1. S CIENCE EXPERIMENT ---------------------------------- Bacteria growth in the various parts of the house

2. T HE PLAN FOR THE EXPERIMENT Materials : measuring instrument to an accuracy to of 0.1cm3 & can measure from 0.1 - 100cm3 at least, cotton swabs, Petri dish, thermometer Materials to make Agar nutrients: agar powder 1.5g, Bovril 2g, sodium chloride 0.5g, water 10cm3 Step 1: mix all the materials to make agar nutrients (agar powder 1.5g, Bovril 2g, sodium chloride 0.5g, water 10cm3) into a paste then slowly add water with stirring until the mixture reaches to 100cm3.

3. T HE PLAN FOR THE EXPERIMENT Step 2: Heat the mixture in a boiling water bath to 95 °C in the required container. Step 3: pour the mixture evenly into six petri dishes evenly.

4. P REPARATION PICTURES Nutrient agar in petri dishesPetri dishes put in ziploc and numbered Mixing the materials together Heating the mixture to required temperature

5. D AY 1 9/12 No difference

6. D AY 2 10/12 No difference

7. D AY 3 11/12 Piano keys: nothing Door knobs: nothing Dining table: bacteria growth starts Hand phone: nothing Computer keyboard: nothing TV button: nothing

8. D AY 3 PICTURES Petri dish no. 3 Overall pictures of petri dishes

9. D AY 4 12/12 Piano keys: growth starts -1 st Door knobs: growth starts -3 rd Dining table: bacteria growth continues -2 nd Hand phone: nothing -6 th Computer keyboard: a bit of bacteria growth noticeable - TV button: a bit of bacteria growth noticeable

10. D AY 4 PICTURES Overall shot of the Petri dishes Petri dish 1Petri dish 2Petri dish 3 Petri dish 4 Petri dish 5 Petri dish 6

11. D AY 5 13/12 Piano keys: most amount of bacteria growth -1 st Door knobs: 4 th Dining table: 2 nd Hand phone: growth starts -6 th Computer keyboard: 5 th TV button: 3 rd

12. D AY 5 PICTURES Petri dish 1 Petri dish 2 Petri dish 3 Petri dish 4 Petri dish 5 Petri dish 6 Petri dish overall shot

13. D AY 6 14/12 Piano keys: most amount of bacteria growth -1 st Door knobs: least amount of bacteria growth noticeable -6 th Dining table: -3 rd Hand phone: -4 th Computer keyboard: -5 th TV button: -2 nd

14. D AY 6 PICTURES Petri dish 1Petri dish 2Petri dish 3 Petri dish 4Petri dish 5 Petri dish 6 Petri dish overall

15. D AY 7 15/12 Piano keys: most amount of bacteria growth -1 st Door knobs: -4 th Dining table: bacteria growth starts -5 th Hand phone: nothing -6 th Computer keyboard: -3 rd TV button: -2 nd

16. D AY 7 PICTURES Petri dish 1 Petri dish 2 Petri dish 3 Petri dish 4Petri dish 5Petri dish 6

17. C ONCLUSION The dirtiest parts of our house is the piano followed by the tv button, then the computer keyboard followed by the door knob, then the dining table and lastly the handphone.