A technician monitored one species of bacterium growing in nutrient broth for use in an industrial process. The conditions remained suitable and the mean division time remained constant.
| Time after the culture was started in minutes | Number of bacteria |
|---|---|
| 0 | 40 |
| 100 | 640 |
Calculate the mean division time of the bacteria.
The culture can be used when it first contains at least 300 000 bacteria.
Calculate the earliest time after the culture was started that it can be used.
At the time calculated in part (b), the technician transferred one eighth of the bacteria to a second vessel containing sterile nutrient broth.
The technician claimed that the second vessel would contain at least 350 000 bacteria after a further 75 minutes.
Evaluate the technician's claim.
282 exam-style questions on AQA GCSE Biology 1.1 Cell structure, covering 1.1.1 Eukaryotes and prokaryotes, 1.1.2 Animal and plant cells, 1.1.3 Cell specialisation, 1.1.4 Cell differentiation, 1.1.5 Microscopy, and 1.1.6 Culturing microorganisms. Each one has a worked solution and a mark scheme showing where the marks go.