The document discusses the history and development of the microscope from its earliest forms to modern compound microscopes. It describes key figures like Anton van Leeuwenhoek, who was the first to observe and describe microorganisms, and Robert Hooke, who first observed and named plant and animal cells after viewing cork tissue under a microscope. The document also outlines the basic parts and functions of simple microscopes, which use a single lens, and compound microscopes, which use multiple lenses to provide higher magnification. Compound microscopes are described as having illuminating, magnifying, and mechanical parts that work together to provide clear, enlarged views of microscopic specimens.

1. The
Microscope
and Its
Historical
Development
Science Links 7 Revised
Edition pp. 112-115
BOHOL INTERNATIONAL
LEARNING COLLEGE

2. Microscope
+ It is a precision instrument
and the number one tool
being used by biologists in
conducting biological
researches and in
studying objects or
organisms that are
invisible or slightly visible
to the naked eye.

3. Zaccharias Janssen
+ In 1950s, he started experimenting
using lenses with his brother Hans
Janssen.
+ Janssen brothers made a very
important discovery, a compound
microscope which uses two or more
lenses.

4. Anton Van
Leeuwenhoek
+ Father of Microscopy
+ He was the first to discover bacteria,
yeasts, and red blood cells.
+ He was able to describe colonies of
protozoans teeming in a
rainwater, which is called
animalcules.

5. Robert Hooke
• An Englishman Scientists and
architect, who first visualize micro-
organism.
• He discovered tiny compartments in
a thin slice of cork. He called these
compartments "cells".

6. Types of Microscope
Simple microscope Compound Microscope

7. Simple Microscope
• Simple microscopes are
composed of one lens and
provide relatively low magnifying
powers.
• A good example of a simple
microscope is a magnifying glass.

8. Compound Microscope
• Compound microscopes are
composed of two or more lenses
that provide powerful magnification.
• Compound Light Microscope ae
categorized into three: illuminating
parts, magnifying parts, and
mechanical parts.

10. Illuminating Parts
• Illuminating Parts are the parts that provide light. Light is important
for the object/specimen to be seen.
• The light may come from two sources: natural source (reflected
sunlight) or artificial source (light bulb).
Mirror – reflects the light from the source to the specimen
Diaphragm – regulates the amount of light striking the specimen
Ocular eyepiece – focuses light to the eye;
Objective – gathers light

11. Magnifying Parts
• Magnifying parts are the parts that enlarge object or specimen.
• Ocular lenses – enlarge the object to six times 6x or ten times 10x
• Objective lenses;
 Low Power Objectives (LPO) locates and enlarges the specimen 10x
 High Power Objective (HPO) enlarges the specimen 40x,43x, or 45x
 Oil Immersion Objective (OIO) enlarges the object 100x

12. Mechanical Parts
• Mechanical parts are the parts of the microscope that support,
adjust, connect, and move other parts.
Base – supports the entire weight of the microscope
Arm – supports the body tube and the part is held when the microscope is carried from
one place to another.
Body tube – connects the lenses of the objectives and the ocular.
Stage – holds the slide while the stage clips hold the slide firmly in place.
Adjustment screws – move the objectives to bring the specimen into focus.
Coarse adjustment screw - is the large knob that moves the body tube faster to focus the
specimen.
Fine adjustment screw – is the smaller knob that is used as to get sharp focus of the specimen
being viewed.
Revolving nosepiece – is the rotating disc that holds the different objectives and allows
for the shifting from one objective to the next.

13. How are
Microscopes
Useful?

14. End