"Tools for Exploring Life" PPT courseware

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"Tools for Exploring Life" PPT courseware

Part 1: Understand the microscope and understand the basic structure of the microscope

observe

What are the characteristics of eyepieces?

The longer the eyepiece lens, the smaller the magnification, so it is inversely proportional.

What are the characteristics of the objective lens?

The longer the objective lens, the greater the magnification, so it is directly proportional.

The smaller the working distance, the higher the magnification; the larger the working distance, the lower the magnification.

Mechanical part of the microscope

Function: Place the lens

Bring eyepieces and objective lenses together

Coarse focus spiral

Mechanical part of the microscope

Function: Lifting and lowering the lens barrel, with a large lifting range

Rotate counterclockwise to raise the lens barrel; rotate clockwise to lower the lens barrel.

Tools for exploring life PPT, Part 2: Using a microscope How to use a microscope

1. Taking the mirror and placing it

1. Hold the mirror arm with your right hand and support the mirror base with your left hand.

2. Place the microscope slightly to the left in front of the experimental table.

2. Select eyepieces and objective lenses

1. Eyepiece: Generally choose one with a smaller magnification (5×).

2. Objective lenses generally choose smaller magnifications (10×).

(Magnification = eyepiece magnification × objective lens magnification)

3. Aiming at the light

1. Rotate the converter to align the low-magnification objective lens with the clear aperture.

2. Choose a larger aperture and align it with the light aperture, look at the eyepiece with your left eye, and turn the reflector so that the light is reflected into the lens barrel through the aperture. Through the eyepiece, you can see a bright white field of view.

Tools for Exploring Life PPT, Part 3: Frequently Asked Questions in Microscope Operation (Practice)

1. How to determine whether the stain in the field of view is on the mounting film, the eyepiece, or the objective lens?

2. The problem of light and dark vision

(1) When observing the specimen, if you find that the upper part of the field of view is darker and the lower part is brighter, you should adjust ( )

A. Eyepiece B. Objective lens C. Aperture D. Reflector

(2) Part of the observed field of view is clear and part of the cells are blurred. This is because ( )

A. The reflector is not adjusted properly. B. The specimen is cut into uneven thickness.

C. The fine focus screw is not adjusted properly. D. The microscope objective lens is damaged.

3. Use a low-magnification objective lens to observe the thin piece of paper printed with the word "F". The words in the field of view are ( )

4． Use a microscope to observe onion epidermal cells. The eyepiece used for the first time is 10× and the objective lens is 10×. The eyepiece used for the second time is 5× and the objective lens is 10×. The object image seen in the field of vision for the second time is compared with the object image seen for the first time ( )

A. It is half of the original number, and the number of cells increases.

B． It is 2 times the original number and the number of cells increases

C. It is half of the original number, and the number of cells is reduced.

D. It is 2 times the original number, and the number of cells is reduced.

5. Does the low-power lens or the high-power lens have a wider and brighter field of view? Why?

The field of view of a low-power lens is large, more light passes through, it is bright, and the magnification factor is small;

The field of view of a high-power lens is small, less light passes through, it is darker, and the magnification factor is large.

6. Why should we first observe clearly with a low-power lens, then move the object image to be magnified and observed to the center of the field of view, and then use a high-power lens to observe?

If you observe directly with a high-magnification lens, you often cannot find the object because it is not within the field of view. Therefore, it is necessary to first observe clearly with a low-power lens, move the object image to be magnified and observed to the center of the field of view, and then use a high-power lens to observe.

7. After using the converter to turn the high-power lens, is it possible to turn the coarse focus screw?

no. Observe with a high-magnification lens and only need to make slight adjustments. Turning the coarse focus screw may easily damage the glass slide.

Tools for exploring life PPT, Part 4: Precautions

When making temporary mounting films, should you take the material and then drip it with water, or should you drip it with water and then take it out?

Drop the water first and then take the materials

Before observing, you need to align the light first and rotate the objective lens to align it with the light aperture. Should the objective used for focusing light be a low-power objective or a high-power objective?

Low magnification objective lens

Align it with the light and then place the slide specimen, or place the slide specimen and then align it with the light?

Focus on the light first, then place the specimen

You see the cell image in the upper left corner of the field of view. Before turning to high power, you need to move this object to the center of the field of view. In which direction should you move?

Move to upper left

Keywords: Jiangsu Education Edition seventh-grade biology PPT courseware free download, tools for exploring life PPT download, .PPT format;

For more information about the PPT courseware "Exploring Life and Exploring Life's Tools", please click the Exploring Life ppt and Exploring Life's Tools ppt tag.

"Tools for Exploring Life" PPT:

"Tools for Exploring Life" PPT Part One: Situation Introduction The rich and colorful biological world contains infinite mysteries, which are waiting for us to explore. Scientific exploration is inseparable from some instruments. Learning Objectives 1. Explain the basic structure and...

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Update Time: 2024-11-20

This template belongs to biology courseware Jiangsu Education Edition Seventh Grade Biology Volume 1 industry PPT template

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