3. ROBERT
HOOKE(1635-
1703)
In 1665, an English scientist, Robert Hooke examined a
thin size of cork under the microscope. He observed that the
piece of cork was composed of many tiny compartments that
resembled little rooms with surrounding walls.
Hooke named these compartments cells. The Hooke
observed were not living. He concentrated his study only on the
structure, particularly the cell wall, and did not pursue his
investigation of the cell content.
5. Anton van Leeuwenhoek
(1632-
1723)
In 1674, the Dutch inventor Anton van Leeuwenhoek
observed red blood cells, sperm cells, and a multitude of single-
celled organisms in pond water. He discovered free cells and
observed the nucleus within some red blood cells. It was he who
also discovered bacteria, free-living and parasitic protists, and
many other microscopic organisms. His researches opened up an
entire world of microscopic life to other scientists.
6. ROBERT brown(1773-
1858)
Another scientist, a Scottish botanist named Robert Brown,
discovered the nucleus in 1831. He also theorized that this structure is
a fundamental and constant component of the cell.
Aside from giving the cell nucleus its name. Brown also
honoured for his discovery of cell phenomenon called Brownian
Movement, the random movement of minute particles of matter
suspended in a fluid. He came about this discovery in 1827, when he
observed the movement of plant spores floating in water.
7. Felix dujardin(1802-
1860)
In 1835, a French biologist, Felix Dujardin found out that living
cells contain an internal substance. Not knowingly exactly what this
substance was, Dujardin gave it the name sarcode.
sarcode
8. Jan Evangelista Purkenji
(1787-
1869)
It was a Bohemian physiologist, Jan Evangelista Purkenji who
made a thorough investigation of this internal material. He gave it the
name protoplasm, the colloidal substance in the cell.
protoplasm
12. Scleiden and schwann
Jointly, Schleiden and Schwann came out with the
theory that all living things are composed of cells.
13. Rudolph virchow
(1821-
1902)
Twenty years later, in 1858, a German biologist, Rudolph
Virchow theorized that all living cells come from pre-existing living
cells. His conclusion arose from observing dividing cells during his
work.
CELL DIVISION
14. Cell theory
These observations became a major components of the cell
theory. The cell theory states that:
(1) all living things are composed of one or more cells and
cell products
(2) all living cells come from other living cells by the process
of cell division
(3) cells are basic units of structure and function in organisms
18. Assessment
TEST I. IDENTIFICATION
Instruction: Identify the person who made the significant discovery of the following statement. Refer your
answer from the ‘Name Bank’. WRONG SPELLING IS CONSIDERED WRONG.
Brown Hooke Leeuwenhoek Dujardin
Purkenji Schleiden Schwann Virchow
1. He made a thorough investigation of the internal material and named it ‘protoplasm’.
2. He concluded that all animals are composed of cells.
3. He named the tiny compartments from the cork as cells.
4. He theorized that the nucleus is a fundamental and constant component of the cell.
5. He discovered bacteria, free-living and parasitic protists, and many other microscopic organisms.
6. He found out that living cells contain internal substance and he named it sarcode.
7. He was honoured for his discovery of cell phenomenon called Brownian Movement.
8. He stated that all plants are composed of cells.
9. The scientist who discovered that cells are came from existing cells by division process.
10. They came out with the theory that all living things are composed of cells.
19. Assessment
TEST I. IDENTIFICATION
Instruction: Identify the person who made the significant discovery of the following statement. Refer your
answer from the ‘Name Bank’. WRONG SPELLING IS CONSIDERED WRONG.
Brown Hooke Leeuwenhoek Dujardin
Purkenji Schleiden Schwann Virchow
1. He made a thorough investigation of the internal material and named it ‘protoplasm’.
2. He concluded that all animals are composed of cells.
3. He named the tiny compartments from the cork as cells.
4. He theorized that the nucleus is a fundamental and constant component of the cell.
5. He discovered bacteria, free-living and parasitic protists, and many other microscopic organisms.
6. He found out that living cells contain internal substance and he named it sarcode.
7. He was honoured for his discovery of cell phenomenon called Brownian Movement.
8. He stated that all plants are composed of cells.
9. The scientist who discovered that cells are came from existing cells by division process.
10. They came out with the theory that all living things are composed of cells.
PURKENJI
SCHWANN
HOOKE
BROWN
LEEUWENHOEK
DUJARDIN
BROWN
SCHLEIDEN
VIRCHOW
SCHLEIDEN and SCHWANN
