A scientist estimated that a sample of nutrient broth contained 2.0 × 104 bacteria per cm3\text{cm}^3cm3 . The flask contained 250 cm3 of broth.
Calculate the total number of bacteria in the flask. Give your answer in standard form.
The mean division time of the bacteria in the flask is 30 minutes.
Calculate the total number of bacteria in the flask 2 hours later. Give your answer in standard form.
The scientist found the value of 2.0 × 104 bacteria per cm3\text{cm}^3cm3 by counting the bacteria in one 0.1 cm3 sample of the broth.
Suggest one reason why the total number of bacteria calculated in part (a) may not be accurate.
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.