What structure does light pass through after leaving the condenser in a compound light microscope

specimen

Which of the following pair is matched

a) methylene blue - simple stain

b) acidic dye - capsule stain

c) crystal violet - simple stain

d) alcohol-acetone - descolorizer

e) crystal violet - basic dye

f) iodine- mordant

g) carbolfuchsin - basic day

Which of the following steps of the Gram stain are in correct order?

a) Crystal Violet

b) Iodine

c) Alcohol acetone

d) Safranin

Which of the following is true regarding the acid-fast stain

a) It is used to identify members of the genus Mycobacterium

b) acid-fast cell retain the primary dye after treatment with acid-alcohol

c) acid fast cell appear red in a completed acid fast stain

d) non-acid-fast microbes appear blue in a completed acid-fast stain

The purpose of a mordant in the Gram stain is to

prevent the crystal violet from leaving the cells

Which of the following steps is correct regarding to specimen slide preparation?

a) making a smear

b) fixing

c) staining

The negative stain is used to

visualize capsule

Simple staining is necessary to improve contrast in which microscope?

compound lightt microscope

Which microscope is used to see internal structures of cell in a natural state?

phase contrast microscope

Which microscope uses visible light?

differential interference contrast (DIC) microscope

Which microscope has the highest magnification and greatestt resolution?

electron microscope

Which microscope produces an image of a light cell against a dark background; internal structures are not visible

darkfield microscope

A virus measures 100 nm in length. What is its length in um?

0.01 um

Which microscope is not useful for observing living cells?

scanning electron microscope (SEM)

A microorganism measures 5 um in length. Its length in mm would be

0.005 mm

Which of the following correctly traces the path of light through the compound microscope?

a) light source

b) condenser

c) specimen

d) objective lens

e) ocular lens

Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light?

fluorescence microscope

Which microscope is most useful for visualizing a BIOFILM?

scanning acoustic microscope (SAM)

You are performing a Gram stain on gram positive bacteria and you stop after the addition of the first dye. What is the appearance of the bacteria at this point?

purple

You are performing a Gram stain on gram negative bacteria and you stop after the addition of the mordant. What is the appearance of the bacteria at this point?

purple

You are performing a Gram stain on gram negative bacteria and you stop after the descolorizer. What is the appearance of the bacteria at this point?

colorless

You are performing a Gram stain on gram positive bacteria and you stop after the addition of the counterstain. What is the appearance of the bacteria at this point?

purple

Which type of stain is useful in helping clinicians to decide which antibiotic to prescribe for a bacterial infection?

Gram stain

What is the total magnification of a specimen viewed with a 10x ocular lens and a 40x objective lens?

400

Which of the following provides the lowest magnification ?

scanning electron microscope (SEM)

Which microscope uses two beam of light to produce a three dimensional color image?

DIC microscope

Which microscope is used to see intracellular detail in a living cell?

two-photon microscope

Which microscope is used to observe viruses and the internal structure of thinly sectioned cells?

transmission electron microscope (TEM)

Which step in the Gram stain is the critical step in differentiating gram positive cells from gram negative cell?

alcohol-acetone

You find colorless areas in cell in a gram stained smear. What should you apply next?

an endospore stain

Which microscope is used for observing the surfaces of cell and viruses

scanning electron microscope (SEM)

The resolution of a microscope can be improved by changing the

wavelength of light

The term resolution refers to

the ability to distinguish fine structure and detail in a specimen

The courterstain used in the Gram stain is a basic dye

True

Both phase-contrast microscopy and differential interference contrast microscopy are used to view the internal structures of cells without staining

True

The capsules and flagella of bacteria can be observed in gram stained smears

False

Scanned probe microscopy is used to examine fine detail of molecular complexes, such as blood clots, molecules or DNA

True