Tripod magnifier device drawing. The device of magnifying devices and the rules for working with them

History reference Light microscopes with two lenses were invented in the 16th century. In the 17th century, the Dutchman Anthony van Leeuwenhoek designed a more advanced microscope, giving a magnification of up to 270 times. And in the 20th century it was invented electron microscope, magnifying the image by tens and hundreds of thousands of times.

How to determine the magnification of a microscope? Multiply these numbers. The product will indicate the magnification, which in this moment gives a microscope. For our example, this is 10 x 20 = 200 times. If you move the lens or change the eyepiece (on the microscope shown, it can be smoothly rotated by changing 10 to 20), then the magnification changes accordingly. Remember this! It is important to indicate magnification when working on an object.

Rules for working with a light microscope 1. Place the microscope with a tripod towards you against your left shoulder at a distance of cm from the edge of the table. 2. Lower the telescope down 1-2 mm from the stage. 3. Direct the light with a movable mirror onto the stage. Rotate the mirror carefully, while looking into the eyepiece, achieving lighting that is comfortable for the eye: not “beating”, but not “cloudy”.

4. Place the finished preparation on the object table opposite the hole in it. Clamp the glass slide with clamps. 5. Look into the eyepiece with one eye, without closing or closing the other. 6. While looking into the eyepiece, very slowly raise the telescope with the screws until a clear image is obtained. 7. After work, put the microscope back in its case.

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The lesson is part of the "Cellular Structure of the Body" section. The work program was compiled on the basis of the Law of the Russian Federation “On Education”, the Federal State Educational Standards for Basic General Education, the general education program in biology for grade 5 “Biology. Bacteria, fungi, plants” edited by V. V. Pasechnik. Textbook for educational institutions edited by Professor V.V. Pasechnik “Biology. 5-6 grades”. Moscow “Enlightenment”, 2012.

Venue: Biology room.

Didactic goals (for the teacher): creating conditions for the assimilation of knowledge by each student on the topic of the lesson.

Goal (for students): formation of knowledge about the device magnifying devices and rules for dealing with it.

• Educational: to acquaint students with the material on the history of the discovery and the device of magnifying devices, the rules for working with a microscope.
• Educational: to maintain a steady interest in knowledge among students, to cultivate a sense of responsibility for the result of their work, to continue work on the formation of communication and reflective qualities.
• Developing: to continue the development of logical thinking, to teach the ability to highlight the main thing, to generalize and transform the information received.

Methods and methodological techniques: visual (demonstration of a presentation, magnifying devices), verbal (explaining the rules for working with magnifying devices, safety instructions when working with glass equipment), working with sheets of individual knowledge control, performing practical work, raising a question of problematic content, pair work, independent work in individual knowledge control cards, a method of independent solution of calculation problems, practical.

Lesson type (according to GEF OOO): discovery of new knowledge. Applying them in practice in the course of laboratory work.

Equipment for the teacher: interactive complex, PC, multimedia presentation.

Equipment for students: a magnifying glass, a light microscope, a ready-made micropreparation, a textbook.

Formed UUD:

• Cognitive UUD: definition key concepts: lens, eyepiece, tube, tripod, object stage, mirror; independent formulation of the goal, putting forward proposals for the problem posed.
• Communicative UUD: planning educational cooperation with the teacher and students, the implementation of joint cognitive activities in pairs.
• Regulatory UUD: the ability to give self-assessment to one's actions, to correlate what is known with what is not yet known, the ability to transform information from one type to another.

During the classes:

1. Organizing time. Hello guys, sit down. Today we will begin to explore the amazing world invisible to the usual eye.

2. Actualization of knowledge. You know that kingdoms are distinguished in nature. Can you name these kingdoms?

Children's answers: Kingdoms of Bacteria, Fungi, Plants, Animals and Viruses.

teacher question: organisms of some kingdoms you can see naked eye, but some are not. Who do we not see, but know that they exist?

Children's answers: bacteria and viruses.

Teacher: That's right, and we can't see some very small single-celled animals, plants, and fungi without magnification. The topic of today's lesson: the device of magnifying devices (slide 1).

This lesson will interesting topics that the knowledge that you receive in the lesson can immediately be applied practically! (slide 2).

At the end of the lesson, you will need to know the magnifying glass and microscope. Rules for working with magnifying devices. Be able to: work with a magnifying glass and a microscope (slide 3).

3. The stage of assimilation of new knowledge and methods of action.

So, we start the laboratory work (slide 4). Since this is your first laboratory work, I draw your attention to the fact that first we write in the notebook the name of the laboratory work “The device of a magnifying glass and a light microscope. Rules for working with them. Each work indicates the purpose of the laboratory work:

• study the device of a magnifying glass and a microscope,
• Familiarize yourself with the microscope.

We will work with you step by step (slide 5).

Stages of work:

1. Introduction to magnifying glass.
2. Introduction to the microscope.
3. Learning the rules of working with a microscope (setting).
4. Examination of preparations under a light microscope.
5. Verification test.

(Slide 6) we begin our acquaintance with the simplest magnifying device that you may have already met - this is a magnifying glass. Looking through a magnifying glass. We will be able to see living organisms magnified from 2 to 20 times.

(Slide 7) you have magnifiers on your desks, let's look at the parts of a magnifier.

The rules for working with a magnifying glass are very simple: We take the handle and bring it closer to the object until it is clearly visible (slide 8).

(Slide 9). Now, knowing the structure of a magnifying glass and the rules for working with it, complete the task: Take a magnifying glass and look at the text in the textbook.

Guys, please answer the question: what objects can be considered if you are a scientist - a biologist.

Suggested answers of children: small insects, flowers.

(Cry). Indeed, you are right, with the help of a magnifying glass you, as young researchers, can examine small animals and plants in more detail.

(Slide 10). And now we begin to get acquainted with the microscope.

Microscope in Greek means small and I look - a device designed to obtain enlarged images, as well as to measure objects or structural details that are invisible or poorly visible to the naked eye.

(Slide 11). In fact, it is very difficult to name the first inventor of the microscope, because in the 16th century, so many people were fond of polishing glass. In 1595, Zacharius Jansen mounted two convex lenses inside a single tube, thus laying the foundation for the construction of compound microscopes. Robert Hooke with the help of a microscope improved by him, he observed the structure of plants and gave a clear picture, which for the first time showed the cellular structure of elderberry cork. He also coined the term "cell" in 1665.

(Cry). On the slide you see Robert Hooke's microscope and cells as he first saw them.

(Slide 12 and 13). Time to start studying the device of the microscope. Our school microscope consists of mechanical and optical parts.

(Slide 14 and 15). In order to find out the magnification of a microscope, you need to multiply the number on the eyepiece by the number on the objective.

Slide 16. So, the product of two numbers will show the magnification of the microscope.

Slide 17. Guys, let's start studying the rules for working with a microscope. It is very important that we work sitting at our desk. You need to put the microscope in the middle of the desk, with the tripod towards you. Please note that during operation it is IMPOSSIBLE to move it! Look at the slide and find the error in the picture. Children's answer: we put a tripod towards us.

Slide 18. Well done! We continue our acquaintance with the rules of working with a microscope. Looking into the eyepiece with one eye and using a mirror with a concave side, direct the light from the window into the lens, and then illuminate the field of view as evenly and as much as possible.

Slide 19. Put the micropreparation on the stage so that the object under study is under the lens.

Slide 20. Looking from the side, lower the objective with the macro screw until the distance between the lower objective lens and the micropreparation is 4-5 mm. Think about why it is impossible to lower the screw while looking into the eyepiece? Children's answer: you can crush the glass slide.

Slide 21. Here is a microscope, prepare it for work, observing all safety rules when working with a microscope. We proceed to the most interesting: examining micropreparations under a light microscope.

Place the prepared onion peel micropreparation on the object table under the clamps.

Consider micropreparation. What did you see? Children's answer: cells.

Let's get to the test. Slides 23-31.

slide 32. Homework: Questions after paragraph 6.

Thank you for your attention!

Literature

1. Pasechnik V. V. Biology. bacteria. Mushrooms. Plants. Grade 5 Textbook / M.: Bustard, 2014.

2. Pasechnik VV Biology. Biology. Bacteria, fungi, plants. Grade 5 Workbook to the textbook by V.V. Pasechnik. Test tasks of the exam. Vertical / M .: Bustard, 2014

3. Pasechnik VV Biology. bacteria. Mushrooms. Plants. Grade 5 Toolkit/ M.: Bustard, 2014