A leaf is placed under a microscope and nothing can be seen

First of all, you need to make slices to see the leaves that cannot be placed directly under the microscope. Because the light of an ordinary light microscope cannot penetrate the multi-layered tissues of leaves.

Secondly, after the film is loaded, you need to use the microscope correctly, and give you a brief description of the next steps.

Adjust the microscope light source to make the mirror.

or the light from the microscope illuminator just passes through the aperture.

Adjust the aperture. Choose the right aperture (small aperture is good for light, and clear light is not good for light.)

Larger aperture, in turn to larger). A bright white field of view can be seen from the eyepiece.

Place the slide on the stage, generally taking care to keep the tissue in the clear hole**. This is how to image.

Adjust the coarse knob to determine where you want to observe the tissue (start by lowering the lens close to the loading without touching, and gradually adjust it upwards). At the same time, move the film left and right to find the part you want to see (if you want to see the left, move it to the left, and if you want to see the bottom, move it down, in short, it is the same as looking directly).

Replace the high-magnification lens and adjust the fine adjustment knob (the same as the coarse adjustment knob, but more fine), so that you can clearly see the cell morphology to be observed.

Note: 1) Descend to the highest and then gradually ascend. When lowering the lens, do not press against the coverslip, as it is easy to damage the mounting, and it is easier to damage the lens.

2) The lens should be changed from a low magnification, because the higher the magnification, the smaller the field of view.

3) When adjusting both focus knobs, you should be slow so that you will not cause damage to the microscope and will not be unable to see the layer of cells you are looking for.

This is my experience, if you don't understand, let's ask.

First of all, the microscope you said is a biological microscope, or a stereo microscope (also called a dissecting lens), if it is a biological microscope, it is normal to not be visible, the reason is illumination, the biological microscope is transmitted light illumination, and the light must pass through the leaves in order to reach the objective lens. If you are using a biological microscope, you can't directly observe the leaves, of course, low magnification is okay, but you have to have enough lighting, you can see the light and light through the leaves. Otherwise, consider a stereo microscope.

The leaves are not transparent to light, and of course they cannot be seen, and the reason why the microscope can magnify the object to be inspected is through a lens.

It is possible that the magnifying glass is not used correctly.

No, because the leaves are too thick to be transparent to the light. The reason why the microscope can clearly show the structure of an object is that it is refracted by the mirror at its bottom.

The leaves are too thick and need to be sliced so that you can see them.

Excuse me, is your microscope using correctly?

No, because the leaves are a bit thick, light is not easy to penetrate, and the material to be observed under the microscope must be thin and transparent, so if you want to observe the structure of the leaves, you can do freehand slicing.

No, the leaves are too thick to let through the light. Optical microscopes require light to pass through to see. It's like putting a hand directly on it. But make it into flakes and you're good to go!

But you don't see clearly, you need to process the material that you're looking at, make a slide specimen, and then look at it, and what you see are the little cells of the leaves, the branches, and so on.

Microscopic double-mirror imaging is made using the principle of optics, and the visible light must pass through the observed object, and if it is not transparent, it cannot be imaged in the visual field Therefore, the specimen material observed with the microscope must be thin and transparent, because the light can pass through the material Therefore, a student puts a leaf under the microscope to observe, but cannot see its structure clearly, because the material is too thick for the light to pass through

Therefore, b

Microscopes use optical principles to imaging, and the material observed must be thin and transparent; If it is opaque, the light cannot enter the eye through the observed material through the objective lens and eyepiece, and form an image image image on the retina A leaf, a hair, and a finger are opaque, and the light cannot be transmitted, so a leaf or a hair or a finger is placed in the light hole, and the field of vision is dark when observed with a microscope, resulting in inability to see clearly

Therefore, choose D

One is that they are too thick to pass through the light, so naturally they cannot be seen, but maybe a little thinner (two layers of cells...).The second is that they have no microstructure, and they can be seen in vain, so there is no microscopic lens clamp that is large enough to hold the pencil case. Otherwise, why would we have to work hard to make all kinds of glass slide specimens?

The microscope is magnifying things at the nanometer, micrometer level, and if you take a very small part of the things that you mentioned, you can image them.

The amount of light transmitted, but the scanning microscope is OK 0 0

Conventional microscopes are not OK, non-translucent, but microscope lenses or scanning types are fine.

I have seen a microscope lens with 10 times magnification, that is, a 40 times reading, and the microscope has no scientific and technological content, and it can be seen clearly in the state of natural light.

Microscopes use optical principles to imaging, and the material observed must be thin and transparent; If it is opaque, the light cannot enter the eye through the observed material through the objective lens and eyepiece, and form an image image image on the retina A leaf, a finger, and a soybean seed are opaque, and the light cannot be transmitted, so a leaf or a finger or a soybean seed is placed in the light hole, and the field of vision is dark when observed with a microscope, resulting in inability to see clearly, and a tomato juice smear must be made into a glass specimen to observe A tomato juice smear is thin and transparent, and can be observed directly under an optical microscope

Therefore, choose D

ACD, human hair, a leaf, fingerprints, are not thin and transparent, not materials observed with a microscope, ACD is incorrect;

b. A drop of pond water is a material that can be observed with a microscope, and B is correct

Therefore, b