Bio 110 Lab 6 Flashcards
light microscopes use
light rays passing thru lenses to magnify the object.
stereomicroscope is also called the
dissecting microscope
the steromicroscope is designed to study the
entire object in 3D at low magnification
the compound microscope is used for examining
small or thinly sliced sections of objects under higher magnification than the stereomicroscope.
the term compound in compound microscope refers to
the use of two sets of lenses.
the 2 sets of lenses in a compound microscope are:
the ocular lenses and the objective lenses
illumination in a compound microscope is from
below.
in a compound light microscope light
is from below, then visible light passes thru clear portion of the specimen, but does not pass thru opaque portions.
to improve contrast with a light microscope
stains or dyes that bind to cellular structures and absorb light is used
photomicrographs or light micrographs
are images produced by a compound light microscope
electron microscopes use
beams of electrons focused on a photographic plate by means of electromagnets to magnify the object
transmission electron microscope is comparative to
the compound light microscope
the object viewed with a TEM is
ultra-thinly sliced and treated with heavy metal salts to improve contrast.
the scanning electron microscope is comparative to
the dissecting light microscope
the object viewed with a SEM is
an image of the surface and dimensions of an object
the EM has a greater
resolving power
resolution is
the minimum distance between 2 objects at which they can still be seen as 2 separate objects.
what gives a much greater resolving power
the use of high energy electrons
CLM have _____ lenses
TEM have ______ lenses
glass
electromagnetic
CLM illumination is by
TEM illumination is by
visible light
beam of electrons
CLM resolution is approx.
TEM resolution is approx.
200 nm
0.1 nm
CLM magnifies to
TEM magnifies to
2,000x
1,000,000x
CLM costs up to
TEM costs up to
tens of thousands
hundreds of thousands
the stereomicroscope allows you to
view objects in 3D at low magnifications.
the stereomicroscope is used to study
entire small organisms, any object requiring lower magnification, and opaque objects that can be viewed only by reflected light. called a stereomicroscope because it produces a 3D image.
binocular head
(DS)holds 2 eyepiece lenses that move to accommodate for the various different individuals’ eyes
eyepiece lenses
(DS)the 2 lenses located on the binocular head
independent focusing eyepiece
fixed eyepiece
(DS) some models have and a knob to allow independent adjustment of each eye.
non adjustable eyepiece
focusing knob
(DS) knob located on the arm, used for changing focus of both eyepieces together.
magnification changing knob
(DS) often built into the binocular head, used to change the magnification in both eyepieces simultaneously. may be a zoom mechanism or a rotating lens mechanism of different powers that clicks into place.