We use cookies to give you the best experience possible. By continuing we’ll assume you’re on board with our cookie policy

Investigating Biological Spread Essay Sample

  • Pages: 3
  • Word count: 631
  • Rewriting Possibility: 99% (excellent)
  • Category: experiment

Get Full Essay

Get access to this section to get all help you need with your essay and educational issues.

Get Access

Introduction of TOPIC

Aim: To design and perform an experiment that will show the difference between microbial growth after washing and not washing your hands.


* 8 Sterile Agar plates

* Standard soap

* Sterile paper towel

* A growth medium

Method: Eight agar plates filled with a sterile growth medium had lines drawn down the middle of the lid and a ‘W’ and a ‘U’ were drawn at the top, standing for washed and unwashed. Seven students were then asked to press three fingers into the ‘W’ side of an agar plate. The students then washed their hands thoroughly with standard soap and dried their hands with sterile paper towels. The unwashed ‘U’ side of the agar plates then also had three fingers pressed into it the same way as before. All seven agar plates and one agar plate that hadn’t been touched were left in an incubator for a week at 35?C. The results found were then researched using the Internet to find out what the different microbes were.

Results: The experiment has shown that even washing your hands doesn’t kill all microbes as seen in all agar plates except number two. This means that the experiment wasn’t conclusive however it did provide some useful information

. Most of the microbes that survived the hand washing were large colonies of fungi. The control used

Sorry, but full essay samples are available only for registered users

Choose a Membership Plan
to stop pathogens and/or contamination had to be strict while conducting the experiment and these measures were that the lids were only taken off for the shortest possible amount of time and no one was to breath on the plates. The agar plate that wasn’t touched during the process grew some microbes.


Discussion: The experiment has been a success in determining whether washing hands helps to kill bacteria and fungi. It was clear from agar plates four, five and six that some germs and fungi are resistant to soap, this could be due to natural selection which could happen when people don’t wash their hands properly and the strongest germs survive and reproduce to make a new stronger generation. However it could also be due to human error if someone didn’t wash their hands properly or someone breathed on the agar plate and it became contaminated.

From this experiment it is possible to draw the conclusion that fungi grows more rapidly if it doesn’t have to compete with other organisms. This can be seen in agar plate number four, five, seven and three where no fungi can be seen in the unwashed section yet in the washed section with no other competitors it thrives.

The most frequently found microbe on the unwashed side of the agar plate was the staph, however on all of the plates except number four, the staph were either killed or significantly slowed down. One explanation for number four to be the only one to still have a significant number of staph after washing is that it is a different or stronger strain of staph.

It is clear that some contamination was present in all of the agar plates because the eighth plate was not opened, it was just left near the others while the experiment was carried out.

Conclusion: The experiment showed the difference between microbial growth when you wash and don’t wash your hands. However the results returned were not as expected as in some of the agar plates’, large quantities of microbes were found.

We can write a custom essay on

Investigating Biological Spread Essay Sample ...
According to Your Specific Requirements.

Order an essay

You May Also Find These Documents Helpful

Designing an Osmotic Potential Experiment with Potatoes

Osmosis is used throughout the kitchen in various countries. In France, aubergines and cucumbers are often soaked in salt to create a nicer texture, however chefs lack understanding of why this happens, as they would have forgotten about it after they finished school, they only know that it happens. Therefore, this experiment is designed to explain to the millions of chefs around the world why the water is “sucked” out of a vegetable when it is dipped into a salt or sugar solutions. I believe that having knowledge over the reason for something can open up new ways of thinking; this is why I think it is so important to explain the reason behind this phenomenon. Famous chefs are also known to be under time pressure; for example, every cooking show on TV includes some sort of time pressure scenario, weather it is a ticking clock or waiting customers. For...

Investigating the Effects of Salt on Seed...

PROBLEM/RESEARCH QUESTION In this investigation, we are researching and investigating whether the concentration/percentage of NaCl (salt) in water affects the germination rate of seeds and if so, which concentration germinates the most seeds. We will formulate our research by conducting an experiment in which we will observe the germination of seeds in various concentrations of salt water and evaluate the results gathered. In particular, we will measure the percentage of seeds germinated in one week and formulate our conclusions from there. HYPOTHESIS I hypothesise that the highest percentage of seeds will germinate in the petri dish that contains the lowest percentage of NaCl in water- 0.5% salt salinity and the percentage will decrease as the percentage of salt in the solution increases. I predict this because I know from prior knowledge that seeds need to be able to absorb H2O to germinate and salt prevents this. So if we increase...

Investigating the Effect of Sodium Fluoride on...

Graph Showing the effect different volumes of Sodium Fluoride has on the average rate of production of H+ ions as measured by the colour change of resazurine Comment on Graph: The graph depicts a positive trend, as the amount of Sodium Fluoride increases the average rate of H+ ions as measured by the colour change of resazurine also increases. This increase is consistent with each 5 mL increase of Sodium Fluoride resulting in an increase of one assigned numerical colour. This steady increase plateaus at 15mL with no further colour change. Conclusion and Evaluation Conclusion In our experiment we tested whether changing the amount of Sodium Fluoride effects the rate of respiration as measured by the colour change of resazurine. Our experiment indicates that there is a relationship between sodium fluoride and the rate of respiration. In our experiment the more sodium fluoride that was added the less colour change,...

Popular Essays


Emma Taylor


Hi there!
Would you like to get such a paper?
How about getting a customized one?