a&p lab 2

This is the formula for calculating the diameter of an unknown microscope field.

diameter of field A × total magnification of field A = diameter of field B × total magnification of field B

You should always begin observation of specimens with the oil immersion lens.

false

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

fine adjustment knob

Drag the labels onto the diagram to identify the parts of the compound microscope (1 of 2). (figure 3.1)

left column: arm mechanical stage right column: ocular lense rotating nosepiece stage objective lenses condenser iris diaphragm lever

Drag the labels onto the diagram to identify the parts of the compound microscope (2 of 2). (figure 3.1)

left column: condensor knob coarse adjustment knob fine adjustment knob light control right column: mechanical stage controls substage light base

Recall from the video the parts of a typical compound microscope. Drag the labels to identify the parts of the compound microscope. Not all labels will be used. 1

left column: head mechanical stage coarse adjustment knob right column: nosepiece stage condenser mechanical stage controls light control

Recall from the video the steps for properly focusing on a specimen using a compound microscope. Remember to always use both eyes when looking through binocular lenses! Place the steps for focusing a microscope in the correct order from left to right.

left to right: - Click the scanning objective into position above the specimen. - Use the coarse adjustment knob to move the stage all the way up. - Use the fine adjustment knob until the specimen is in focus. - Adjust the iris diaphragm and/or the light control knob to improve contrast. - Use the mechanical stage controls to move a given structure to the center of your field of view.

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

lowest

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

lowest-power, coarse

You prepare a wet mount of your own cheek cells and place it under the microscope, but find that you cannot see any detail of the cells. What can you do to make details more visible?

prepare another slide and stain with methylene blue

How do you clean the lenses of your microscope?

with special lens paper and cleaner

You are looking at a slide of three crossed threads. Yellow is on the bottom, blue is in the middle, and red is on the top. When you rotate the adjustment knob forward (away from you) on your microscope, the stage rises. You move the adjustment knob to focus on the middle thread. As you rotate the adjustment knob forward, which color thread will come into focus next?

yellow

You are observing the letter "e" under a compound microscope. Which of the following indicates how the image appears as you view it through the ocular lens?

ə

Define the following microscopy terms. Drag and drop the correct terms on the left to complete the sentences.

- TOTAL MAGNIFICATION is the power of the ocular lens multiplied by the power of the objective lens used. - PARFOCAL microscope objectives stay relatively in focus when magnification is changed. - RESOLUTION is the ability to discriminate between two close objects. - WORKING DISTANCE is the space between the bottom of the objective lens and the surface of the slide. - FIELD OF VIEW is the area you see through the microscope.

If your ocular lens is 10×, and you are using your 45× objective lens to view a slide, the total magnification is ________.

450x

How could you best improve the contrast of this specimen?

Open or close the iris diaphragm.

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

As you increase the total magnification of the specimen, the working distance ________.

decreases

Recall from the video the parts of a typical compound microscope. Drag the labels to identify the parts of the compound microscope. Not all labels will be used. 2

left column: arm condenser knob fine adjustment knob right column: ocular lenses objective lenses iris diaphragm lever substage light base

The working distance for a 10× objective lens is ________.

much greater than the working distance for the 100× objective lens

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

nosepiece

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

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

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

use the coarse adjustment knob only with the lowest-power objective

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

resolution (or resolving power)