Assignment #1 Critical Thinking
Mindy Easterwood
6/15/2021
2-A) When focusing a light microscope, why is it best to adjust the focus using the coarse focusing knob before using the fine focusing knob? [Please read Chapter#2 for help]
2-B) What would the results of Pasteur’s swan-neck flask experiment have looked
like if they supported the theory of spontaneous generation? [Please read Chapter#3 for help]
Adjusting a light microscope is a delicate process that requires certain steps to get the best possible view of a specimen. The coarse focus moves the lens closer to the glass slide at a faster rate. This helps the user get a better rough image. On the other hand, the fine adjustment moves the lens at a
slower rate, which allows sharper details to be viewed. Therefore, it is best practice to use the coarse adjustment first to bring most of the sample into focus, then use the fine focus to enhance and define the image.
Spontaneous generation is the belief brought forth by early scholars that life can arise from nonliving matter, so long as it had “vital heat”. If Pasteur’s experiment had supported the theory of spontaneous generation, the outcome would have been different. The boiled broth inside the flask with the swan necks still intact would also have microbial growth. Broth could be considered “vital heat” since it is derived from animals or plants. A result such as this would have fallen in line with the possibly ill performed experiments of John Needham. None of the experiments involving spontaneous generation could have been possible without the invention of the microscope. Scientists would have kept believing that maggots grew on meat left out in the open, despite Francesco Redi setting out to refute this. On the other hand, microscopes would
not have been invented if humans were not curious about life around them. It seems like the world needs both the desire to learn and the desire to create to have a full picture.
