A student uses a metal inoculating loop to transfer bacterium A to sterile nutrient agar in one Petri dish. The student then uses the same loop, without heating it again, to transfer bacterium B to sterile nutrient agar in a second Petri dish.
Explain how using the loop in this way could affect the results from the second Petri dish.
87 exam-style questions on Edexcel GCSE Biology 5.3 Immune system and medicines, covering 5.3.1 The specific immune system, 5.3.2 Response to immunisation, 5.3.3 Advantages and disadvantages of immunisation, 5.3.4 Antibiotics and bacterial infections, 5.3.5 Aseptic techniques in culturing, 5.3.6 Cross-sectional areas of cultures, 5.3.7 Stages of developing new medicines, and 5.3.8 Production of monoclonal antibodies. Each one has a worked solution and a mark scheme showing where the marks go.