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Exploring the Microscope: A Hands-on Journey in General Biology, Quizzes of English Literature

De La Salle Araneta University (DLSAU)English Literature

This document provides a comprehensive overview of using a compound microscope in a biology lab. It covers key components, focusing techniques, and important considerations like preventing slide damage and understanding magnification. It also includes student reflections, making it a valuable reference for introductory biology students to develop the skills needed for scientific exploration using this essential tool.

Typology: Quizzes

2022/2023

Uploaded on 03/04/2023

carlos-descanzo
carlos-descanzo 🇵🇭

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EXPERIMENT NO. 1
The Microscope
General Biology 1- Laboratory
Science, Technology, Engineering, and Mathematics
THE MICROSCOPE
INTRODUCTION:
The microscope has revolutionized the way scientists study, identify, classify, and describe very
small members of the kingdom Animalia. It enables research on specimens that otherwise cannot be
seen by the unaided eye. The simple microscope is like a magnifying glass; it is composed of one lens
only. In comparison, the compound microscope has two lenses at opposite ends of a tube. The one
closer to the eye is called the ocular lens, while the one near the specimen is the objective lens. The
present-day microscopes are relatively more sophisticated than their predecessors, particularly the one
invented by Anton Van Leeuwenhoek.
Objectives:
After the exercise, the students should be able to:
• Identify and explain the function of each part of the microscope.
• Describe the features of a microscope.
• Prepare a wet mount.
• Use the lens paper correctly when cleaning the lens.
• Prepare the microscope for visualizing a ready-made slide.
• Focus on the specimen to be studied under the low-power objective (LPO) and high-power
objective (HPO).
• Visualize a specimen under the oil immersion objective (OIO) and remove the oil from the slide
and lens afterward.
• Properly handle, transport, and correctly place the microscope on the lab desk.
• Store the microscope properly.
It is important to develop familiarity with using the microscope. This can be achieved by practice
viewings of a prepared slide of the letter “e,” or any actual specimen. Follow the next ste ps carefully to
improve microscope-viewing skills.
Materials:
• Compound microscope
• Prepared slide of the letter “e” or any
specimen
• Coverslip
• Glass slide
• Lens paper
• Dropper
• Beaker
• Distilled water
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The Microscope General Biology 1 - Laboratory

THE MICROSCOPE

INTRODUCTION:

The microscope has revolutionized the way scientists study, identify, classify, and describe very small members of the kingdom Animalia. It enables research on specimens that otherwise cannot be seen by the unaided eye. The simple microscope is like a magnifying glass; it is composed of one lens only. In comparison, the compound microscope has two lenses at opposite ends of a tube. The one closer to the eye is called the ocular lens, while the one near the specimen is the objective lens. The present-day microscopes are relatively more sophisticated than their predecessors, particularly the one invented by Anton Van Leeuwenhoek. Objectives: After the exercise, the students should be able to:

  • Identify and explain the function of each part of the microscope.
  • Describe the features of a microscope.
  • Prepare a wet mount.
  • Use the lens paper correctly when cleaning the lens.
  • Prepare the microscope for visualizing a ready-made slide.
  • Focus on the specimen to be studied under the low-power objective (LPO) and high-power objective (HPO).
  • Visualize a specimen under the oil immersion objective (OIO) and remove the oil from the slide and lens afterward.
  • Properly handle, transport, and correctly place the microscope on the lab desk.
  • Store the microscope properly. It is important to develop familiarity with using the microscope. This can be achieved by practice viewings of a prepared slide of the letter “e,” or any actual specimen. Follow the next steps carefully to improve microscope-viewing skills. Materials:
  • Compound microscope
  • Prepared slide of the letter “e” or any specimen
  • Coverslip
  • Glass slide
  • Lens paper
  • Dropper
  • Beaker
  • Distilled water

The Microscope General Biology 1 - Laboratory Group name: _______________________ Date: __________________________ Member’s name: Task: Descanzo, Juan Carlos V. Esperancilla, Sean Redik G. Pre-laboratory activity: I. Properly label the parts of the compound microscope. Body Tube Nose Piece Objective Lenses Stage Clips Stage Diaphragm Illuminator Eyepiece/Ocular Lense
Arm Coarse Focus Fine Focus Base

The Microscope General Biology 1 - Laboratory

  1. Place the edge of a cover slip against the water and with a pencil gently lower the cover slip over the letter.
  2. Placing the coverslip in this manner prevents air bubbles from forming underneath the coverslip. Guide Questions:
  3. How could you avoid bubbles in the preparation of wet mounts? ➢ Lack of water could cause the specimen to be crushed or dry out too quickly. Place the cover slip's edge up against the water and slowly lower it over the letter using a pencil or forceps. The cover slip will not produce air bubbles if it is positioned in this manner.
  4. How would you differentiate a bubble from a true specimen? ➢ A bubble is a body of gas. The distinction is that one cannot inspect a bubble to gain essential knowledge about a specific object. Information alone won't be enough. A specimen needs to be more complicated than a straightforward body with many parts. C. Viewing letter “e”
  5. Turn the revolving nosepiece so that the LPO is in position.
  6. Use the coarse adjustment to raise the ocular lens or to lower the stage (in some microscopes) as far down as possible.
  7. Place the slide on the stage and turn the letter “e” in its normal position over the hole in the stage.
  8. Look through the microscope then adjust the diaphragm lever and condenser knob to allow enough light to pass through and make the field bright.

The Microscope General Biology 1 - Laboratory

  1. Turn the coarse adjustment to lower the objective lens as close to the slide as possible but avoid contact between the two.
  2. Look into the microscope and slowly turn the coarse adjustment in the opposite direction so that the objective lens moves away from the slide.
  3. Continue turning until the letter “e” comes into focus. Always remember that the coarse adjustment is utilized only with the LPO.
  4. Use the fine adjustment knob to bring the specimen into perfect focus.
  5. Move the slide a little away from you while observing the specimen in the microscope.
  6. Move the slide up and down, left to right, and note that the inverted image always moves in the opposite direction.
  7. It is time to shift to higher magnification. Turn the nosepiece to move the HPO into the viewing position. Remember that the field of view will be smaller as the magnification increases. When you take a closer look under greater magnification, you will be able to see less and less of the specimen. As the field of view becomes smaller, there will also be a decrease in the depth of field. The thickness of the part of the specimen in focus is larger under low-pressure objective so it is easier to use the coarse focus currently. Only a thin layer is focused on the high magnification, so fine the focus adjustment is critical. The depth of field is also decreased if the iris diaphragm is closed to reduce illumination.
  8. Use the fine adjustment knob to perfectly focus the image. Remember, do not use the coarse adjustment for HPO viewing. The amount of light can also be increased to have a clearer view.
  9. If nothing could be seen in the field, it may mean that the image is not centered properly. In such a case, return to low power, center the image, and then switch back to high power.
  10. Study the details of the letter or the specimen. Move the slide several times to explore different areas.

The Microscope General Biology 1 - Laboratory

  1. How could the breakage of slides be prevented? ➢ Slides could avoid breaking by being kept away from other objects and the microscope's objective lens. Under pressure, the cover glass could shatter or loosen. Take the slide out of the microscope after viewing is finished, then replace it in its holder.
  2. When can you say that the specimen is already in the right position for focusing? ➢ When the object is seen at lower power and centered, the specimen is already in the ideal position for focusing. The microscope should then be changed to the next higher power after that. The specimen is therefore kept central before the magnification power is increased.
  3. Why must you use the fine focus control for HPO? ➢ We must use the fine focus control for HPO to sharpen the focus on the specimen more clearly. It is used with the high-power objective lenses. The course- adjustment knob focuses by moving the lens quickly and is used to find the specimen you are observing.
  4. Why do you have to make sure that the area you wish to study is in the center of the field of view before changing objectives? ➢ Before switching objectives, we must make sure the place we want to investigate is in the center of the field of vision because as we increase the magnification, the field of view's diameter gets progressively narrower. Before changing objectives to enhance the magnification, we must have the object in center.
  5. Why must you turn the nosepiece to the LPO before putting the microscope away? ➢ Before putting the microscope away, we must turn the nosepiece to the LPO in order to protect the high-power objective.

The Microscope General Biology 1 - Laboratory D. How to Compute for Magnification

  1. Locate the numbers on the eyepiece and the low-power objective and fill in the blanks below. Eyepiece magnification x Objective magnification = Total magnification 10x 10 100x
  2. Do the same for high-power objectives. Eyepiece magnification x Objective magnification = Total magnification 10x 40 400 x
  3. Remove the slide and clean it up. Turn off the microscope and wind up the wire so it resembles its original position. Place the low-power objective in place and lower the body tube. Cover the scope with the dust cover. Place the scope back in its original space in the cabinet. Guide questions:
  4. Which objective provides the best resolution of the specimen? ➢ Because this lens is great for examining incredibly minute details within a specimen sample, the high-powered objective lens offers the best resolution of the specimen. This gives us a very clear picture of our specimen (the letter "e") in our provided slide. Additionally, the 400x overall magnification of the high- powered objective lens makes it the ideal tool for spotting tiny details inside the specimen.
  5. Which objective provides a larger magnifying field – the LPO or the HPO? ➢ As I've previously indicated, a higher magnification lens is good for observing minute details, therefore normally a lower magnification objective lens has a greater field of view than a higher magnification objective lens. The magnifying field is therefore greater with the low-powered objective lens.

The Microscope General Biology 1 - Laboratory

DOCUMENTATION:

Direction: Include pictures of your group while doing the activity. Make sure that your faces are included. Put a short label also for descriptions. In this image, I can be seen starting to adhere the sample letter "e" on the glass slide. We placed a drop of water here for the specimen. We then started studying after that. Starting with the low-powered lens on the microscope and observing what we saw. Here we explore how the coarse adjustment knob works. Here, we practice properly moving various objective lenses. We then switched to the next lens, the high-powered lens, and took turns observing what we saw. We had to call Ms. Ang for assistance because we were having trouble focusing our objective on our specimen for this image. However, in the end, we were able to focus our objective, which produced a clear image of our specimen. As we experimented with our microscope, we took pictures of our specimen at various magnifications to see how each objective differed. Our specimen was in scanner mode the last time we took a photo of it. We then summed up our preparation strategies for the worksheet answers.

The Microscope General Biology 1 - Laboratory

SESSION REFLECTION:

Topic: The Microscope Direction: Please answer the question in this template based on your learning experience in this session.

  1. What did you do in this session? (Give a summary of your learning activities). ➢ In this session, my partner and I looked at the components and uses of a microscope. Additionally, we placed the sample specimen (the letter e) on the given slide, and then we used the objectives to look at the sample specimen (scanner, LPO, and HPO). Then, in order to prepare for answering the worksheet's questions, we observed and studied what we saw before generating ideas and information about the experiment.
  2. What did you learn from this session? ➢ During this session, we had the chance to learn more about the microscope. Specifically, its elements and operations. This concept enabled us to comprehend the proper use of the microscope. For instance, by analyzing or studying our sample specimen, we were able to determine the differences between the various microscope objectives. The HPO, for instance, focuses on the specifics of the presented specimen, as can be seen from our discoveries.
  3. How will you apply what you learned? ➢ We may now use all we've learnt here as STEM students in our upcoming experiments. Additionally, we can apply what we've learned to get ready for forthcoming careers like becoming doctors or, preferably, microbiologists. As a result, the knowledge we have acquired will be helpful for all of our future academic endeavors.
  4. What did you like the least in this session? ➢ Our least favorite part of the process was attempting to focus our HPO lens on our specimen. We had trouble visualizing the desired result. We experience a great deal of confusion regarding that, but with Miss Ang's assistance, we ultimately manage to get by. There were no other problems with this activity besides that.