The effects of antibiotics on bacterial growth

Question 1

Briefly outline the steps to set up an agar plate containing bacteria

Answer 1

1) Disinfect area
2) Label agar plate
3) Use pipette to collect culture, FLAME culture bottle
4) Pipette culture into agar plate and close lid
5) Dip glass spreader in ethanol and flame it
6) Use glass spreader to evenly spread the culture
7) Sterilise forceps and take a disc of antibiotic
8) Place disc in A. Repeat
9) In area D, place a sterile filter paper disc that has been soaked in distilled water
10) Tape lid to plate
11) Disinfect area + incubate plate

Question 2

What does the filter paper disc soaked in distilled water act as?

Answer 2

Control

Compare the effectiveness of antibiotics

Question 3

Why do we work near a flaming Bunsen?

Answer 3

To kill bacteria in the air

To sterilise equipment

Question 4

Why do we only slightly lift the lid of the agar plate?

Answer 4

To prevent air containing bacteria from entering

Question 5

Why don’t we completely seal the agar plate?

Answer 5

To allow oxygen to enter, enabling aerobic respiration to take place