present.
Culture Q, because its population increased while antibiotic V was present.
Culture P, because antibiotic V reduced the number of living cells.
Culture S, because its population increased while antibiotic W was present.
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.