A student added one bacterium to a tube of sterile nutrient broth. The tube was incubated at 25 degrees Celsius. At this temperature the mean division time of the bacterium is 20 minutes.
Calculate the number of divisions that take place in 4 hours.
Calculate the number of bacteria present after 4 hours. Give your answer in standard form.
The student repeated the investigation at 30 degrees Celsius. At this temperature the mean division time is 15 minutes.
Calculate how many times greater the number of bacteria is after 4 hours at 30 degrees Celsius than after 4 hours at 25 degrees Celsius.
139 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.