1.
CELL STRUCTURE
CELL THEORY
PRESENTATION
BY GROUP ONE

2.
THE CELL THEORY
BRIEF HISTORY
• Cell is the basic unit and functional unit of life OR The cells is
the building blocks for all living organisms.
• The cell was first discovered by Robert Hooke in1665 with
the aid of a microscope.
• He discovered a cell from a cork under the microscope.
• Since there were no advanced microscopes at that time, his
experiment was not approved.
• This was because the cells in the cork were dead and
therefore he observed that they were empty.

3.
• Later in 1839,two German scientists; Mathias Schleiden and
Theodor Schwann discovered that cells are present in all
living organisms.
• Mathias Schleiden brought about cells existing in plants.
• Theodor Schwann also discovered that cells are present in
animals.
• In 1855, Rudolf Virchow, another German scientist
discovered that cells exist from pre-existing cells.
• These discoveries brought about the theory.

4.
THE CELL THEORY
• All living things are made up of cells
This means that in order for something to be alive, it must either be a
cell or contain cells.
All animals and plants are made up of cells.
• The cell is the basic unit of life
This means that they are the fundamental units of a living organism’s
structure.
The cells help all organisms to carry out their life processes.

5.
• All cells come from pre-existing cells
This means that cells do not just appear out of the thin air.
New cells are always made from current cells.
Cells have been replacing themselves continuously ever since.
As time went by, there has been some other discoveries which has led
to the modernization of the theory.

6.
THE MODERN THEORY
The modern version of the cell theory includes the idea that;
• Energy flow occurs within cells
This means that metabolism and biochemistry happens within cells
• Heredity information is passed on from cell to cell
Cells contain genetic information in the form of DNA passed on from
one cell to cell during division.
• All cells have the same basic chemical composition
In organisms of similar species, all cells are fundamentally the same.

7.
END OF PRESENTATION