Technological Advances of the Microscope 1.5 – pg. 24-25
NAME:
1. Give one advantage of a compound light microscope over a single-lens microscope.
One advantage is that greater magnification without reduced clarity could be seen in a specimen
being viewed by a compound light microscope compared to specimen viewed by a single-lens
microscope. Using two lenses, the compound light microscope allows for a maximum magnification
of 2000x whereas the single-lens microscope can only magnify a little more than 10x. Thicker lenses
provided greater magnification, but because thicker lenses distort light more than thinner lenses, as
the lenses become thicker the images magnified blur more and less detail can be made out. This is
why 2000x magnification is the limit for a compound light microscope.
2. Give one advantage of a scanning electron microscope over a transmission electron
microscope.
The scanning electron microscope (SEM) has the following advantages over the transmission electron
microscope (TEM):
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Living things can be viewed by a SEM
A SEM provides a wider field of view since it doesn’t magnify as much as a TEM
Things viewed by a SEM do not have to be encased in plastic
A SEM creates a 3-D image of the thing it views
3. Describe differences in the appearance of algae cells when viewed with each of the
microscopes.
When viewed by a single-lens microscope, you can see the arrangement of the cells. With a compound
light microscope, some of the internal structures of the cell are visible. Then using the transmission
electron microscope those internal structures can be viewed in greater detail. The scanning electron
microscope shows the three-dimensional structure of the algae cell.
4. Which microscope would you recommend for viewing each of the following? Give reasons
for your choice.
a) the detailed structure of a cell’s nucleus
I would recommend using the transmission electron microscope for viewing the detailed structure of
a cell’s nucleus because this microscope can magnify up to 2 000 000x is a much higher level of
magnification than any other microscope and will provide a very detailed image of the structures in
the nucleus. Also, the TEM allows the internal structures of the nucleus to be viewed whereas the SEM
only provides a three-dimensional image of the outside of the cell and is unable to penetrate into the
cell and nucleus to provide images of their internal structures.
b) a single cell
Using both a transmission electron microscope and a compound light microscope would be good in
this situation since neither will kill the cell, but I would recommend using the compound light
microscope rather than the TEM because it is easier, cheaper and more accessible to prepare a
specimen to be viewed by the light microscope.
5. Imagine that you could direct a team of technologists to invent a new microscope. What
would you want that new microscope to do? How would this benefit society?
It seems like the TEM is the best microscope because it allows for the greatest degree of magnification
(2 000 000x) by far than any other microscope, but its biggest drawback is that the cells examined
under this microscope cannot be examined while they are still alive. Therefore, I would want the new
microscope to be able to examine the insides of cells while they are still alive and at a high level of
magnification so that great detail can be observed. This would benefit society because a lot of
important detailed observations of cells, their structures, how they work, and what’s actually
happening within the structures when they are attacked by disease compared to when they are
working normally will be observed while the cell is still alive. In this case it may be easier to figure out
how to stop the diseases from happening.