A student wants to grow bacteria collected from a classroom door handle as separate colonies.
The student writes this method.
| Step | Method |
|---|---|
| 1 | Pour nutrient broth into a Petri dish that has been washed with water. |
| 2 | Take an inoculating loop directly from the equipment drawer and use it to transfer the sample. |
| 3 | Remove the lid completely and leave the culture uncovered for several minutes while transferring the sample. |
Each step contains at least one error.
Give one change to the type of culture medium in step 1 and one change to how the Petri dish and culture medium are prepared.
Describe how the inoculating loop should be prepared before it touches the sample.
State two changes to the way the lid is handled in step 3.
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.