As the light microscope was made very early on, as mentioned once before, it does have a lot of limitations due to that age.
The only and maybe the most significant problem is its inability to show the finer details of any specimen. The light microscope obviously uses light and a type of refraction of it, to show the magnified specimen. However no matter hoe much you magnify the sample it does not increase in the level of detail. This is due tot the resolution which stubbornly does not change.
From this point forward we must ask ourselves; what is resolution? Resolution is the facility to distinguish between two objects. For example cells can be magnified but as the pixels of it get closer together, the light particles- photons- can not get through it. The background of light is that, light can not pass through anything half its wavelength. For instance, white light is 0.55µm and anything smaller than 0.275µm is way too small for light to sufficiently pas through. Therefore this means to achieve resolution for a finer and more detailed image something else should pass through the gaps; something smaller than photons.
This is where the electron microscope comes to play. This recent finding uses electrons, as they are miniscule, to give a higher resolution and with that comes greater detail.
The electron microscope is relatively larger and uses a vacuum and electrons to produce a high quality image, by sending electrons through the tiny gaps. (An anode is there to speed it up). This gives an advantage to the electron microscope, a better resolution. As a result if any person wants to see something such as the mitochondrion, the Golgi Body or even a lysosome they are able to. It magnifies up to 200,000 times, which is a huge amount!
There are two types of electron microscope, the Scanning Electron Microscope [SEM] and the Transmission Electron Microscope [TEM]. Scanning Electron Microscope shows the external and whole image of a specimen such as a dust mite, or a nit. The Transmission Electron Microscope is literally the opposite. It gives the image from the interior. These are very exciting options as they give an overview of the entire specimen in question and we are able to study them in great detail and depth.
On the flip side there are again disadvantages of using the electron microscope, as with everything else in the world. It is deadly complicated to use and require special expertise or training. It is also very expensive relative to the light microscope. As well as those factors it is very expensive and is in mono colours: black and white.
Adding to that, movement of the species cannot be observed by the scientists; the samples have to be dead to be put through the electron microscope. This is because electrons are used to get the better image and this all happens in a vacuum. Clearly if you had air, the electrons will knocked by the air particles and it has to be in that magnetic field. This is the reason why it has to be dead.
To conclude, light and electron microscope are both equally as useful as well as being limited in their own way, it recommend that in order to get the more satisfying ultra structure image to use the electron microscope and the light one for something less accurate and more general.
To finish I am going to draw up a table, of advantages and disadvantages of each microscope- for an easy reading.
By Aswani Pillai 6L3
Here's what a star student thought of this essay
Quality of writing
There was a typo in the work. This shows the lack of proof reading at the basic level as the word processor should pick this up automatically. The appropriate technical terms were used but the student needs to show a proper understanding of such terms by either defining them in a glossary or explaining them in the body of the work. The student follows the typical layout of the work, although they do not follow the typical presentation of the work. The colours are not best suited to a piece of coursework like this.
Level of analysis
The student's analysis is poor for A level. They do not explore deeply enough into the reasons behind how the microscopes work by explaining it using fundamental physics that they have learned from the syllabus. Their judgements, however, were suitable and the relevant evidence was used to support it even if it was not supported by detailed evidence. To improve, they need to go back and explain why - re-reading over their work they will find that there were many areas where the question of "why?" or "and?" arose. Such questions should not occur if a piece of work answers the question fully.
Response to question
The comparison of advantages and disadvantages is done very well but the level of detail is lacking. The student simply tends to state the advantages and disadvantages and for A level, I believe they should have explored deeper into the reasons behind it. Why is the microscope limited in the way that it is? How does it work on a fundamental level? I think such questions are key to answering the question fully and appropriately for this level. Their response is very clearly written but not necessarily clearly presented. I feel light blue is not the best colour to use for a piece of work like this.