This document provides an overview of cell theory and its historical development. It begins with learning outcomes about explaining cell theory postulates and creating 3D cell models. It then discusses the key figures in developing cell theory from Hooke's discovery of cells in 1665 to modern cell theory. Modern cell theory states that all living things are composed of cells, cells are the basic functional units, cells come only from pre-existing cells, cells carry genetic material passed during cell division, and cells have the same basic structure and use biochemistry to generate energy.

1. Week 1 Lesson 1:
Cell Theory

2. Learning Outcomes
Intended
Learning
Outcome
The students will create a 3D model of the cell that
describes the structure of its type with correct label,
and accurate representation of its parts.
Most
Essential
Learning
Competanc
y
The students will explain the postulates of the cell
theory.

3. Table of Contents
Biological
Organization
Concept of
Life
Cell
Theory

4. Kahoot!
https://create.kahoot.it/share/concept-of-life-and-
cell-theory/2b38e3a5-faba-49b0-992c-
b0eb07d70f4e

5. Biological
Organization
01

6. Levels of Biological
Organization
“Whenever you feel sad just remember
there are billions of cells in your body
and all they care about is you.”
~ awko_dolphin, pinterest

7. CELL TISSUE ORGAN
ORGAN
SYSTEM
ORGANISM
Levels of Biological
Organization Levels of
Organization

8.  Basic and smallest unit of life and
often called the “building blocks of
life”.
 Cytology is the study of cell. Cyto
means cell and logy comes from the
Greek word logus meaning to study.

9. Tissue
 Many cells working together
form tissue. The cells
involved are specialized to
cooperate with each other to
accomplish one common
goal.
9

10. Organ
 When there are layers of
tissue working together, they
form an organ. All animals
contain organs as well as
plants.
10

11. Organ
System
 When organs work together,
they form organ systems.
Organ systems keep the
body regulated and in a
stable state. These systems
often work together and
rarely work in isolation.
11

12. Organism
 Organisms or can be called
as species are technically
any form that can carry out
its own functions such as
take material in and push
material out. For the
purposes of the level of
organization, organisms are
made up of many organ
systems working together.
12

13. Concept of
Life
02

14. Theories about the Origin of Life
Special
Creation
Extraterrestrial
Origin
Spontaneous
Origin
Life forms may have
been put on earth by
supernatural or
divine forces.
Life may not have originated
on earth at all; instead, life may
have infected earth from some
other planet
Life may have evolved from
inanimate matter, as
associations among molecules
became more and more
complex.

15. How Can You
Say that a
thing has life?

16. 1. All organisms use ENERGY.
A series of processes that
control how organism
creates and uses energy.

17. 2. All organisms maintain a stable internal environment
(HOMEOSTASIS).
Homeostasis refers to the
body's need to reach and
maintain a certain state of
equilibrium.

18. 3. All organisms DETECT and RESPOND to select external
STIMULI. (SENSITIVITY)

19. 4. All organisms can engage in MOVEMENT (which
may occur internally, or even at the cellular level).

20. 5. All organisms show GROWTH and DEVELOPMENT;
that is, specialization of cells or structures. (Even
unicellular organisms show a tiny amount of growth,
and single cells repair and use materials from the
environment to replace internal structures as needed.)

21. 6. All organisms REPRODUCE. (Even if an individual
can’t reproduce, its species can.) In addition, an
individual’s cells are constantly reproducing
themselves.
Asexual Reproduction

22. 7. All organisms have NUCLEIC ACID as the hereditary
molecule. (HEREDITY AND VARIATION)

23. 8. All organisms show ADAPTATION, which occurs at
the individual level and is tightly related to homeostasis.
A change or the process
of change by which an
organism or species
becomes better suited to
its environment:
ADAPTATION

24. 9. All organisms are made of one or more CELLS.

25. 10. All organisms exhibit COMPLEX ORGANIZATION,
grouping molecules together to form cells; at a higher
level, cells are organized into tissues, organs, and
organ systems.

26. 11. All organisms exhibit EVOLUTION over
time due to mutation and natural selection
(which operates at the species level).

27. Historical
Development of
the Concept of
Cell and Cell
Theory
03

28. ▸ Before 330+ years ago, there was no knowledge of
cells. Cells were too small to be seen. But with the
invention of the microscope, an entirely new world was
discovered, where very large objects like humans are in
fact made up of billions of tiny individual pieces called
cells.
Before we know it:

29. Zacharias
Janssen
▸ 1597 Zacharias Janssen
invented the compound
microscope together with his
father, Hans Janssen.

30. Robert
Hooke
▸ Hooke was looking at dead
plant cell walls that belonged
to a piece of cork. He termed
this cell.
▸ Hooke's discovery help paved
the way to the rejection of
spontaneous generation by
demolishing the idea that living
things came out of nothing or
nonliving things.
▸ Father of Microscopy.
1665, Robert Hooke made the revolutionary discovery
of the cell.

31. Anton van
Leeuwenhoek
▸ Leeuwenhoek crafted specific
lenses for a microscope he used
to observe small organisms from a
lake as well as the stinger of bees.
He called it animalcules.
▸ This scientist's discovery helped
lead to the rejection of spontaneous
generation through supporting the
notion that living things must come
from somewhere and must be made
out of some "entity" instead of
randomly appearing out of thin air or
abiotic factors.
1673, Anton van Leeuwenhoek made an enormous
contribution to the cell theory. Father of Microbiology.

32. Robert
Brown
▸ Discovered the nucleus
from the orchid which is the
center of a cell that
contains the genetic
material of an individual.
(1830)
1833, Robert Brown an English botanist

33. Matthias
Schleiden
▸ He proposed that cells were a
fundamental unit of life and that all
living things have them.
▸ He stated that all plants are made
of cells.
▸ This discovery helped debunk the
theory of spontaneous generation
by supplying the public with the
fact that all for something to be
alive, it must be made up of cells. 1838, Matthias Jacob Schleiden analyze plants and their
cells through a compound microscope.

34. Theodore
Schwann
▸ Schwann went on to analyze
animal tissue and thus, the fact
that all living things have cells
was permanently ingrained into
the cell theory.
▸ He stated that all animals are
made up of cells.
▸ This discovery helped reject the
theory of spontaneous generation
by encouraging that living things
don't appear out of non- living
things.
1839, Theodore Schwann made the contribution
in animal cell.

35. Rudolf
Virchow
▸ supported the claim that all cells
arise from other cells
(reproduction).
▸ This scientist's contribution
dispelled the theory of
spontaneous generation by
proving that living things do not
come from nothing.
It was around 1855 when Virchow completed the
third statement

36. Louis
Pasteur
▸ Cells are products of other
cells.
▸ This scientist's discovery
helped lead to the rejection of
the theory of spontaneous
generation by proving that
living things are products of
cells, which are living things.
1850, Louis Pasteur, experiment showed that cell only
be formed from pre-existing cells.

37. Swine Neck Experiment
● Pasteur boiled a meat broth in a
flask that had a long neck that
curved downward, like a goose.
The idea was that the bend in the
neck prevented falling particles
from reaching the broth, while still
allowing the free flow of air. The
flask remained free of growth for an
extended period. When the flask
was turned so that particles could
fall down the bends, the broth
37

38. Robert
Koch
▸ Developed the technique of
staining bacteria to improve
the visibility under the
microscope.
Without stain With stain

39. Max Knoll
and Ernest
Ruska
▸ Invented the electron
microscope in 1931.

40. The Three Tenets of the Cell
Theory
40
03
02
01 All living things are composed of one or more cells.
Cells are the basic units of structure and function
in an organism.
Cells come only from the reproduction of pre-existing
cells.

41. Modern Cell Theory
41
06
05
04
Cells carry genetic material which is passed from cell
to cell during cell division.
Cells are basically the same in structure and
chemical composition.
Energy flow (biochemical process) occurs within cells.

42. Characteristics of Life
Theories about Life
• Cell
• Tissue
• Organ
• Organ System
• Organism
Levels of
Biological
Organization
Learning
Summary
Cell Biologist &
Theorist
• Special Creation
• Extraterrestrial
Origin
• Spontaneous
Origin
• Energy
• Homeostasis
• Sensitivity
• Movement
• Reproduction
• Heredity and Variation
• Adaptation
• Cells
• Complex Organization
• Growth and
Development
• Evolution
• Zacharias Janssen
• Robert Hooke
• Anton van
Leeuwenhoek
• Robert Brown
• Matthias Schleiden
• Theodore Schwann
• Rudolf Virchow
• Louis Pasteur
• Robert Koch
• Max Knoll and Ernest
Modern Cell
Theory
• All living things are composed of one or more cells.
• Cells are the basic units of structure and function in
an organism.
• Cells come only from the reproduction of pre-existing
cells.
• Cells carry genetic material which is passed from cell
to cell during cell division.
• Cells are basically the same in structure and chemical
composition.
• Energy flow (biochemical process) occurs within
cells.

43. Proponents Contributions
1. Robert Brown a. Animals are composed of cells.
2. Robert Koch b. Developed the staining technique.
3. Robert Hooke c. Invented the compound microscope
4. Theodore Schwann d. First to observed cells in a piece of cork under the
microscope.
5. Matthias Schleiden e. First to do an experiment that rejects spontaneous
generation.
6. Louis Pasteur f. Invented the electron microscope.
7. Zacharias and Hans Janssen g. First to observed small motive organisms under the
microscope.
8. Max Knoll and Ernest Ruska h. Discovered the nucleus.
9. Anton van Leeuwenhoek i. Plants are made up of cells.
10. Rudolf Virchow j. He stated that cells arise from pre-existing cells.
Direction: Match Column A with Column B. Write the letter of your answer before each number.

44. Asynchronous task will be posted on your
LMS. Make sure that you check it during
your scheduled time. Clicking
thumbs up button signifies
your attendance!!!

45. Thanks!!!
End of
Lesson
Prepared by
Jeffrey Alemania, RN LPT