Zoe is investigating the effectiveness of different antiseptics on the growth of E. coli bacterium.She is testing three antiseptics at 5% concentration.This is part of Zoe's method:8. Using sterilised forceps, dip a paper disc in antiseptic one (figure 1).9. Shake off any excess liquid.10. Lift the lid of the agar plate slightly, then place the paper disc down in the relevant section of the agar plate (figure 2).11. Repeat steps 8 to 10 with the other two antiseptics, using a new pair of sterilised forceps each time.How could Zoe improve the accuracy of this part of the method, to ensure each disc has the same amount of antiseptic on it?Choose from the following.Dip a fourth disc in another disinfectant, so four are tested at the same time.Shake the discs for a set amount of time.Only dip half of each disc in the disinfectants.Use sterilised pipettes to place a set number of drops of the disinfectants on each paper disc.I DON'T KNOWSUBMIT ANSWERLearning MaterialChoose your materialCENTURY ExplainsSlideshowAim & BackgroundVariablesEquipment IEquipment IIAutoclave & IncubatorSafetyResults TableCalculator FunctionMethod: Clean the Work SurfaceMethod: Bunsen BurnerMethod: Agar Plate LabelsMethod: ControlMethod: Disc 1Method: Disc LocationMethod: Control DiscMethod: Seal with TapeAnalysis: Zone of InhibitionAnalysis: Mean Zone MeasurementsAnalysis: Calculate Mean Cross-sectional AreaConclusionAlternative Method IAlternative Method IIQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionSummary

Kaya is investigating the effectiveness of different antiseptics on the growth of E. coli bacterium.The are testing three antiseptics at 50% concentration.This is part of Kaya's method:8. Using sterilised forceps, dip a paper disc in antiseptic one (figure 1).9. Shake off any excess liquid.10. Lift the lid of the agar plate slightly, then place the paper disc down in the relevant section of the agar plate (figure 2).11. Repeat steps 8 to 10 with the other two antiseptics, using a new pair of sterilised forceps each time.How could Kaya improve the accuracy of this part of the method, to ensure each disc had the same amount of antiseptic on it?Choose from the following.Use sterilised pipettes to place a set number of drops of the disinfectants on each paper disc.Make sure the antiseptics are all the same concentration.Dip a fourth disc in another disinfectant, so four are tested at the same time.Make sure the antiseptics are creams, and not liquids.I DON'T KNOWSUBMIT ANSWER

The images below show the main steps involved when investigating the effect of antiseptics on the growth of bacteria.Place the images in the correct order.Step 1Step 2Step 3Step 4Step 5Step 6Possible AnswersI DON'T KNOWRESETSUBMIT ANSWERLearning MaterialChoose your materialCENTURY ExplainsSlideshowAim & BackgroundVariablesEquipment IEquipment IIAutoclave & IncubatorSafetyResults TableCalculator FunctionMethod: Clean the Work SurfaceMethod: Bunsen BurnerMethod: Agar Plate LabelsMethod: ControlMethod: Disc 1Method: Disc LocationMethod: Control DiscMethod: Seal with TapeAnalysis: Zone of InhibitionAnalysis: Mean Zone MeasurementsAnalysis: Calculate Mean Cross-sectional AreaConclusionAlternative Method IAlternative Method IIQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionQuestionSummary

When investigating the effect of different types of antiseptic on the growth of bacteria, one paper disc is dipped in distilled water and placed on the agar plate, along with discs that have been dipped in the antiseptics.We call the disc dipped in distilled water a control. This is different to a control variable.Match the answers to the sentence starters to explain what a control is and why it is needed.A control is set up to prove that the results obtained are due to changes in the...This means that the control test must be set up......but...For this experiment, the paper disc dipped in distilled water must be set up...The distilled water should have......helping to prove that changes seen around the other disc are due to...Possible Answers...no effect on the growth of bacteria......in exactly the same way as other tests......a significant effect on the growth of bacteria......on the same agar plate as the discs dipped in the antiseptics so that it is exposed to exactly the same conditions....without the independent variable....in an entirely different way to the other tests......independent variable only, and not due to changes in any other variable or condition....the bacteria only, and not due to changes in any other variable or condition....the antiseptics only, and not due to changes in any other variable or condition.I DON'T KNOWRESETSUBMIT ANSWER

In the __________, paper disks impregnated with antibiotics are added to a solid medium inoculated with a standard amount of a pure bacterial culture to test whether the organism is sensitive, intermediate, or resistant to the drug.ANSWERantimicrobial response testbroth dilution testE-testKirby-Bauer test

A sterile agar plate, I, is streaked with a pure culture of bacteria by means of aseptic techniques. Paper discs treated with the antibiotics Aureomycin (A) and penicillin (P) are placed at opposite sides of the plate, as shown in the diagram above. The plate is examined after a 24-hour incubation period, and a clear ring is discovered around disc A, but not around disc P. Within the clear ring around disc A, a single bacterial colony with physical characteristics like those of the pure culture is observed. A second sterile agar plate, II, is then streaked with this single colony and also incubated with antibiotics.