• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. 14
  15. 15
  16. 16
  17. 17
  18. 18

The effect of toliet cleaning products on E-coli

Extracts from this document...


Is the bacteria Escherichia coli (e coli) adversely affected (killed) by King white cleaning products. Higher level biology 14/04/2010 Contents page Page Content 1 Title page 2 Contents page 3 1.1.1- Focus question, 1.1.2- Hypothesis, 1.1.3- Theory 4 1.2.1- Variables , 1.2.2- Control experiment 5 1.3.1- Martials and apparatus, 1.3.2- Safety aspects 6 1.3.2- Safety aspects (cont) 7 1.3.3- Method, 1.3.4- Experimental setup 8 2.1.1- Changes to experimental design 2.1.2- Qualitative data , 2.1.3- Raw data table 9 2.2.1- Overview, 2.2.2- Calculations, 2.2.3- Experimental setup 10 2.3.1- Processed data table, 2.3.2- Process data graph 11 3.1.0- Conclusion 12 3.1.0- Conclusion (cont) 13 3.2.0- Limitations of experimental design 14 3.3.0-Impovements to experimental design 15 Bibliography 1.1.0 Experimental design 1.1.1 Focus question- Is the bacteria Escherichia coli (e coli) adversely affected (killed) by King white cleaning products. 1.1.2 Hypothesis - King White toilet cleaner will most adversely affect (kill) the bacteria Escherichia coli (e coli) to the highest degree when compared to a range of toilet cleaning products. 1.1.3 Theory- Escherichia coli (E coli) are bacteria which causes severe stomach cramps and diarrhoea. It is the leading cause of bloody stools and in older people/younger children certain strains of e coli can be fatal (Family doctor, pg 1, 2008). E coli are common bacteria in humans and some mammals. It is vital in the body as it produces vitamin K as a by-product and is generally a harmless pathogen providing that it remains within the large intestine. However its bi-product becomes negatory when e coli move into other diameters of the body such as the stomach. The bacteria are most commonly transmitted by consuming tainted meat, contaminated water, and raw milk and between cattle workers. However the bacteria may also be transmitted by unhygienic bathroom practise (Pinkster E, pg 1, 2007). E coli is found in human waste which is passed through bathroom toilets, hence some of these e coli bacteria may contaminate bathroom surfaces. ...read more.


These zones where circular but many where not perfectly circular. Some had diameters that where larger than others. The measurement of diameter was taken from the largest point for all samples. Some zones of inhibitions crossed with other and some even hit the edges of agar plate, like the other samples the largest complete diameter of these particular samples was found. 2.1.3- Raw data table (table 3) - The diameter in millimetres of the zone of inhibition in a e coli growth colony after 24 hours when tested with different cleaning products. Sample Diluted water (mm+0.1) Bleach (mm+0.1) Harpic toilet cleaner (mm+0.1) Home brand toilet cleaner (mm+0.1) Duck toilet cleaner (mm+0.1) King white toilet cleaner (mm+0.1) 1 0 34 15 8 7 20 2 0 33 19 16 10 29 3 0 30 12 11 11 26 4 0 27 17 13 9 34 5 0 25 19 15 13 33 2.2.0 Processing raw data 2.2.1- Overview- Each different cleaning product showed results that were fairly similar. Hence the independent values can be averaged (including the calculation of standard deviation). This average will represent the average diameter of the zone of inhibition for a given substance. These averages with respective standard deviations will be placed into a bar graph so that the effectiveness of different products can be visually compared. 2.2.2- Calculations used (table 4) Statistical Analysis Formulae Sample Calculation Mean X=Mean value X=Sum of all values n= Number of values Mean of bleach diameter (mm+0.1) X=(34+33+30+27+25)+0.1/5+0.1 =29.8mm +0.1 Standard Deviation X -X)2= Variance squared N= Number of values is system /4 (mm) =3.83mm standard deviation 2.2.3- Experimental setup (figure 2)- inserted a bit later 2.3.0 Presenting raw data 2.3.1- Processed data table (table 5) - The average diameter (mm2) of the zone of inhibition of e coli growth colonies after 24 hours for difference different cleaning products. Diluted water Bleach Harpic toilet cleaner Home brand toilet cleaner Duck toilet cleaner King white toilet cleaner Avenge diameter (mm+0.1) ...read more.


Systematic Use better research methods to find how the specific chemical make-ups of different solutions would affect bacteria, or view dead bacteria under a microscope to examine physiological changes. Some samples had higher viscosity then others Systematic Allocate a static volume for each solution and use the volume for each sample. Some samples diffused more than others Systematic Physically spread solutions (dense and thin) over the same surface diameter to reduce the impact of diffusion. Unequal spreading of e coli over agar plates Systematic Use the continuous line cross section grid method to ensure the bacterial colonies are equal in size/density, and have been drawn from the same source. Movement of agar plates Systematic The movements of agar plates should be kept to an absolute minimum. This can be achieved through improved experimental practice. For instance the agar plate should be open, e coli colonies prepared, and then all samples placed within the same time period. Using this method the agar plate only needs to be opened once. Shape of the zone of inhibition Random The number of substances on each agar plate should be reduced or the size of the agar plates should be increased. This will help to ensure the a more accurate circle is produced (does not collide with agar plate edges, ect) Decontamination mechanism was shared amongst others Systematic The decontamination mechanism (methylated sprits) was shared with another experimenter using different solutions. For the purpose of decreasing the opportunity for cross contamination individual decontamination mechanisms should be employed. It may also be responsible to use separate decontamination vessels for individual substances. Timing of recording results Random The recording of results should be taken as per the experimental design. If this time cannot be reach by the experimenter then another or partner experimenter should be requested to record results. Movement in the diameter of the experiments Random Distractions and the movement of other experimenters increase the chance of cross contamination and other random errors. Future experiments should be performed away from other experimenters and a solitary environment. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    Neurology and Behaviour. Focus question: Is there an increase in the perception and ...

    5 star(s)

    rather also the amount of exposure the individuals had had to each of the items pictured in the survey. This theory is supported by the large standard deviation in the female participants in comparison to the male participants. This suggests that the female participants had a more varied response to

  2. Biology Lab Report - Effects of Mouthwash on Oral Bacteria

    Distilled Water iii. Bar Graph 7. Conclusions and Evaluation i. Which mouthwash was most effective at killing on slowing growth of mouth bacteria? Support your answers using your observations and data. Mouthwash B: Scope-Mint. It showed an average zone of inhibition of 1.4cm, the highest average zone of inhibition on bacteria compared to the other mouthwashes.

  1. Biology IA - Investigation of the relationship between surface area and volume using different ...

    However, as the sizes of agar cubes were different, not in all of them the NaOH solution reached the center. Table 2 says that the higher the surface area to volume ratio the higher the diffused to possible distances ratio, and vice versa - the lower the surface area and volume ratio, the smaller part of cube is diffused.

  2. Modelling Surface Area to Volume Ratio in Cells with Agar Cubes

    Fill the beaker with hydrochloric acid and put the 1cm3 agar cube into the beaker, making sure to completely immerse the cube in the acid. 3. Start the stop watch as soon as you put the agar cube into the HCL. 4. Write down any qualitative observations you see. 5.

  1. What is the effect of different body positions i.e. lying down, sitting and standing ...

    movement of arms * legs straight * movement * hands tensed when monitor was switched on * Legs crossed * Relaxed * slight movement * not talking * Talking * Relaxed * movement of hand * faulty monitor (had to wait for results twice)

  2. Ecology Design IA

    pH level, so therefore changes in water pH may affect an organism's ability to function correctly - Experiment to be conducted in the same area - Cannot be controlled, so therefore will be measured Weather of site - Whether the weather conditions are favourable to an organism's adaptations may affect

  1. Surface Area to Volume Ratio Simulation Experiment. The comparison between surface area : volume ...

    : 1.0 surface area to volume ratio only needed 1459.12 seconds to decolourise. These observations and results proves that the ratio of surface area : volume is a limiting factor in cell size. Many important chemical reactions occur within the cell.

  2. Osmosis Experiment. This experiment is to consider how salinity influences osmosis in potato cells.

    Average difference (+0.001g) Standard deviation 0 0.095 0.022 0.2 0.027 0.01 0.4 -0.035 0.026 0.6 -0.054 0.046 0.8 -0.093 0.041 This table shows the average difference and standard deviation for each salt concentration investigation. 2.3.2 GRAPH 1: Results Graph This graph shows the average mass of potato cubes after osmosis.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work