Take note of how long it takes for the yeast to bubble up and how vigorous the reaction is. Take photos.
Dump another packet of bakers’ yeast onto a plate. Microwave for five seconds.
Mix this yeast into another bowl of warm water. Repeat Step 8.
Repeat steps 9 and 10 for the other packets of yeast, except microwave one sample for fifteen seconds and the other for thirty seconds.
Wearing gloves, use the sterilized swab to collect a sample of bacteria and swab it on a prepared Petri dish. Good places to find bacteria are areas where lots of people touch something, like doorknobs or faucets. Seal the dish and label it “control.” Put it in a warm, dark place. This is your control sample.
Swab another sample from the exact location as the control sample. Smear it on another Petri dish. Seal and label the dish. Place it in a warm, dark place.
Repeat Step 13 for the other two samples.
Let the samples alone overnight.
Take one sample out (not the control) and microwave it for five seconds. Place it back in the warm, dark place.
Repeat Step 16 for the other two samples, except microwave one for fifteen seconds and the other for thirty seconds.
After another day, take out all the samples. Note how many colonies of bacteria are growing and their size.
Analyze all this data. Does microwave radiation affect all life equally? Does time matter? How does each type of organism respond to the radiation?
Terms/Concepts: Microwaves, microbiology, radiation