bio156 quiz 3

1 of 25

What property of a compound light microscope enables a person to change objectives without major focusing adjustments?

	resolving power
	magnification
	parfocal
	focusing
	resolution

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2 of 25

How does closing the iris diaphragm affect image brightness and contrast?

	decreases both
	increases both
	decreases brightness and increases contrast
	increases brightness and decreases contrast
	decreases brightness but has no effect on contrast

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3 of 25

Which of the following objectives has the shortest working distance?

	4X
	10X
	45X
	100X

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4 of 25

What effect will changing from the low power objective to the high power objective have on the field of view of a specimen?

	increase
	decrease
	no effect

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5 of 25

If the letter p is placed under the microscope in the normal reading position, which of the following orientations of the letter would the viewer see?

	b
	p
	q
	d

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6 of 25

Which of the following procedures should be done just prior to adjusting the diopter, when using the compound microscope?

	Clean all lenses with lens paper
	Turn the light on
	Adjust the iris diaphragm
	Adjust the fine focus

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7 of 25

Two parts of the microscope that regulate the amount of light visible through the ocular are the:

	fine and coarse adjustment knobs
	ocular and objective lenses
	illuminator and revolving nosepiece
	condenser and iris diaphragm

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8 of 25

Initial focusing of any slide is done under the:

	scanning or low power objective
	high power objective
	oil immersion objective
	depends upon the size of the specimen

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9 of 25

Under which magnification would the distance between the objective and the specimen being observed be the least?

	40X
	100X
	450X
	1000X

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10 of 25

What is the total magnification produced by a microscope, using a 10X ocular lens and a 10X objective lens?

	10X
	20X
	100X
	1000X

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11 of 25

Which of the following describes proper microscope care and technique.

	Be sure to carry the microscope upright, with one hand on the arm and the other under the base.
	To protect the optics of the microscope, place it down gently and don't drag it across the tabletop.
	Always begin focusing with the lowest power lens available.
	Only use the coarse focus knob with the scanning and low power lenses.
	All the above are examples of correct microscope care and technique.

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12 of 25

Turning which of the following knobs moves the objective lenses the greatest vertical distance?

	coarse focus knob
	fine focus knob

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13 of 25

Resolution is the ability to see two objects as separate.

	True
	False

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14 of 25

Which of the following regulates the amount of light passing through the slide specimen on the microscope stage?

	nosepiece
	objective lens
	iris diaphragm lever
	fine focus knob

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15 of 25

An increase in magnification causes

	a decrease in the field of view.
	a decrease in the working distance.
	a decrease in the depth of field.
	all of the above.

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16 of 25

Working distance is the

	distance from your house to your job.
	distance the microscope nosepiece travels using the coarse focus knob.
	distance from the bottom of the objective lens to the specimen.
	distance the specimen can travel across the microscope stage.

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17 of 25

When adjusting a binocular microscope for differences between right and left eyes, focus the microscope with the fine adjustment while viewing only with the right eye (fixed ocular).

	True
	False

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18 of 25

When using the oil immersion lens, you should raise the objective lenses for easy application of an oil droplet to the slide.

	True
	False

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19 of 25

Why must a small object seen through the ocular lens be centered in the field of view, before changing to a higher power objective lens?

	to prevent damage to the objective lens
	to compensate for the decrease in resolving power of the lens
	to prevent its disappearance due to the decrease in the field of view
	to prevent eyestrain

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20 of 25

A parfocal microscope allows you to quickly focus using the low power or scanning lens and then, to switch to a higher power lens with only a minimal adjustment of the fine focus knob.

	True
	False

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21 of 25

Why is it necessary to adjust the amount of light after changing objective lenses?

	Higher magnification lenses require more light.
	Proper lighting is needed to see specimen details.
	The lens aperture decreases with higher magnification lenses.
	All of the above.

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22 of 25

Which objective would you use to locate a specimen on a slide?

	lowest power available
	high power
	oil immersion
	any of the ojectives could be used with equal success

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23 of 25

Which of the following parts of the microscope would increase the depth of field?

	ocular
	high power objective
	fine focus
	low power objective

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24 of 25

Depth of field is best demonstrated with

	a slide showing the letter e.
	a slide containing overlapping threads.
	the light turned completely off.
	the oil immersion lens.

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25 of 25

When the letter e slide is viewed with the microscope, it appears

	right side up.
	right side up and backwards.
	upside down.
	upside down and backwards.