The document summarizes cell theory and the history of cell discovery. It discusses how early scientists like Anton van Leeuwenhoek, Robert Hooke, Matthias Schleiden, Theodor Schwann, and Rudolf Virchow contributed to our understanding of cells. The cell theory states that all living things are composed of cells, cells are the basic unit of structure and function, and all cells come from pre-existing cells. Current cell theory is that all organisms are composed of one or more cells, the cell is the basic unit of life, and cells only arise from other cells.

1. Prepared by: Sir Cee Jae Q. Darunday, LPT
CELLS AND
CELL THEORY

2. CELLS:
• Living things have characteristics that
are common to all.
• For something to be considered "alive",
it means that is made up of the very
tiny structures called cells.
• Cell is considered as the basic unit of
structure and function of all living things.
• A living thing, whether made up of one
cell or many cells, is called an
ORGANISM.

3. CELLS:
Here are few of the different kinds of cells
according to role:
• •Epithelial cells - These are the cells
that protect the surface of the body, as
well as cover the organs and body
cavities within it.
• • Blood cells - These are the cells that
carry the nutrients and oxygen
throughout the body, and remove
carbon dioxide.
Cells are very crucial in the growth, development, and daily maintenance of the
body.

4. CELL THEORY
• The cell theory is called the foundation
of modern biology.
• It served as the guiding paradigm to
succeeding scientists who established
hallmarks in biology.

5. CELL THEORY
Let us trace the discovery of the cell through the
scientists who contributed their own theories.
• Anton van Leeuwenhoek
⚬ He is a Dutch shopkeeper who had great
skill in crafting lenses. In the 1600s, he was
able to observe the movements of protists,
or organisms that are single-celled.
⚬ He also observed the motion of the sperm
cell, which he called "animalcules." He was
the one who discovered bacteria and
protozoa in the 1670s.

6. CELL THEORY
Let us trace the discovery of the cell through the
scientists who contributed their own theories.
• Robert Hooke
⚬ He is an experimental scientist who
observed a cork tissue through a lens, and
saw box-like structures.
⚬ He coined the term "cell" for these
framework.
⚬ He published the book, Micrographia, which
became significant through his detailed
observations and drawings.

7. CELL THEORY
Let us trace the discovery of the cell through the scientists who
contributed their own theories.
• Matthias Schleiden and Theodor Schwann
⚬ They studied tissues and had an idea that all living
things are composed of cells. They proposed the
unified cell theory which states that:
￭ the cell is the unit of structure, physiology, and
organization in living things;
￭ the cell retains a dual existence as a distinct entity
and a building block in the construction of
organisms; and
￭ cells form by free-cell formation or spontaneous
generation.

8. Let us trace the discovery of the cell through the
scientists who contributed their own theories.
• Rudolf Virchow
⚬ He made an important contribution to the
theory of Schleiden and Schwann.
⚬ 'Through his studies, he corrected the third
conclusion, stating the dictum "omnis cellula
e cellula," which means that living cells come
from pre-existing living cells and there is no
spontaneous creation of cells from nonliving
matter.
CELL THEORY

9. 'THROUGH THE CELL THEORIES PROPOSED BY THE EARLY SCIENTISTS-THAT ALL LIVING
CHINGS ARE COMPOSED OF CELLS AND THAT ALL CELLS ARISE FROM OTHER CELLS-
CAME THE BASIS FOR A WORKING DEFINITION OF LIVING THINGS.
CELL & CELL THEORY
• All known living things are made up of cells.
• The cell is the structural and functional unit of all
living things.
• All cells come from pre-existing cells by division.
• Cells contain hereditary information that is passed
from cell to cell during cell division.
• All cells are basically the same in chemical
composition.
• All energy flow of life occurs within cells.

10. Current Cell Theory:
CELL & CELL THEORY
• All living organisms are composed of one or more
cells.
• A cell is the basic structural and functional unit of
living organisms.
• All cells arise from pre-existing cells.

11. Don't hesitate to ask any
questions!
THANK YOU FOR
LISTENING!