Introductory Lab

How could you best improve the contrast of a specimen?

Open or close the iris diaphragm.

Which of the following sentences regarding microscope care and handling is correct?

Use the coarse adjustment knob only with the lowest-power objective.

You are looking at very lightly stained cells under the microscope, and you want to increase the contrast so that you can see them "better." You ________ the iris diaphragm to ________ the light.

close, dim

The ________ is a substage lens that concentrates light on the specimen

condenser

As total magnification increases, the depth of field ________.

decreases

As you increase the total magnification of the specimen, the size of the field ________.

decreases

When using the higher power objective lenses, you would use this part of the microscope to focus the specimen.

fine adjustment knob

field of view

is the area you see through the microscope.

total magnification

is the power of the ocular lens multiplied by the power of the objective lens used.

working distance

is the space between the bottom of the objective lens and the surface of the slide.

When observing a slide under a microscope, begin focusing with the ________-power objective lens in place.

lowest

Parfocal

microscope objectives stay relatively in focus when magnification is changed.

The total magnification of an object can be found by ________.

multiplying the power of the objective lens by the power of the ocular lens

The ________ of the microscope carries three or four objective lenses.

nosepiece

The ability to discriminate two close objects as separate is called ________.

resolution (or resolving power)

Before putting away the microscope in the storage cabinet you must observe all of the following except ________.

rotate the highest power objective lens in position

The microscope slide rests on the __________ while being viewed.

stage

When you want to study a slide under the microscope, you place it on the ________.

stage

Resolution

the ability to discriminate between two close objects.

Your lab microscope is parfocal. This means that __________.

the slide should be almost in focus when changing to higher magnifications

To transport a microscope, hold it ________.

upright, with one hand on its arm and the other hand supporting its base

You begin your observations using the ________ lens and the ________ adjustment knob.

west-power, coarse