Take a look on the discovery of the basic unit of life - Cell.

1. The Cell and Its Beginning
By: Jayson I. Gula
Faculty, Hua Siong College of Iloilo

2. Think about this!
What makes these living things
alike?

3. They are all made up of
cells!

4. Cells are the basic units of structure and
function in living things.

5. Take a look
In fact, one
square centimeter
of your skin’s
surface contains
over 100,000

6. Earliest Microscopic
Observations
 King Charles II of England
(1661)
 Commissioned a
microscopic examination of
the natural world.
 Focus on Insect Anatomy

7.  Robert Hooke (1635 – 1703)
 In 1663, Hooke observed the structure
of a thin slice of cork using a
compound microscope that he built
himself.
 Described it as having a perforated
and porous surface like honeycomb.
 He called it as cellulae.

11.  Anton Van Leeuwenhoek (1632-1723)
 Invented a simple microscope with one
lens.
 He was the first to observe living cells.
 Leeuwenhoek used his microscope to
look at pond water. He was surprised
to see one-celled organisms, which he
called animacules, meaning little
animals.

13. Schleiden and Schwann
 In 1838, Matthias Schleiden, a
German scientist concluded
that all plants are made of
cells.
 The next year, another
German scientist, Theodor
Schwann concluded that all
animals are also made of

14. Rudolf Virchow
 In 1855, a German doctor, Rudolf
Virchow proposed that new cells are
formed only from existing cells.
 “All cells come from cells” wrote
Virchow.

15. THE CELL THEORY

16. The Cell Theory
All organisms are composed of one or
more cells, within which processes of
life occurs.
Cells are the smallest and basic units of
structure and function in organisms.
Cells arise only from previously existing
cells.

17. ORGANIC CHEMICAL EVOLUTION
 The first forms of true
living cells have evolved
from protocells.