Core Practical: Investigating antibiotics & antiseptics (Edexcel GCSE Biology): Quizzes
📚Quizzes
Practise the questions
11 questions from this quiz
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Practise the questions
11 questions from this quiz
How must glass Petri dishes and agar gel be sterilised before use?
How must glass Petri dishes and agar gel be sterilised before use?
In an autoclave
Why is sterilisation of equipment necessary in this experiment?
Why is sterilisation of equipment necessary in this experiment?
To prevent unwanted bacterial contamination
What is the purpose of the agar in the Petri dishes?
What is the purpose of the agar in the Petri dishes?
Provides nutrient-rich environment for growth
Why is the bacterial solution spread evenly across the agar surface?
Why is the bacterial solution spread evenly across the agar surface?
To ensure a uniform lawn of bacteria
Why are plates only partially sealed with tape, not fully sealed?
Why are plates only partially sealed with tape, not fully sealed?
Allows oxygen in to prevent anaerobic growth
Why are the Petri dishes stored upside down after preparation?
Why are the Petri dishes stored upside down after preparation?
To stop condensation contaminating culture
What is the maximum incubation temperature used in schools?
What is the maximum incubation temperature used in schools?
25°C
At what temperature may medical settings incubate plates?
At what temperature may medical settings incubate plates?
37°C for faster bacterial growth
What is the zone of inhibition?
What is the zone of inhibition?
Clear area where bacteria can't grow
What does a larger zone of inhibition indicate?
What does a larger zone of inhibition indicate?
A more effective antimicrobial agent
What is the purpose of including a control disk in the experiment?
What is the purpose of including a control disk in the experiment?
To ensure accurate comparisons