The counterstain in the acid-fast stain is
a basic dye
Which microscope is used to see internal structures of cells in a natural state?
Phase-contrast microscope
Which microscope takes advantage of differences in the refractive indexes of cell structures?
Phase contrast microscope
The appearance of gram-positive bacteria after addition of the first dye in the Gram stain.
purple
Which microscope uses two beams of light to produce a three-dimensional, color image?
DIC microscope
The purpose of the ocular lens is to
Magnify the image from the objective lens
The appearance of gram-negative bacteria after addition of the mordant in the Gram stain.
purple
Which of the following microscopes uses visible light?
DIC
In this microscope, the observer does NOT look at an image through a lens.
electron microscope
Cells are differentiated after which step in the Gram stain?
alcohol acetone
The counterstain in the Gram stain is
a basic dye
In Figure 3.1, line "a." points to the microscope's
ocular lens
What is the total magnification of a chloroplast viewed with a 10x ocular lens and a 45x objective lens?
450x
The appearance of gram-positive bacteria after adding the counterstain in the Gram stain.
purple
In which microscope does the image look like a negative stain?
Darkfield microscope
Which microscope achieves the highest magnification and greatest resolution?
electron microscope
Which microscope is used to see intracellular detail in a living cell?
two-photon microscope
Place the following steps in the correct sequence:
1-Staining;
2-Making a smear; 3-Fixing.
2,3,1
The appearance of gram-negative bacteria after addition of the decolorizing agent in the Gram stain.
colorless
Which of the following pairs is mismatched?
Select one:
a.
Darkfield microscope - uses visible light
b. Scanning electron
microscope - produces a three-dimensional image
c. Scanning
tunneling microscope - allows visualization of atoms
d. Confocal
microscope - produces a three-dimensional image
e. Fluorescence
microscope - uses a fluorescent lighte. Fluorescence microscope - uses
a fluorescent light
Fluorescence microscope - uses a fluorescent light
Place the steps of the Gram stain in the correct
order:
1-Alcohol-acetone; 2-Crystal violet; 3-Safranin; 4-Iodine.
2-4-1-3
This microscope produces an image of a light cell against a dark background; internal structures are NOT visible.
darkfield microscope
Which microscope is used to see detail of a 300-nm virus?
electron microscope
What Gram reaction do you expect from acid-fast bacteria?
Gram-positive
The resolution of a microscope can be improved by changing the
wavelength of light
In Figure 3.1, line "b." points to the microscope's
objective lens
The purpose of a mordant in the Gram stain is
to prevent the crystal violet from leaving the cells
Bacterial smears are fixed before staining to
affix the cells to the slide and kill the bacteria
Simple staining is often necessary to improve contrast in this microscope.
compound light microscope
You find colorless areas in cells in a Gram-stained smear. What should you do next?
an endoscope stain
What structure does light pass through after leaving the condenser in a compound light microscope?
specimen
Assume you stain Bacillus by applying malachite green with heat and then counterstaining with safranin. Through the microscope, the green structures are
Endospores
The best use of a negative stain is
to determine cell size and to determine cell shape
In Figure 3.1, line "c." points to the microscope's
condenser
Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light?
fluorescence microscope