education presentation

1. Quarter Two
SCIENCE 7

2. • Identify parts of the microscope and their functions. (S7LT-IIa-1)
At the end of the lesson, you should be able to:
a. name the scientists who have contributed to the historical
development of microscopes;
b. appreciate the contributions of those scientists to its development;
c. identify the parts and functions of a compound microscope; and
d. suggest ways on how to properly handle a compound microscope.
Module 1: Parts and Functions of a Compound
Microscope

3. Word Bank
The following terms used in this module are defined as follows:
• Concave Mirror – mirror with depression; mirror that curves inward
• Magnification – process of causing an image to appear larger than it
really is.
• Microscopy – the science of investigating objects too small to be seen
by our unaided eyes with the use of microscope
• Ocular – the eyepiece
• Specimen - object or sample being observed under the microscope

4. Direction: Read each statement carefully. Choose the letter
of the correct answer.
1. Which part of the microscope will you use to get a detailed view of
the specimen?
a.coarse adjustment knob b. eyepiece/ ocular lens
c. high power objective d. low power objective
2. Who among the scientist(s) listed below started experimenting
through the use of lenses and made a very important invention – a
compound microscope?
a.Anton van Leeuwenhoek b. Robert Hooke
c. Zack and Hana Jansen d. Zacharias and Hans Jansen

5. 3. Which part will you manipulate to switch the objectives from
LPO to HPO?
a. adjustment knobs b. revolving nosepiece
c. inclination joint d. body tube
4. Which instrument listed below is BEST used by scientists in
viewing samples or objects that are invisible or slightly visible to
the naked eye?
a. lens b. glass c. magnifying glass d. microscope
5. The science of investigating objects invisible to our naked eyes
with the use of microscope is _____.
a. microscopy b. cytology c. anatomy d. microbiology

10. • A compound microscope is a type of microscope that uses visible light
to illumine the object being observed.
• It consists of two optical parts, the ocular lens in the eyepiece and the
objective lenses.
• The eyepiece lens commonly magnifies 10x. This means that any
object you will see with this lens will be magnified 10 times.
• Usually, a compound microscope contains two objective lenses. They
are the low power objective (LPO) and high-power objective (HPO)
lenses with 10x and 40x magnification, respectively.
• Magnification is the process of causing an image to appear larger than
it really is.

11. The parts of a Compound Microscope can be
categorized into three, namely:
a. ILLUMINATING PARTS are the parts responsible for the supply of
light. These are the mirror, diaphragm and the ocular/ eyepiece.
b. MAGNIFYING PARTS are the parts that enlarge the object once
seen under the microscope. They are the ocular lens and the
objective lenses. The objective lenses are the scanner, the low
power objective (LPO) and the high- power objective (HPO). Under
LPO, the object being viewed shows the entire outline of the
specimen. On the other hand, once HPO is used, the object being
viewed shows the detailed structure of the specimen.

12. There are three types of objectives.
These are:
• Scanner - usually marked 4x, combined with the eyepiece lens, will
provide the lowest magnification power;
• Low power objective- usually marked 10x, most helpful in analyzing
glass slide samples; and
• High power objective- longer than the LPO and usually marked 40x or
60x, used to focus on a specific part of the specimen.
c. MECHANICAL PARTS are responsible to hold and support the
structural components of the microscope. These are the base, arm,
body tube, stage, stage clips, adjustment screws and the revolving
nosepiece.

13. PARTS AND FUNCTIONS OF A COMPOUND MICROSCOPE
PARTS FUNCTIONS
1. EYEPIECE/ OCULAR LENS It contains the magnifying lens where you look through which usually provides a 10x or
a 15x magnification. It allows viewer to see the magnified image of the specimen.
2. BODY TUBE It connects the eyepiece to the revolving nosepiece with the objectives
3. ARM It supports the body tube and connects it to the base. It is where the microscope is
held.
4. MIRROR It reflects the light upward through the diaphragm, the specimen, and the lenses. Look
through the eyepiece and with the concave mirror (with depression) facing up, move it
until you see a bright circle of light. The bright circle of light is called the field of view of
the microscope.
5. DIAPHRAGM It regulates the amount of light that goes into the body tube and reaches the specimen.
The size of the openings differs. The amount of light reflected also changes where the
bigger the opening, the greater is the amount of light reflected.
STAGE It supports the slide containing the specimen being viewed. The slide mounted on the
stage can be moved from side to side until the specimen comes into view.
STAGE CLIP It holds the slide in plac

14. PARTS FUNCTIONS
REVOLVING NOSEPIECE It holds the objective lens and facilitates the changing of the desired objective to its
position. It is movable hence it can rotate the objective lenses depending on the
magnification power of the lens that you are going to use.
COARSE ADJUSTMENT KNOB It moves the tube and lower power objective (LPO) lens closer or farther away from the
stage to view the image of the specimen. Turning the coarse adjustment knob upwards and
downwards raises and lowers the body tube with the objectives, respectively. It also
focuses or brings out the object to be observed.
FINE ADJUSTMENT KNOB It brings an image of the specimen into fine focus showing the detailed parts of the
specimen while using the high- power objective (HPO) lens. It is being turned slowly until
the specimen comes into view.
OBJECTIVE LENS These are the scanner, Low Power Objective (LPO) and High-Power Objective (HPO) that
magnify the image of the specimen. The objectives are attached to the revolving
nosepiece. The low power objective (LPO) is marked with either 10x or 15x and shorter in
length. The high- power objective (HPO) is longer and is usually marked 40x.The x
represents how many times the object being viewed under the microscope was magnified.
For example, 10x means: the object was magnified 10 times its size.
BASE It provides support and serves as a stand of the microscope.
INCLINATION JOINT It is the joint that connects the arm and the base of the microscope. It enables the
microscope to be tilted to view the specimen while the viewer is sitting

15. The following are some reminders and cautions to
be observed in handling the microscope.
1. It is important to lift the microscope from the cabinet with the use of two
hands. One hand should grab the microscope by its arm and the other
hand should be placed under the base of the microscope to ensure the
microscope is firmly held.
2. View through the microscopes using both eyes open. This will reduce
eyestrain.
3. CAUTION: Never use direct sunlight as a light source. Direct sunlight can
permanently damage the retina of the eye.
4. CAUTION: Glass slides are fragile. Make sure the lens does not hit the
slide.

16. 5. Tilting of the microscope allows one to do observations while sitting
down. This is however, only done when materials observed do not
contain liquid like water.
6. It is important to clean the ocular lens and the objective lens each lab
period before and after use. Only use lens paper in cleaning the lenses
of the eyepiece and the objectives. Do not use paper towels, since
they will scratch the lens.
7. Use clean soft cloth or tissue paper to clean the mechanical parts of
the microscope.
8. Do not store the microscope in a chemical laboratory. Instead, store it
inside microscope box with silica gel inside.

17. Write TRUE if the sentence is correct and FALSE if it is incorrect.
_________ 1. The revolving nosepiece is used to switch from one objective to another.
_________ 2. Any cleaning material may be used to clean the lenses of the microscope.
_________ 3. The microscope is used to magnify objects far from you.
_________ 4. The use of direct sunlight to brighten the field being magnified is
advisable.
_________ 5. The mirror provides the field of view when looking through the
microscope.
_________ 6. The arm is where you hold the microscope.
_________ 7. To ensure the safety of the microscope, both hands should be used.
_________ 8. The slide can be moved to focus certain parts of the specimen.
_________ 9. It is advised to look through the eyepiece with both eyes open to avoid
eyestrain.
________ 10. Coarse adjustment knob is used for high-power objective (HPO).

18. • Prepare a wet mount;
• Make a DIY (Do It Yourself) microscope;
• Describe the image produced under different objectives;
• Compare the images produced;
• Solve for the total magnification of the specimen under different
objectives; and
• Familiarize with some practices in taking care of the microscope.
Focus specimen using the compound microscope (S7LT-IIb-2)

19. Word Bank
• Enlarged – the image is larger than the object
• Glycerin- also known as glycerol, a natural compound derived from vegetable oils or animal fat; helps the
specimen from drying out.
• Immersion Oil- oil placed on a slide of the material to be examined which results in higher brightness at high
magnification and high image resolution
• Inverted – the image is upside down
• Magnification- a measure of the ability of a lens to magnify.
• Permanent Mount- a mount that uses a mounting medium which turns solid.
• Real image – the initial image of the specimen formed by the objective
• Reversed – the image formed is switched from left to right
• Specimen - a part or sample of any material e.g.plant, animal, paper, or mineral, for study or examination
under the microscope. It should be small and thin for light to pass through it.
• Virtual Image – the second image of the specimen once the real image is projected to the plane of the
eyepiece.
• Wet Mount- a glass slide holding a specimen suspended in a drop of liquid for microscopic examination.

20. Directions: Identify what is asked or described in each
item. Encircle the letter corresponding to your answer.
1. Which of the following refers to the type of mount that uses liquid
during its preparation? a. dry mount b. pet mount c. prepared
mount d. none of the above
2. Which part of the microscope is responsible in enlarging the
specimen? a. Magnifying parts b. Illuminating parts c. Mechanical
parts d. Supporting parts
3. Which of the following statement best describes magnification?
a. It is the ability of a lens to enlarge specimen.
b. It is enlarging image of a specimen.
c. It is displaying details of enlarged specimen.
d. It is separating image details.

21. 4. What is the position of the image produced by the microscope with
respect to the original position of the specimen?
a. upright c. inverted b. landscape d. portrait
5 What is the formula in computing the total magnification of the
image in a compound microscope?
a. total magnification of the specimen = (magnification of the
eyepiece) x (magnification of the objective)
b. b. total magnification of the specimen = (magnification of the
eyepiece) / (magnification of the objective)
c. c. total magnification of the objective = (magnification of the
eyepiece) x (magnification of Specimen)
d. d. total magnification of objective = (magnification of the eyepiece)
/ (magnification of the specimen)

33. LIVING THINGS AND THEIR ENVIRONMENT

34. Module 3. From Cell to Biosphere
Describe the different levels of biological organization from cell to
biosphere. (S7LT-IIc-3)
• Identify the different levels of biological organization;
• Describe the different levels of biological organization from cell to
biosphere;
• Determine the relationship of the different levels of biological
organization; and
• Give example/s of the levels of biological organization.

35. Word Bank
• Biology - defined as the science of life.
• Levels of Biological Organization - are structures in nature, usually
defined by part-whole relationships, with things at higher levels being
composed of things at the next lower level
• Multicellular – an organism having or consisting of many cells
• Unicellular – also known as single-celled organism, that consisting of a
single cell

36. Try This!
1. What is the basic unit of life?
a. organ b. organ system c. cell d. tissue
2. Heart, liver, stomach, and skin are examples of ____________.
a. organs b. tissues c. atoms d. molecules
3. In an organism, what do you call the system that is composed of a group of organs that cooperate
in order to carry out a particular function?
a. Tissue b. Organ c. Organism d. Organ system
4. Which of the following differentiates organs from tissues?
a. Organs and tissues are made up of cells.
b. Tissues make up organs; cells make up tissues.
c. Organs make up tissues; tissues make up organs.
d. Organs and tissues make up an organ system.
5. What is the most complex level of biological organization?
a. Community b. Biosphere c. Population d. Organism

37. Direction: Rearrange the letters in the correct order to form a word associated to
levels of biological organization. Use the given picture as clue.
1. LELC - ______________ 2. IOBSEPRHE - ______________

38. 3. SITUESS - ___________ 4. METYSSOCE - __________
5. ORNAG - _________ 6. TYUNIMCOM - ___________

39. 7. GANOR SYSTEM - ______________
8. TIONALUPOP - ________________
9. MISGANROS - ____________

40. Keep in Mind!
• Cell
A cell is the basic unit of life. There are two kinds of cells: plant cells, which
have a rigid cell wall made of cellulose molecules, and animal cells, which have
flexible cell membranes.
• Tissue
Tissue is made of cells that work together to perform a certain task. Muscle
tissue, connective tissue, and neural tissue are some types of tissue. Histologists
are an example of biologists who work at this level.
• Organ
An organ is a system of tissues that work together on a larger scale to do
certain jobs within an animal's body. Examples of organs are the brain, heart, and
lungs. Anatomy is an example of biology especially concerned with this level.

41. • Organ System
An organ system is a group of organs that work together to
perform specific bodily functions. The respiratory system, for example,
uses the lungs, airways and respiratory muscles to inhale oxygen and
release carbon dioxide in animals. Physiologists study the function of
parts of the body as they work together.
• Organism
An organism is a recognizable, self-contained individual.
Organisms can be unicellular organisms such as bacteria or amoebae,
or multi-cellular organisms comprised of organs and organ systems. A
human being is an example of a multi-cellular organism.
• Population
A population is a group of multiple organisms of the same
species within a specific area. For example, a pride of lions in Kenya,
Africa, is a population.

42. • Community
A community consists of all the different species within a certain area.
The population of lions in Kenya, plus the populations of gazelles, giraffes,
elephants, dung beetles, and all other species in that area, add up to a
community.
• Ecosystem
An ecosystem is made up of all the communities in a certain area, as
well as all the non-living, physical components of the environment. Rocks,
water and dirt are a part of an ecosystem. Ecologists may study populations,
communities, or whole ecosystems.
• Biosphere
The biosphere is all of the ecosystems on Earth added together. Every
animal, plant, bacteria, rock, and molecule is a part of the Earth's biosphere.
Non-biologists, such as meteorologists and geologists, may join biologists to
answer questions at this level of biology organization.

43. Directions: Identify what is asked or described in each item then write the
letter of the correct answer.
1. Which is the correct sequence from simplest to complex levels of
biological organization?
a. Cell-tissue-organs-organsystem-biosphere-population-community-
ecosystemorganism
b. b. Cell-tissue-organs-organsystem-organism-community-ecosystem-
populationbiosphere
c. c. Cell-tissue-organs-organsystem-organism-population-community-
ecosystembiosphere
d. d. Cell-tissue-organs-organsystem-organism-community-population-
ecosystembiosphere

44. 2. What is the simplest level of biological organization?
a. Tissue b. Organ c. Organism d. Cell
3. Animals, plants, fungi, and algae are examples of
a. Tissue b. Cell c. Organisms d. Organs
4. When many organ systems work together it can form
a. Cells b. Organism c. Organ d. Organ
system
5. It is a life-supporting stratum of the earth’s surface, covering a
few kilometres into the atmosphere to the deep-sea vents of the
ocean.
a. Population b. Biosphere c. Community d. Ecosystem

45. Differentiate plant and animal cells according to presence or absence of
certain organelles (S7LT-IId-4)
At the end of the lesson, you should be able to:
• identify the parts of animal and plant cell;
• describe the parts and function of each cell part; and
• compare and contrast plant and animal cell.
M0dule 4- Plant and Animal Cell

47. WORD BANK
The following terms used in this module are defined as follows:
• Cell Membrane – a protective layer surrounding the cell that controls
what enters and leaves the cell. (both plant and animal cell have this)
• Cell wall – a stiff outer layer that surrounds a plant cell, protects it,
and gives it its shape
• Chloroplasts – organelles, found only in plant cells, in which sugar is
made during photosynthesis
• Chromosomes – structures in the nucleus that contain an organism’s
genetic information and regulate the cell’s activities

48. • Cytoplasm – a clear, jellylike substance that holds the organelles in place
• DNA – the abbreviation for deoxyribonucleic acid, the chemical that
provides detailed instructions for cells
• Mitochondrion – a bean shaped organelle that goes through a process
which releases energy in order for the cell to complete all its activities
• Nucleus – the control center of a cell that directs the cell’s activities
• Organelle – the structure in plant and animal cells that perform specific
functions
• Photosynthesis – is the process in which plant cells convert water and
carbon dioxide in the presence of sunlight to sugar and water, releasing
oxygen.

68. Direction: Identify what is asked or described in each
item then write the letter of the correct answer.
1. Which of the following is not found inside the cell?
a. endoplasmic reticulum b. cilia c. golgi apparatus d. nucleus
2. What part of the cell refers to a membrane-bound compartment
containing fluid and is found in the cytoplasm?
a. lysosomes b. ribosomes c. mitochondrion d. vacuole
3. If the chloroplasts of a plant cell are damaged, which will it be unable to
do?
a. Protect the cell c. Excrete waste materials
b. Make food for the cell d. Give instruction for the cell to reproduce

69. • 4. The main function of the cell wall is to:
a. Support and protect the cell
b. Store DNA
c. Help the cell move
d. Direct the activities
5. Which of the following lists of structures can be found in both plant and
animal cell?
a. mitochondria, cytoplasm, cell wall, vacuole, cell membrane
b. cell membrane, nucleus, ribosomes, golgi bodies, cytoplasm
c. cell wall, mitochondria, cytoplasm, chloroplast, cell membrane
d. vacuole, lysosome, centriole, cell wall, cell membrane