Microscopy Compound

Question 1

There are two general categories of microscopes

Answer 1

light microscope
electron type

Question 2

uses light waves and lenses that are associated with the light microscope

Answer 2

light microscope

Question 3

employs electron beams and magnetic fields to produce the image.

Answer 3

electron type

Question 4

Other types of microscope:
where the microscope field is brightly lighted and the object to be observed appears dark die to its ability to absorb or refract some of the incident light

Answer 4

bright field

Question 5

Other types of microscope:
where the object appears luminous against a dark background since it reflects some of the incident light in all directions

Answer 5

dark-field

Question 6

Other types of microscope:
which uses UV light, thereby allowing greater resolution and
magnification. It is used principally to detect or even measure substances in specimens of living tissues that are known to absorb UV light at particular wavelengths. UV is not visible to the eye, so the image formed is recorded with the use of cameras or a television screen.

Answer 6

Ultraviolet (UV)

Question 7

Other types of microscope:
which makes use of the property of certain chemical substances that release light at a different wavelength when exposed to UV rays. Such substances convert UV light into visible waves of greater length. Bacteria and other
microorganisms are stained with fluorescent stain that can be detected in a microscope illuminated with UV light.

Answer 7

Fluorescent

Question 8

Other types of microscope:
which utilizes the refraction that occurs when light passes from
one medium into another of different density. The special objectives and condenser intensify slight differences in contrast produced by this bending of right. It is useful in studying the internal structures of microorganisms because
structures differing in refractive index from the surrounding protoplasm become visible, and their sizes and locations can be determined.

Answer 8

Phase-contrast

Question 9

The wide ___ keeps the microscope steady at any position of the stage.

Answer 9

base

Question 10

The ___, fastened to the base through the inclination joint, permits the ___

Answer 10

arm; adjustment of the stage to a desired angle.

Question 11

The ____ reflects the light into the condenser.

Answer 11

concave mirror

Question 12

The ____ concentrates the light rays received from the mirror and sends them to the objective.

Answer 12

condenser

Question 13

The___ is a horizontal platform upon which the specimen to be examined is placed. At the center of the stage is a circular aperture.

Answer 13

stage; circular aperture.

Question 14

The ____ hold the slide in place on the stage.

Answer 14

stage clips

Question 15

The ___ is that part of the optical system of the microscope which produces the specimen’s initial magnified image (real) within the body tube.

Answer 15

objective

Question 16

The student microscope has three objectives:

Answer 16

a dry low power
a dry high power
oil immersion objective

Question 17

an optical constant of the lens system, is the distance from the center of the lens to the point where parallel rays entering the lens are brought to a focus

Answer 17

Focal length

Question 18

an objective is that property to recognize features of a specimen that are close to each other as separate or distinct. The greater the resolving power, the greater the definition of an objective. This property is dependent on the wavelength of light used and an optical property of the objective lens known as a numerical aperture

Answer 18

Resolving power

Question 19

a measure of the resolving power of an objective. An
objective with a 0.25 N.A. allows the viewer to distinguish as separate 25,000 lines per inch. If the specimen is known to be of the order of 26,000 lines per inch, the observer
can never see the line as separate no matter how much magnification is employed. Lenses with higher magnification usually have higher N.A. but the medium through which the
light passes also affects N.A. N.A. is indicated in the side of the lens.

Answer 19

Numerical aperture (N.A.)

Question 20

means that the objectives are optically ad mechanically designed so that the distance between the specimen and the aerial image is always constant. Slight refocusing
with the aide of the fine focus knob is sufficient to restore critical sharpness of the image after changing from one objective to another, thus, the coarse focus knob need not to be operated.

Answer 20

Parfocal

Question 21

which parfocal objectives are attached, allows convenient
shifting of the objectives.

Answer 21

revolving nosepiece

Question 22

is a hollow cylindrical tube through which light passes from the objective to the eyepiece. The upper portion of this is called the ________.

Answer 22

body tube; draw tube

Question 23

is that part of the optical system through which the specimen is viewed. The intermediate image projected by the objective is enlarged by the eyepiece. Hence, the term compound microscope is derived from the fact that the specimen is magnified twice, first by the objective and second by the eyepiece. The final image formed is a virtual image.

Answer 23

eyepiece or ocular

Question 24

used to bring the objective into approximate focus

Answer 24

coarse focus knob

Question 25

For maximum definition, the __ is used

Answer 25

fine focus knob

Question 26

Consist of systems of lenses

Answer 26

The condenser, the objective and the eyepiece

Question 27

Comprise the optical system.

Answer 27

The mirror, the condenser, the objective and the eyepiece