Microscopy and magnification Flashcards
What arevthe two main types of microscopes?
Electron, and light microscopes.
Whta is the stage in light microscopes?
The place where the slide with the sample is placed on.
Where is light focused in a light microscope?
On the eye piece.
What does an eye piece graticule do?
By calibrating the eye piece graticule, we can calculate the length of the object being viewed.
define magnification.
How many times bigger an image viewed through a microscope is, compared to the real object.
define resolution.
The ability of a microscope, to distinguish between two objects that are very close together.
What does rotating the objective lens do?
change the magnification of the image.
What is the formula for magnification?
size of image : size of real object.
what is the resolution of a microscope limited by?
It is limited by the wavelenght of the light, or elecetron beam used.
Which microscope has lower resolution; light or elctron? Explain why?
Light, because the wavelength of light, is longer than the wavelength of the elctrons in a electron microscope, therefore, the light microscope has a lower resolution.
What do we call an image seen at an eletron microscope?
Electron micrograph.
What are the two types of electron microscopes
SCANNING electron microscope (SEm).
and
TRANSMISSION elrctron microscope (TEM).
Describe a scanning electron miroscope.
Detects electrons, that bounce of same surface.
and it forms a 3D image of outer surface.
Describe a transmission electron microscope.
- Detects electron transimmted through sample surface.
2.When part of sample is more dense, more electrons are being absorbed, so that part of the image is darker. Revealing the internal structure of the organelle,
What is an artefact?
Foreign objects that can appear under a microscope, that are not part of the sample.
