Question 1

The magnifying powers of the usual microscope objectives are:&#10;A) 5&#215;, 10&#215;, 20&#215;.&#10;B) 10&#215;, 20&#215;, 40&#215;.&#10;C) 10&#215;, 40&#215;, 80&#215;.&#10;D) 10&#215;, 40&#215;, 100&#215;.

Accepted Answer

The objectives are the major part of the magnification system.There are usually three objectives on each microscope,with magnifying powers of 10×,40×,and 100×.

Question 2

Oil needs to be removed from the:&#10;A) ocular.&#10;B) 10&#215; objective.&#10;C) 40&#215; objective.&#10;D) 100&#215; objective.

Accepted Answer

Oil must be removed from the oil-immersion (100×)objective immediately after use by wiping with clean lens paper.If not removed,oil may seep inside the lens or dry on the outside surface of the objective.The high-dry (40×)objective should never be used with oil; however,if this or any other objective or microscope part comes into contact with oil,it should be cleaned immediately.

Question 3

The phase-contrast microscope differs from the brightfield microscope because of changes in:&#10;A) the objective.&#10;B) the condenser.&#10;C) the oculars.&#10;D) both a and b.

Accepted Answer

The phase-contrast microscope is basically a brightfield microscope with changes in the objective and the condenser.An annular diaphragm,or ring,is put into (or below)the condenser.This condenser annulus is designed to let a hollow cone or "doughnut" of light pass through the condenser to the specimen.A corresponding absorption ring is fitted into the objective.Each phase objective must have a corresponding condenser annulus.Use of each phase objective requires an adjustment of the condenser to "match" the annular diaphragm and the phase absorption ring.

Question 4

In a polarizing microscope,the polarizing filters are:&#10;A) placed on top of each other.&#10;B) placed at right angles to each other.&#10;C) red and blue in color.&#10;D) used to brighten the field being observed.

Accepted Answer

A polarizing filter may be defined as a sieve that takes ordinary light waves,which vibrate in all directions,and allows only light waves of one orientation (north-south or east-west)to pass through the filter.One of the polarizers is rotated until the two are at right angles to each other.

Question 5

The definition of K&#246;hler illumination is the:&#10;A) strength of the transmitted light.&#10;B) light path through the microscope.&#10;C) light path passing through the condenser of the microscope.&#10;D) light path passing through the diaphragm of the microscope.

Accepted Answer

When properly aligned,the microscope is adjusted in such a way that the light path through the microscope,from the light source to the eye of the observer,is correct.This is referred to as Köhler illumination.

Question 6

The most common type of microscope illumination system used in the clinical laboratory is:&#10;A) brightfield.&#10;B) phase contrast.&#10;C) polarizing.&#10;D) fluorescent.

Accepted Answer

With few exceptions,brightfield illumination has been the primary type of microscope illumination system used in the routine clinical laboratory.Other illumination systems are also available,including phase-contrast,interference-contrast,polarizing,darkfield,fluorescence,and electron microscopy.

Question 7

Fluorescent objects (natural,stained,or labeled)can be seen with a fluorescent microscope because they absorb the ____ light and emit light of yellow or ____ wavelength.&#10;A) blue; green&#10;B) red; orange&#10;C) green; purple&#10;D) purple; red

Accepted Answer

Certain objects have the ability to fluoresce,which means they absorb light of certain very short (ultraviolet)wavelengths and emit light of longer (visible)wavelengths.In fluorescence microscopy with transmitted light and a compound microscope,the darkfield condenser is preceded by a special exciter filter that allows only shorter wavelength blue light to pass and cross on the specimen plane.If the specimen contains an object that fluoresces (either naturally or because of staining or labeling with certain fluorescent dyes),it will absorb the blue light and emit light of a longer yellow or green wavelength.

Question 8

Total magnification is the product of the magnification of the objective ____ the magnification of the ocular.&#10;A) added to&#10;B) multiplied by&#10;C) divided by&#10;D) subtracted from

Accepted Answer

The total magnification observed is the product of the magnifications of these two lenses.In other words,the magnification of the objective multiplied by the magnification of the ocular equals the total magnification.

Question 9

The term ocular is another name for the microscopic ____ that magnifies an image.&#10;A) objective&#10;B) eyepiece&#10;C) diaphragm&#10;D) nosepiece

Accepted Answer

The ocular,or eyepiece,is a lens that magnifies the image formed by the objective.The usual magnification of the ocular is 10 (10×); however,5× and 20× oculars are also generally available.Most microscopes have two oculars and are called binocular microscopes.

Question 10

The definition of the microscopic working distance is the distance from the:&#10;A) bottom of the objective to the material being studied.&#10;B) ocular to the bottom of the objective.&#10;C) ocular to the material being studied.&#10;D) top of the objective to the material being studied.

Accepted Answer

The working distance is the distance from the bottom of the objective to the material being studied.The greater the magnifying power of a lens,the smaller is the focal length and thus the working distance.This becomes very important when the microscope is being used,because the working distance is very short for the 40× (4 mm)and 100× (1.8 mm)objectives.For this reason,correct focusing habits are necessary to prevent damaging the objectives against the slide on the stage.

Question 11

An artificial neural network:&#10;A) simulates the action of a robot.&#10;B) simulates human brain processing of information.&#10;C) simulates automated instruments.&#10;D) follows strict algorithms.

Accepted Answer

The answer of An artificial neural network:&#10;A) simulates the action...

Question 12

The definition of microscopic resolution is:&#10;A) an indication of how small individual dots can be and still be recognizable.&#10;B) an indication of how close individual objects (dots) can be and still be recognizable.&#10;C) the point at which the appearance of two dots results in a dumbbell appearance.&#10;D) both a and b.

Accepted Answer

The answer of The definition of microscopic resolution is:&#10;A) an...

Question 13

The numerical aperture (NA)is:&#10;A) an index of the resolving power of a lens.&#10;B) the distance from an object being viewed to the lens.&#10;C) inscribed on each objective lens.&#10;D) both a and b.

Accepted Answer

The answer of The numerical aperture (NA)is:&#10;A) an index of...

Question 14

The most dramatic change in microscopy in the last 3 decades,has been:&#10;A) invention of the electron microscope.&#10;B) the ability to digitize images.&#10;C) the ability to transmit microscopic images electronically.&#10;D) both b and c.

Accepted Answer

The answer of The most dramatic change in microscopy in...

Question 15

A brightfield microscope may be converted to a darkfield microscope by:&#10;A) use of a special darkfield condenser in place of the usual condenser.&#10;B) replacement of the usual filters.&#10;C) use of a special ocular.&#10;D) changing the type of light source.

Accepted Answer

The answer of A brightfield microscope may be converted to...

Deck 5: The Microscope