CH-5:The Fundamental Unit Of
Life
>Cell is the basic fundamental, structural
and functional unit of living organisms.
Discovery of Cell
ROBERT HOOKE IN 1665 EXAMINED A THIN
SLICE OF CORK UNDER A PRIMITIVE
MICROSCOPE.
HE OBSERVED THAT THE CORK CONSIST OF
SMALL BOX-LIKE STRUCTURES RESEMBLING
HONEYCOMB.
HE CALLED THESE SMALL STRUCTURES
CELLS.
BASIC CHARACTERISTICS OF CELLS ARE AS
FOLLOWS;
1. CELLS HAVE THE ABILITY TO REPLICATE
INDEPENDENTLY.
2. THEY CONTAIN HEREDITARY INFORMATION.
, 2
3. CAN PERFORM ALL LIFE SUSTAINING
ACTIVITIES ON THEIR OWN.
DIFFERENCES BETWEEN UNICELLULAR AND
MULTICELLULAR ORGANISMS
UNICELLULAR MULTICELLULAR
ORGANISMS ORGANISMS
A single cell constitutes Two or more cells
the whole organism. constitutes the whole
organism.
There is no division of There is a division of
labour, cell organelles labour and each cell
performs specific performs a particular
functions within the function within the
cell. organism.
For example: Amoeba, For example: Plants ,
Chlamydomonas, Animals ,humans, etc.
bacteria , etc.
STRUCUTURAL ORGANISATION OF A CELL
1. Plasma or Cell Membrane:
>outermost living ,thin and delicate coverning
of cell.
2
Life
>Cell is the basic fundamental, structural
and functional unit of living organisms.
Discovery of Cell
ROBERT HOOKE IN 1665 EXAMINED A THIN
SLICE OF CORK UNDER A PRIMITIVE
MICROSCOPE.
HE OBSERVED THAT THE CORK CONSIST OF
SMALL BOX-LIKE STRUCTURES RESEMBLING
HONEYCOMB.
HE CALLED THESE SMALL STRUCTURES
CELLS.
BASIC CHARACTERISTICS OF CELLS ARE AS
FOLLOWS;
1. CELLS HAVE THE ABILITY TO REPLICATE
INDEPENDENTLY.
2. THEY CONTAIN HEREDITARY INFORMATION.
, 2
3. CAN PERFORM ALL LIFE SUSTAINING
ACTIVITIES ON THEIR OWN.
DIFFERENCES BETWEEN UNICELLULAR AND
MULTICELLULAR ORGANISMS
UNICELLULAR MULTICELLULAR
ORGANISMS ORGANISMS
A single cell constitutes Two or more cells
the whole organism. constitutes the whole
organism.
There is no division of There is a division of
labour, cell organelles labour and each cell
performs specific performs a particular
functions within the function within the
cell. organism.
For example: Amoeba, For example: Plants ,
Chlamydomonas, Animals ,humans, etc.
bacteria , etc.
STRUCUTURAL ORGANISATION OF A CELL
1. Plasma or Cell Membrane:
>outermost living ,thin and delicate coverning
of cell.
2
