Year 12 Biology

The Year 12 Biology students have now completed all internal assessment tasks and are preparing for their external exam next term. We conducted their last practical experiment in class earlier this week to finish off the unit. They are currently looking at infectious diseases and how they are treated and controlled. On Monday they created bacterial lawns on agar plates using an e.coli broth and then placed antibiotic mastrings and filter paper dipped in household products with antimicrobial properties on top of the bacterial lawns. Each of the agar plates were placed in the incubator for two days and we then analysed the results on Wednesday. Some of the antibiotics and some of the household products showed zones of inhibition around them, which meant that the antimicrobial effectively killed the e.coli. We discovered that tee tree oil and eucalyptus oil are effective household antimicrobials for e.coli.