- In 1665, Robert Hooke discovered cells in cork and coined the term "cell" from the Latin word "cellula" meaning small compartment. He published his findings in Micrographia. - In 1674, Anton van Leeuwenhoek observed red blood cells, sperm, bacteria and single-celled organisms using his improved microscope. - In 1839, Theodor Schwann and Matthias Schleiden established the cell theory - that all living things are composed of cells, all cells come from preexisting cells, and the cell is the basic unit of structure and function in living things.

3. 1665- Robert Hooke (English)
discovered cells in a
piece of cork
drew the cells he saw
and also coined the
word CELL.

4. 1665- Robert Hooke (English)
cell is derived from the
Latin word 'cellula‘ -
means small
compartment.
published his findings in
his famous work,
Micrographia

5. 1674- Anton Van Leeuwenhoek
(Dutch)
made single lens
microscope that magnify
objects 200x
observed red blood cells,
spermatozoa, bacteria
and single celled
organisms in pond water

6. 1824- René Henri Dutrochet
(French)
discovered that the
cell is the fundamental
element in the
structure of living
bodies, forming both
animals and plants
through juxtaposition.

7. 1824- René Henri Dutrochet
(French)
Juxtaposition is the
state of being placed
or situated side by
side.
suggested that the
various parts of
organisms are

8. 1831- Robert Brown (Scottish)
discovered that cells
contain a nucleus.
Nucleus is a
membrane- bound
organelle found in
eukaryotic cells. It is
the control center of
the cell.

9. 1835- Felix Dujardin (French)
reported that cells are
not hollow structure
but they are filled with
a thick jelly like fluid
internal substance-
sarcode

10. 1838- Matthias Schleiden
(German)
concluded that all
plants are composed
of cells and that cells
are alive and
contribute to the
functioning of the
organism of which
they are part

11. 1839- Theodore Schwann
(German)
stated that all
animals are
composed of cells.

12. 1839- Jan Evangelista Purkinje
(Bohemian)
investigated the
fluid material in
the cell naming it
Protoplasm

13. 1858- Rudolph Virchow
(German)
stated that all cells
came from other
living cells
“Life is an unbroken
chain of cells going
all the way back to
the first living
thing.”

14. Cell Theory
1.All living things are composed
of cells.
2.All living cells come from
other living cells.
3.Cells are the basic unit of life.

15. a. nutrition
b. digestion
c. absorption
d. biosynthesis
e. excretion
f. egestion

16. g. movement
h. irritability
i. secretion
j. respiration
k. reproduction

17. Cell Functions
• Nutrition- cells obtain food molecules to
support their other activities.
• Digestion- food particles are broken down
into smaller units
• Absorption- cells absorb from their
environment, water, minerals, and other
materials essential for life.
• Biosynthesis- all cells organize complex
molecules from simple building units or
substances.
• Egestion- insoluble, nondigested particles are
eliminated by the cell

18. • Excretion- by-products of all cells which are
not needed for cell functioning are eliminated.
• Secretion- substances that are synthesized
by the cells are expelled from the membrane.
• Movement- includes the locomotion of cells.
• Irritability- cells respond to external factors
around them.
• Respiration- breaking down food molecules
into chemical energy needed by all cells in
order to function.
• Reproduction- a cell copies its DNA and
increases its number by cell division.

24. Cell Part Prokaryotic Cell Plant Cell Animal Cell
Cell membrane present present present
Cell wall present present absent
Nucleus absent present present
Chromosome
Small, circular;
single continous
loop
multiple, large
lines
multiple, large
lines
Ribosomes smaller larger larger
Organelles absent present present
Chlorophyll
If present not
contained in
chloroplast
present absent
Cytoskeleton absent present present
Vacuoles absent large Small
Lysosomes absent rare common