11. Method
1. Boil two potatoes for 20 minutes to destroy any microorganisms present on the skin of the potatoes.
2. While the potatoes are boiling get 4 sterilized containers and using a permanent marker label them A, B, C and D respectively.
3. Containers A and B will be in favorable conditions and containers C and D will be in unfavorable conditions.
4. Container A and C will be your control groups and containers B and D will be your experiment groups.
5. Fill containers C and D with 15 ml of vinegar using a measuring jug.
6. Once the potatoes are finished boiling remove the potatoes with a spoon or tongs and place it on a clean/sterilized chopping board.
7. One potato will be your clean potato and the other potato will be your dirty potato.
8.
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Using a clean/sterilized knife cut the potatoes in half so that you end up with 4 potato halves.
9. Place the one half of the clean potato in container A and the other half of the clean potato in container C, using tongs or a spoon to prevent contamination, and seal the containers.
10. Once the other potato halves have cooled (dirty potato), expose the potato halves to the environment by rubbing it around your hands and along surfaces such as the floor, the kitchen counter or the sink. ( note: they must be exposed to the same surfaces)
11. Place one half of the dirty potato into container B and the other half of the dirty potato into container D. These are your experiment groups.
12. Observe the growth of the bacteria on the potato.
13. Record your observations in a table and record your findings.
12. Precautions
1. Be cautious when dealing with flames or the stove during the boiling of the water. (ask an adult for help if you are not confident)
2. Use tongs or a spoon to remove the boiled potato to prevent contamination (transfer of germs/ bacteria that could impact the experiment results).
3. Be cautious when using a knife to cut the potatoes in half. (ask an adult for help if you are not