A student is sterilising an inoculating loop before using it to transfer bacteria to a sterile agar plate.
Why is the loop heated in the flame until it glows red, and then allowed to cool before transferring the bacteria?
To sterilise the loop by killing any unwanted microorganisms, and to prevent killing the bacteria being transferred.
To melt a channel in the agar for the bacteria, and to prevent the loop from bending.
To attract bacteria to the loop using heat, and to keep the agar from cracking.
To encourage rapid bacterial cell division, and to prevent the loop from rusting.
44 exam-style questions on OCR GCSE Biology Practical skills. Each one has a worked solution and a mark scheme showing where the marks go.