Effect Of Gralic And Mint On Bacteria Growth

Question 1

Controlled variables: 4things

Answer 1

Concentration of plant material, Lawn of bacteria on petri dish, Contamination of petri dish by other microorganisms, same volume of plant material on each disc

Question 2

Other equipment 9 things

Answer 2

Agar plate seeded with bacteria, plant material, industrial denatured alcohol, sterile pipette, paper discs, sterile petri dish, sterile forceps, hazard tape, marker pen

Question 3

Method 8steps

Answer 3

1. Make plant extracts, by crushing plant material with industrial denatured alcohol shake occasionally
2. Pipette extract into sterile paper disc and allow to dry on sterile petri dish
3. Label agar plates, split into 4 section
4. Place 1 disc of each extract in each quadrant of the agar plate close and tape with hazard tape
5. Leave to incubate over night and observe zone of inhibition
6. Carry out controls with just distilled water on discs

Question 4

Possible evaluations 5things

Answer 4

Growth of unwanted bacteria on agar plates, not shaking extract enough to ensure enough active ingredient,
Inconsistency when adding plant extract to paper disc, contaminating controls, using wrong species of bacteria for lawn

Question 5

Independent and dependent

Answer 5

Independent: presence of garlic or mint
Dependent: zone of inhibition around disc