Exam 2: Microscopy

It was possible to view viruses only after the invention of the electron microscope because they are too small to be seen with a light microscope.

Confocal microscopes,in combination with specialized computer software,can be used to create three-dimensional images of cell structures.

Small internal cell structures are best visualized with a

The __________ is the point at which a lens focuses parallel beams of light.

The __________ is the distance between the center of a lens and the point at which it focuses parallel beams of light.

The __________ is the distance between the specimen and the objective lens when the specimen is in focus.

Negative staining with India ink can be used to reveal the presence of capsules that surround bacterial cells.

Immersion oil increases the amount of light passing through a specimen and entering the objective lens.

Negative staining facilitates the visualization of bacterial capsules which are intensely stained by the procedure.

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

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

Prior to staining,smears of microorganisms are heat-fixed in order to

Mordants increase the binding between a stain and specimen.

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

Which of the following is considered to be a differential staining procedure?

__________ is the process by which internal and external structures of cells and organisms are preserved and maintained in position.

In the Gram-staining procedure,the primary stain is

If the decolorizer is left on too long in the Gram-staining procedure,gram-positive organisms will be stained __________ and gram-negative organisms will be stained __________.

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

Basic dyes such as methylene blue bind to cellular molecules that are