Exam 2: Microscopy

Scanning tunneling electron microscopes create a three-dimensional image of specimens at atomic level resolution.

The designer of the first transmission electron microscope,_________________,was awarded the 1986 Nobel Prize in physics.

Scanning electron microscopes bombard specimens with a stream of electrons; however,the specimen image is produce by electrons that are derived from atoms of the specimen itself rather than by the electrons used to bombard the specimen.

The procedure in which a single stain is used to visualize microorganisms is called __________ staining.

If the objective lenses of a microscope can be changed without losing focus on the specimen,they are said to be

Light rays are refracted (bent)when they cross the interface between materials with different refractive indices.

The special dyes used in fluorescence microscopy that absorb light at one wavelength and emit light at a different wavelength are called __________.

A microscope that exposes specimens to ultraviolet,violet,or blue light and forms an image with the light emitted at a different wavelength is called a __________ microscope.

Acid-fast organisms such as Mycobacterium tuberculosis contain __________ constructed from mycolic acids in their cell walls.

If you forgot to apply the safranin counterstain while performing a Gram stain,which outcome would you expect?

A 45* objective and a 10*ocular produce a total magnification of

After the decolorizer has been added,gram-positive organisms are stained __________ and gram-negative organisms are stained __________.

Which type of microscopy would be preferred for showing fine internal detail of the eukaryotic organelles?

As the resolution of a microscope system improves,the size of the smallest object that can be seen clearly

As the magnification of a series of objective lenses increases,the working distance

Atomic force microscopes use a scanning probe that maintains a fixed distance from the surface of the specimen.It is useful for specimens that

In transmission electron microscopy,spreading a specimen out in a thin film with uranyl acetate,which does not penetrate the specimen,is called

An electron microscope uses __________ lenses to focus beams of electrons onto a specimen.

If immersion oil was replaced with water,what would happen?

In the Gram-staining procedure,the primary stain is