1. Grade-7-Q2-Module-1-Parts-and-Functions-of-the-Compound-Microscope-and-its-Manipulation-2nd-Ed.pdf
- 1. “Una sa tanan, BATA: Buligan, Amligan, Tudluan, Alalayan!” DIVISION OF BACOLOD CITY Science Quarter 2 Self-Learning Module 1: Parts and Functions of the Compound Microscope & its Manipulation 7
- 2. 2 Science – Grade 7 Quarter 2 Self-Learning Module 1 – Parts and Functions of the Compound Microscope & its Manipulation Second Edition, 2021 Republic Act 8293, section 176 states that: “No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties”. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education Schools Division Superintendent: Gladys Amylaine D. Sales, CESO VI Assistant Schools Division Superintendent: Peter J. Galimba PhD Printed in the Philippines by Department of Education – Region VI – Division of Bacolod City Office Address: Rosario-San Juan Sts., Bacolod City 6100 Telefax: (034) 704-2585 E-mail Address: bacolod.city@deped.gov.ph Development Team of the Self Learning Module Writer: Maria Victoria Valencia-Ponce Editors: Aline D. Vieja, Joey Ian C. Singson Reviewer: Edna Rose P. Gueco Illustrators: Layout Artist: Maria Victoria Valencia-Ponce Management Team: Janalyn B. Navarro Edna Rose P. Gueco Ellen G. Dela Cruz
- 3. 3 This module was designed and written with you in mind. It is here to help you identify parts of the microscope and their functions (S7LT-IIa-1) and to use appropriate techniques in using and manipulating the compound microscope (S7LT-IIb-2). The scope of this module allows you to use it in many different learning situations. The language used recognizes the diverse vocabulary level of students. The lessons are arranged to follow the standard sequence of the course. But the order in which you read them can be changed to correspond with the textbook you are now using. • Lesson - Parts and functions of the microscope and Techniques in using and manipulating the compound microscope. After going through this module, you are expected to 1. identify the parts and functions of the microscope, 2. to focus the specimens using the compound microscope from high objectives to low objectives, and 3. to handle microscope properly. Lesson Parts and Function of the Compound Microscope and its Manipulation For several years, humans have been exploring for tools and instruments that will help them in discovering something that is microscopic or cannot be seen by the naked eye. The invention of the lens has led to the discovery of the microscope, it is an important tool which helps people see tiny objects and living organisms. The microscope allows you to see things due to its properties, such as magnification and resolution. Lesson Overview I Need to Know
- 4. 4 Magnifying power or Magnification is the ability of the microscope to make images or specimen bigger. The magnification of a specimen can be calculated by multiplying the number found in the eyepiece with the number found on the objective being used. So, if a specimen is viewed using a 10x objective and a 10x eyepiece. It will be magnified 100times/100x. Resolving power or Resolution is the capacity of the microscope to distinguish small gaps between two separate points which humans cannot distinguish. Two types of microscope: Simple microscopes are composed of one lens and provide relatively low magnifying power (5x). A magnifying glass is a good example of a simple microscope. Compound microscope, also called a light microscope, are composed of two or more lenses that provide powerful magnification. It uses diffused light, a light which is not harsh and direct from the sun or artificial light to illuminate the object or specimen to be observed. The parts of a Compound Microscope are categorized into three: 1. Illuminating parts are parts that provide light. The light may come from two sources: natural source, reflected sunlight and artificial source, light bulb. 2. Magnifying parts are the parts that enlarge the object or specimen 3. Mechanical parts are the parts of the microscope that supports, adjust, connect and move other parts. A. Table 1: PARTS AND FUNCTIONS OF THE COMPOUND MICROSCOPE. Parts Function Eyepiece or Ocular (A) Located at the top of the body tube where the observer peeps through at the enlarged image of the specimen. Magnifies the object ten times (10x). Body tube (H) Cylindrical part which connects the lenses of the objectives and the ocular. Course adjustment knob (B) The large knob that moves the body tube up and down to focus the specimen viewed under the low power objectives (LPO). Fine adjustment knob (C) Is the smaller knob that is used to get sharp focus of the specimen viewed under the high power objectives (HPO) Revolving nosepiece (I) Is a rotating disc located at the bottom of the body tube that holds the different objectives and allows the shifting of the objectives from the low-power objectives to the high-power objectives.
- 5. 5 Objective Lenses - Low Power Objectives (LPO) (D) - High Power Objectives (HPO) (M) - Scanner-Power Objective Lens (N) Lens located under the revolving nose piece which gather light and magnify the image. - Low Power Objective (LPO) enlarges the specimen 10x. It provides the general view of the specimen. - High Power Objective (HPO) enlarges the specimen 40x. It provides the detailed parts of the specimen. - Scanner-Power Objective Lens enlarges the specimen 4x. Stage (F) A platform with an opening to let the light pass where the specimen in a glass slide is mounted. Stage clips (E) Hold the slide in place so that it will not move. Arm (O) Supports the body tube and the part that is held when the microscope is carried from one place to another. Diaphragm (J) It regulates the amount of light that will pass through the stage. Mirror (K) Reflects the light from the source to the specimen for viewing. Inclination joint (G) Allows you to tilt the microscope into different angles. Base (L) Supports the entire body of the microscope. Figure 1: Parts of the microscope Techniques in using and manipulating the compound microscope. A. Focusing a Compound Microscope
- 6. 6 1. Get the microscope from its box or the cabinet. Do this by holding the microscope with both hands, the one is supporting the base and the other is holding the arm. 2. Put it on a flat tabletop slowly and carefully with its arm facing you. Place it about 17 centimeters or about 6 inches away from the edge of the table. 3. Clean all glass surfaces with lens paper. Start with the eyepiece, then do the objectives and end with the mirror. Use a clean tissue paper or soft cloth like old t-shirt to clean the mechanical parts of the microscope. 4. Incline or tilt the body facing light in such a way that you are comfortable with it. 5. Look through the eyepiece or ocular with one eye but do not close the other eye. Remember that you always need to keep both eyes open while looking into the microscope to avoid eyestrain. 6. Adjust the mirror so that the light will focus toward the hole of the diaphragm. CAUTION: Never use direct sunlight as a Light source to view objects under the microscope. Direct sunlight can burn the retina of the eye and cause blindness. 7. Adjust the diaphragm under the stage so that a medium amount of light gets through. 8. Place the slide on the stage, hold it firmly with the slide clips on each side. Center the specimen on the slide over the stage window. 9. Watching from the side, carefully lower the body tube using the course adjustment knob until the end of the Low Power Objective (LPO) almost touches the cover slip. 10. Look through the eyepiece with both eyes open, closing the other eye can strain your eyes. And remember: everything is backward and upside down! Moving the slide to the right puts the image to the left and vice versa. Slowly turn the course adjustment upward/downward until the specimen appears clearly. 11. To shift to the High Power Objectives (HPO), raise the body tube first using the course adjustment knob. Looking from the side, turn the revolving nosepiece to the High Power Objectives (HPO) in place. Use the fine adjustment knob to lower the High Power Objectives (HPO) till it almost touches the cover slip. Look through the eyepiece and adjust the fine adjustment knob until the specimen is seen clearly. Current microscope models are said to be Parfocal. This means the image in clear focus under the low power objective, remains focused after shifting to high power objective. B. Storing a Compound Microscope 1. Turn the revolving nosepiece until the Low Power Objectives (LPO) is in place. 2. Slowly lower the body tube so that the end of the objective is approximately 1 centimeter (1 cm) above the stage. 3. Position the clips so that they do not exceed beyond the sides of the stage. 4. Rotate the diaphragm until the smallest opening is in position.
- 7. 7 5. Let the mirror stand on its edge with the concave side facing the user to protect it from dust. 6. Some microscope boxes have a socket for the eyepiece. In this case, remove the eyepiece from the body tube and place it in the socket. 7. Put back the microscope’s plastic cover. If the original plastic cover has been lost or destroyed, use any clean plastic bag big enough to cover the microscope. 8. Carry the microscope with both hands, supporting the bottom and holding the arm. Put it back in its box or storage cabinet. C. Caring for a Compound Microscope 1. Check the microscope before and after use. Report any missing or damaged part to your teacher. 2. Use a clean tissue paper or soft cloth like old t-shirt to clean the mechanical parts of the microscope. 3. Prevent liquids, especially acids and alcohol from spilling on any part of the microscope. Always use a cover slip in observing wet mounts. 4. Check for moisture in the eyepiece. This may happen due to prolonged observation of specimens. Wipe with lens paper. 5. Avoid tilting the microscope while observing wet mounts. Water might flow into the mechanical parts of the microscope causing them to rust. Select a chair with suitable height so that both forearms can be rested on the table during observation. 6. Never store the microscopes in a chemical laboratory or any place where there are corrosive fumes. Make sure there are silica get packs inside microscope boxes or storage cabinet to absorb moisture. Activity 1: USING A MICROSCOPE A. Review the techniques in focusing a microscope and complete the following by providing the answers from the box below. Coarse adjustment knob Fine adjustment knob High power objective (HPO) Low power objective (LPO) Body tube Stage Clips Revolving Nose Piece Specimen Eye piece Microscope Mirror Stage Arm Diaphragm I Will Do This
- 8. 8 1. Put the microscope on a flat table top slowly and carefully with its (a) arm facing you. Place it about 17 centimeters or about 6 inches away from the edge of the table. 2. Clean all glass surfaces with lens paper. Start with the eyepiece, then do the objectives and end with the mirror. Use a clean tissue paper or soft cloth like old t-shirt to clean the mechanical parts of the (b) microscope. 3. Look through the (c) eyepiece or ocular with one eye but do not close the other eye. Adjust the (d) mirror so that the light will focus toward the hole of the (e) diaphragm. 4. Place the slide on the (f) stage, hold it firmly with the (g) slide clips on each side. Center the specimen on the slide over the stage window. 5. Watching from the side, carefully lower the body tube using the (h) course adjustment knob until the end of the (i) Low Power Objective (LPO) almost touches the cover slip. 6. To shift to the (j) High Power Objectives (HPO), raise the (k) body tube first using the course adjustment knob. Looking from the side, turn the (l) revolving nosepiece to the High Power Objectives (HPO) in place. Use the (m) fine adjustment knob to lower the High Power Objectives (HPO) till it almost touches the cover slip.
- 9. 9 B. Answer the Analysis Question Supposing you observed the letter “e” under the low power objective then shifted to the high power objective of the compound microscope, then you saw these following images. Analysis Question: 1. What happens as the power of magnification increases? Does the magnification of a specimen increases or decreases? ________________________________________________________________ _____________________________________________________________ 2. Why it is not advisable to use direct sunlight as a light source to view objects under the microscope? Will it permanently damage the eyes? ________________________________________________________________ _____________________________________________________________ 3. Study figure 2: the normal view of letter “e” and viewed under the LPO & HPO. Compare the appearance of the letter ‘e’ when viewed without the microscope to its appearance when viewed under the microscope. ________________________________________________________________ _____________________________________________________________ 4. Which magnification allows you to see the whole letter “e”? Low Power Objective or High Power Objective? ________________________________________________________________ _____________________________________________________________ 5. How should a microscope be carried safely? And stored correctly? ________________________________________________________________ _____________________________________________________________ Letter “e” appears without the microscope Letter “e” appears under the low power objectives Letter “e” appears under the high power objectives Figure 2: Normal view of letter “e” and viewed under the LPO & HPO
- 10. 10 Complete the table by supplying the correct parts, function/s and image of a compound microscope (drawing). Parts Function Image Use to carry the microscope Eyepiece/Ocular Objective Lenses Provides light for the specimen I Practice This
- 11. 11 CALCULATING THE MAGNIFYING POWER OF A MICROSCOPE: Read the selection below and fill in the needed data in order to calculate the magnifying power of a microscope. Use the formula: Ocular x Objective. The Magnifying parts of a microscope enlarges the specimen. These parts includes the Eyepiece or Ocular, located at the top of the body tube where the observer peeps through at the enlarged image of the specimen and magnifies the object ten times (10x). Objective Lenses are located under the revolving nose piece which gather light and magnify the image. The Low Power Objective (LPO) enlarges the specimen 10x. It provides the general view of the specimen. The High Power Objective (HPO) enlarges the specimen 40x. It provides the detailed parts of the specimen. The Scanner-Power Objective Lens enlarges the specimen 4x. The Oil Immersion Objectives (OIO) enlarges the object 100x. From the selection above, record your data in the following table. Provide the magnification power on the spaces provide as discussed above. OCULAR (Magnification) OBJECTIVES (Magnification) LPO HPO OIO Scanner TOTAL MAGNIFICATION Ocular x Objective I Apply This
- 12. 12 I Practice This Module 1 Lesson : Parts and Function of a Compound Microscope and its Manipulation I Will Do This I Apply This Possible Answers to Analysis Question: 1. The magnification also increases. 2. It is not advisable to use direct sunlight as a light source because it can burn the retina of the eyes and cause blindness. 3. The letter “e” without the microscope looks smaller and in correct position. When it was viewed under the LPO the whole letter “e” is seen, it is magnified by 100x and inverted position. In HPO, the image becomes 400x enlarged and only a part of the letter is seen but still in inverted position. 4. Low power objectives allows you to see the whole letter “e”. 5. Microscope should be carried with both hands, one holds the arm and the other supports the base. In storing the microscope, make sure the LPO is in place, body tube is lowered, and stage clips are in place. Rotate the diaphragm until smallest opening in position, Let the mirror stand on its edge with the concave side facing the user. Put inside the plastic bag before putting inside its box or storage cabinet. Answer Key
- 13. 13 References Books: Bernas, V. et al. 2015. Exploring Realms of Science 7. Valenzuela City: JO-ES Eduard C. et al. 2018. Practical Science 7. Makati City: Diwa Madriaga. E et al. 2015. Science Links 7 Science Learner’s Module 7 TAGLAS 7 Microscope: Know My Parts and How I Work TAGLAS 7 LET’S MAP: A Microscope TAGLAS 7 Focus the Microscope Internet: http://staff.concord.org/using_compoundmicroscope https://reviewgamezone.com/mc/candidate/test/?test_id=5133 http://www.sciencequiz.net/newjcscience/jcbiology/cell/mcq/microscope.htm https://mrsancheta.weebly.com/uploads/1/6/1/6/16166098/microscope_worksheet_1.pdf http://www.nobraintoosmall.co.nz/students/juniorscience/Y9/pdfs/Yr9_cellclass_microscope. pdf https://www.pexels.com/photo/focused-biologist-studying-plant-leaf-with-microscope- 3825541/ https://pixabay.com/vectors/microscopy-science-boy-student-148139/ https://www.edb.gov.hk/attachment/en/edu-system/primary-secondary/applicable-to- secondary/moi/support-and-resources/science-education-secondary For inquiries or feedback, please write or call: Department of Education – SDO Bacolod City (Office Address): Rosario-San Juan Sts., Brgy. 14, 6100, Bacolod City Telefax: (034) 704 – 2585 E-mail address: bacolod.city@deped.gov.ph
- 14. 14 Written Assessment No. 1 Worksheet Name: _______________________________ Grade & Section: ___________ MELC: identify parts of the microscope and their functions (S7LT-IIa-1) and to use appropriate techniques in using and manipulating the compound microscope (S7LT- IIb-2). Part I. Read each sentence carefully. Select the letter of the best answer. 1. Which two parts of the light microscope magnify the image of an object? A. Eyepiece and mirror C. Objectives and mirror B. Eyepiece and objectives D. Objectives and diaphragm 2. The parts labeled A and D in the diagram are A. The objective lens and mirror respectively B. The eyepiece and the objective lens respectively C. The mirror and the eye piece respectively D. The objective and the eyepiece respectively 3. Which part will you adjust if the onion cell you are observing under the HPO is not clear? A. part B C. part G B. part C D. part J 4. What is the correct order in which light passes through? A. Slide—eyepiece—objective lens — mirror B. Mirror — objective lens — eyepiece — slide C. Mirror — slide — objective lens — eyepiece D. Mirror — eyepiece — objective lens — slide 5. Which of the following shows “e” seen under the microscope? A. B. C. D. Part II PICTURE SEQUENCING: Study the following pictures on Template 1. Referring to the description, CUT and PASTE the pictures on the boxes below in order to show the correct way of focusing a microscope.
- 15. 15 Focusing a Microscope Reflection Question: How do microscopes help biologists in discovering the natural world? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ 3. Look through the eyepiece with both eyes open and adjust the mirror to capture light. 6. Use the Course adjustment knob to focus under LPO 4. Place the slide on the stage, hold it firmly with the slide clips. 1. Put the Microscope on a flat table 17 cm away from the edge. 2. Incline/tilt the microscope facing light 5. Center the specimen on the slide over the stage window. 7. To shift to HPO, raise the body tube using the course adjustment. Looking from the side, turn the revolving nosepiece to the HPO in place. 8. Look through the eyepiece and adjust the fine adjustment knob until the specimen is seen clearly. . 9. Once done, tilt to its normal position, remove the slide from the stage and position the clip at the center turn the nosepiece to LPO,
- 16. 16 Template No. 1- Focusing a Microscope