General Biology 1
(Senior High School)
Microscope
Cell
Name of Student: ____________________________________
Grade and Section: ____________________ Date: _________
Gubat National High School
S. Y. 2022-2023
Gubat National High School
General Biology 1 Laboratory
GENERAL INSTRUCTION
Science is a hands-on laboratory class. You will be doing laboratory activities, which may
require the use of hazardous chemicals. Safety in the science laboratory is the #1 priority. A list of
rules has been developed and provided to ensure a safe science laboratory. These rules must be
followed at all times.
LABORATORY SAFETY RULES
1. Never play with chemicals and make practical jokes of
any kind in the laboratory.
2. Obey warning signs such as “No Smoking,” “CautionSharp Object,” “Wash Hands First,” and others.
3. Label all chemical containers, showing the name of
the chemical, date, owner’s name, and safety
precautions, if hazardous. Do not remove nor deface
the manufacturer’s label. Read all labels. Heed all
warning signs on the labels.
4. Wear safety gear or industrial-quality safety
spectacles, a laboratory apron or coat (if necessary),
and rubber gloves when handling hazardous
chemicals.
5. Always have another person present (must always be
accompanied by your teacher) or within calling
distance when working in the laboratory.
6. Never performed unauthorized experiments in the
school science laboratory.
7. Report promptly all accidents resulting in injury, proper
damage, or report to proper authorities.
_________________________________________________________
Student’s Signature over Printed Name
Gubat National High School
General Biology 1 Laboratory
Name: _______________________________________________ Group/Student No: _______ Score: ______/30
ACTIVITY No. I-1:
THE COMPOUND MICROSCOPE
The compound microscope serves as a basic tool in your study of Biology. This precision
instrument reveals a world too small to be seen by the naked eye. The microscope makes it possible
to study the structures and functions of microscopic organisms.
I. OBJECTIVES:
At the end of this activity, the students should be able to:
1. identify the parts of a microscope and explain the functions of each part;
2. manipulate the microscope properly;
3. compute for the total magnification of objects observed under the microscope;
4. focus the microscope properly; and
5. prepare a wet mount.
II. MATERIALS: Compound Microscope, Glass slide and Coverslip, Newspaper/ magazine
page, Dropper, Scissors, Water, and forceps/ tweezer
III. PROCEDURE:
A. The Microscope: Its Parts and their Functions
1. Get the microscope from its box or cabinet. Do this by grasping the curved arm
with one hand and supporting the base with the other hand.
2. Carry it to your table or working place. Remember to always use both hands
when carrying the microscope.
3. Put the microscope down gently on the laboratory table with its arm facing you.
4. Wipe with tissue paper the metal parts of the microscope.
5. Locate the eyepiece. Notice also that it is marked with a number and an x.
Know that the eyepiece further magnifies the image of the object that has been
magnified by the objective. If the eyepiece is cloudy or dusty, wipe it gently.
6. Look for the revolving nosepiece. Note that objectives are attached to it.
Usually, the shortest marked 3x, 4x, or 5x is called a scanner. The low-power
objective (LPO) is marked 10x or 12x while the high-power objective (HPO)
is marked 40x, 43x, or 60x. If the longest objective of your microscope is marked
97x or 100x or OIO or the word ‘oil’ is on it, it has an oil immersion objective
(OIO). This objective is used to view bacteria, other protists, and fungi.
7. Find the course adjustment knob. Slowly turn it upwards, then downwards.
Raise the body tube and turn the revolving nosepiece in any direction until the
LPO is back in position. You will know an objective is in position when it clicks.
8. Now, locate the mirror. Position the microscope towards diffused light from the
windows or ceiling light. Look through the eyepiece and with the concave mirror
(with depression) facing up and move it until you see a bright circle of light. (The
bright circle of light is called the field of view of the microscope. Adjust the
position of the mirror so that is it not glaring to the eyes. Practice viewing
through the microscope with both eyes open to reduce eye strain.
9. Locate the diaphragm. While looking into the eyepiece, rotate the diaphragm
to the next opening. Continue to do so until the original opening you used is
back under the hole in the stage.
10. Find the inclination joint. Grasp the arm and slowly pull it towards you. Sit and
try looking through the eyepiece.
B. Making a Wet Mount
1. A specimen is a part or sample of any material for study or examination under
the microscope. Specimens should be small and thin for light to pass through
them.
2. Cut out the smallest letter ‘e’ from a newspaper or a magazine.
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General Biology 1 Laboratory
3. Get the cut out of the letter ‘e’ and mount it on a glass slide. Put a drop of water
and then cover it using a cover slip.
4. Observe the specimen under the LPO. Compare the position of the letter ‘e’ as
seen through the microscope with that seen by the naked eye.
5. Try to move the slide to the right and the left. Observe the direction the image
of the letter ‘e’ goes. What did you notice? __(use the box and space below).
6. Now, move the glass slide forward and backward. Observe the direction in
which the letter ‘e’ goes. What did you notice?__(use the box and space below).
7. Switch the objective to HPO. Describe the changes in size and position of the
image, the brightness or illumination, and the sharpness and clarity of the
image.
8. Draw the image on the two circles below and compute the total magnification.
5. ___________________________________________________________________________________
_____________________________________________________________________________________
6. ___________________________________________________________________________________
_____________________________________________________________________________________
Note: 10 points for practical skills
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General Biology 1 Laboratory
C. Study and label the parts of a compound microscope. Write the parts of the microscope
in the space below.
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General Biology 1 Laboratory
D. GENERALIZATION:
Write your conclusion in this space:
Name: _______________________________________________ Group/Student No: _______ Score: ______/25
ACTIVITY No. I-2:
PLANT AND ANIMAL CELLS
Structurally, plant and animal cells are very similar because they are both eukaryotic cells.
They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic
reticulum, Golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes,
cytosol, and cytoskeletal elements. The functions of these organelles are extremely similar between
the two classes of cells (peroxisomes perform additional complex functions in plant cells having to
do with cellular respiration). However, the few differences that exist between plants and animals are
very significant and reflect a difference in the functions of each cell.
I.
II.
III.
Objectives: At the end of this activity, the students should be able to:
1. prepare a wet mount;
2. describe the cells observed under the microscope;
3. stain a specimen;
4. differentiate plant and animal cells; and
4. identify observable parts of the cell.
Materials: Compound microscope, glass slide and Coverslip, forceps/ tweezer, scalpel,
onion, swab/ toothpick, tissue paper, methylene blue, iodine, and gloves.
Procedure:
A. Preparing Stained Temporary Mount of Onion Peel
1. Prepare the onion scale by following the steps indicated in the picture below.
Use the transparent skin from the inner surface of the onion scale.
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General Biology 1 Laboratory
2. Follow the procedure on how to prepare a wet mount from the previous activity.
3. Examine the onion cells under the LPO and then to HPO.
4. Remove the slide from the stage. You can now stain the onion cells with iodine
solution.
5. Using a dropper, place one or two drops of iodine solution along one edge of
the cover slip. Place a piece of tissue paper on the other edge of the cover slip.
The tissue paper will absorb the water, and the iodine solution spreads under
the cover slip until the whole specimen is covered with stain.
6. Examine the stained onion cells under LPO and HPO.
B. Preparing Stained Temporary Mount of Human Cheek Cells
*Your teacher will give a demonstration on how to collect cheek cell samples.
1. Take a clean cotton swab (or toothpick) and gently scrape the inside of your
mouth.
2. Smear the cotton swab on the center of the glass slide for 2 to 3 seconds.
3. Add a drop of methylene blue solution (CAUTION!) and place a coverslip on
top. Remove any excess solution by allowing the tissue to touch one side of the
coverslip.
4. Place the slide on the microscope, with 4x or 10x objective in position, and find
a cell then view at higher magnification (start with LPO then shift HPO).
5. Also, observe some prepared slides (plant and animal samples)
IV.
Drawing: Draw the onion cell, cheek cell, and other prepared samples as viewed under the
microscope. Label the prominent cell parts visible in each specimen.
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V.
Generalization:
This space is for your conclusion.
Note: 2 points for practical skills
General Biology 1 Laboratory