Light Microscope Flashcards
Label the light microscope
A-tube B-rotating nose piece C- objective lens D-stage clips E-diaphragm and condenser F-light source G-eyepiece (ocular) H-arm I-stage J-coarse adjustment K-fine adjustment L-base
What is the tube for in a light microscope
Provides a pathway for the light from the objective to the eyepiece
What is the rotating nose piece for in a light microscope
A disc, containing different objective lenses that can rotate to allow the different objectives to be used
What is the objective lens for in a light microscope
Convex lenses of different strengths to enlarge the image
What is the diaphragm for in a light microscope
Can be opened and closed to allow more or less light to pass through the specimen
What is the condenser for in a light microscope
the condenser is a lense that focuses the light from the light source onto the specimen
What are the stage clips for in a light microscope
The stage clips keep the microscope slide in position on the stage
What is the light source for in a light microscope
An electric or a mirror providing light that will be directed towards the specimen
What is the eyepiece (ocular) for in a light microscope
Convex lenses lenses to enlarge the image, the eyepiece usually has a magnification of 10x
What is the arm for in a light microscope
The arm connects the upper part, containing the lenses with the lower part, containing the light source. The microscope needs to be picked up by the arm
What is the stage for in a light microscope
A platform that supports the microscope slide over an opening which allows light to pass through from below
What is the coarse adjustment for in a light microscope
Rapidly moves the stage up and down to focus the image when the small objects are being used. You always start with this
What is the fine adjustment for in a light microscope
Slowly moves the stage up and down to focus the image when the longer objectives are being used
What is the base for in a light microscope
The base is very heavy and has a large surface area to support the weight of the microscope, preventing it from falling over
What are the limitations of a light microscope
A light microscope cannot be used to distinguish objects that are smaller than half the wavelength light
What type of microscope can be used where a light microscope is not suitable
An electron microscope
How does an electron microscope function
Electrons are speeded up in a vacuum until their wavelength is extremely short. Beams of these fast moving electrons are focused on a cell sample and are absorbed or scattered by the cell’s parts so as to form an image on an electron sensitive photographic plate
What’s re the two types of electron microscopes
Scanning electron microscope (SEM) and transmission electron microscope (TEM)
What is the drawback of an electron microscope
Since no living specimen can survive under the high vacuum, they cannot show the ever changing movements that characterize a living cell
