Lesson 5: THE COMPOUND MICROSCOPE

Question 1

an instrument that uses one or more lenses to produce a magnified image of an object that is invisible to the naked eye.

Answer 1

Microscope

Question 2

most commonly used in laboratories. It uses the principle of light microscopy (also called optical microscope) in which it uses natural or artificial transmitted light as the source of light to illuminate an object.

Answer 2

compound microscope

Question 2

A simple compound microscope can
see as tiny as

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0.1 micrometer (μm) or 100 nanometers (nm) diameter

Question 2

has high magnification but lower resolution resulting to a less sharp image compared to some advanced types of microscopes.

Answer 2

Compound Microscope

Question 2

the ability of a microscope to see a tiny object 1000 times.

Answer 2

Magnification

Question 2

should be coupled with good resolution to visualize small microorganisms; that alone will produce a blurred image.

Answer 2

Magnification

Question 2

The total magnifying power of the compound microscope is the product of

Answer 2

magnification of the objective lens and that of the eyepiece

Question 2

A simple compound microscope has a magnification power of

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10X, 40X and 100X

Question 3

The light source, usually an electric lamp, which transmits light through a translucent object for viewing and controlled by an on/off switch. You can control the amount of light entering the specimen by adjusting the diaphragm.

Answer 3

The Illumination System

Question 3

The surface or platform on which you place the microscope slide. In the center of it is an opening called aperture. On some microscopes, it is stationary and has clips to hold the slide in place. On other microscopes, it is movable and is called a mechanical stage. Movement is controlled by 2 knobs located on the top, side, or bottom of it.

Answer 3

Stage

Question 3

The area under the stage, may contain a diaphragm, a condenser, or both.

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Substage

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consisting of a single eyepiece

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Monocular

Question 3

the lenses you look through. In binocular microscopes it can be adjusted to match the distance between the eyes of different observers. The magnifications are usually stamped on the side of it (most are 10X).

Answer 3

Eyepiece/Ocular Lens

Question 3

consisting of a pair of eyepieces

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Binocular

Question 3

Light travels from the objectives through a series of magnifying lenses in it to the ocular. In some microscopes, it is straight; in others, the oculars are held at an angle. It contains a prism that bends the light rays so that they will pass through the oculars.

Answer 3

Body tube

Question 4

Attached to a rotating nose piece, or turret, at the base of the body tube are a group of 3 or 4. It focus the light that comes through the specimen, up the body tube, and through the oculars. Each of it has numbers stamped on it. One of these numbers identifies the magnification of the objective (e.g., 43X). They are usually named according to their magnifying power, as follows: scanning power 4X; low power 10X; high power 40X; oil immersion 100X.

Answer 4

Objective Lens

Question 5

regulates the amount of light passing from the light source through the specimen and through the lens system of the microscope. By properly adjusting, you can provide better contrast between the surrounding medium and your specimen, thus greatly improving your image of the specimen.

Answer 5

Diaphragm

Question 6

usually concave on 1 side and flat on the other. The flat side is usually used with the scanning and low-power objectives. used with the higher power objectives. The light source for the it is usually a lamp; natural light can be used but it is not preferred because its intensity is too variable.

Answer 6

Mirror

Question 7

You can focus your microscope by using this.

Answer 7

Coarse and fine adjustment knobs

Question 8

uses an ultraviolet light source to expose a specimen stained with fluorescent dye resulting in an emission of longer wavelength of light. Example: The bacteria stained with fluorescent dye appear as a brightly glowing object against a dark background.

Answer 8

Fluorescent Microscope

Question 9

utilizes a beam of electrons instead of a beam of light used in the light microscopy. The resolution is extremely high, theoretically 100,000 times than that of a light microscope.

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Electron Microscope

Question 10

a type of an electron microscope that provides a three- dimensional image of the object as well as high resolution.

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Scanning Electron Microscope

Question 10

another type of electron microscopy by which live organisms can be visualized based on rapid cooling of specimens by deep-freezing in liquid gas and the subsequent formation of carbon platinum replica of the specimen.

Answer 10

Freeze-etching