A student passes an inoculating loop through a Bunsen flame until it glows red, then waits before touching the agar with it. Why does the student wait?
So that the hot loop does not melt the plastic lid of the Petri dish above it
So that microorganisms in the air have time to settle away from the agar
So that the metal of the loop has time to become sterile all the way through
So that the hot loop does not kill the bacteria being transferred to the agar
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.