One bacterium was added to a tube of nutrient broth. The bacterium has a mean division time of 30 minutes.
The table shows the number of bacteria in the tube during the first 2 hours.
Table: The number of bacteria in the tube over 120 minutes
| Time / minutes | Number of bacteria |
|---|---|
| 0 | 1 |
| 30 | 2 |
| 60 | 4 |
| 90 | 8 |
| 120 | 16 |
Use the table. Give the number of bacteria in the tube after 90 minutes.
Give the number of divisions that take place in 2 hours.
The number of bacteria in the tube can be found using the equation below.
number of bacteria = starting number ×2n\times 2^n×2n , where n is the number of divisions
After 10 divisions the tube contains 1024 bacteria.
Write 1024 in standard form.
Give one condition the bacteria in the tube need in order to keep dividing.
163 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.