Q26

Criteria	Marks
Provides a logical procedure to test the effectiveness of Jelly Bush honey as an inhibitor of bacterial growth; provides independent variable, dependent variable, variables kept constant and the use of a control; includes appropriate safety considerations; includes repetition	5
Provides a logical procedure to test the effectiveness of Jelly Bush honey as an inhibitor of bacterial growth; provides most of the features of a safe valid investigation such as independent variable, dependent variable, variables kept constant and the use of control; includes repetition	4
Provides a procedure to test the effectiveness of Jelly Bush honey as an inhibitor of bacterial growth; provides some features of a valid investigation	3
Provides some features of a relevant investigation	2
Provides some relevant information	1

Sample answer:

1. Select appropriate safety equipment including gloves and safety clothing.
2. Prepare three nutrient agar plates, using sterile techniques. Seal one plate and label as control.
3. Inoculate the remaining plates with bacteria to cover the agar surface.
4. Place a sterile paper disc soaked in distilled water in the middle of an agar plate. Seal and label as Water.
5. Place a sterile paper disc soaked in Jelly Bush honey in the middle of an agar plate. Seal and label as Honey.
6. Incubate the plates at 25°C for 48 hours.
7. Remove from incubator but do not open any of the plates after incubation.
8. Observe the control plate to check for any contaminating bacteria.
9. For each agar plate, measure the zone of inhibition from edge to edge.
10. Repeat the experiment three more times and calculate an average.

Answers could include:

• Direct application of honey
• Incorporation of honey into agar plates
• Concentration of methylglyoxal.