Core prac 15

Question 1

Give the control variables for this practical

Answer 1

• species and amount of bacteria
• temperature and time of incubation
• concentration of antibiotic
• volume of antibiotic and size of disc
• pH of agar

Question 2

Explain how incubation conditions would need to be altered if you are attempting to grow pathogenic bacteria vs non-pathogenic bacteria

Answer 2

Non-pathogenic - 25 degrees incubation, neutral/basic pH and free airflow
Pathogenic - 37 degrees incubation,
neutral/acidic pH and no free airflow (grow for longer)