Fundamental Unit of Life – Cell
All living organisms are made of tiny structural and functional units called cells. The cell was first
observed by Robert Hooke in 1665. Cell theory was proposed by Schleiden and Schwann and later
modified by Virchow.
Scientist Contribution
Robert Hooke Observed cork cells
Leeuwenhoek Observed living cells
Schleiden & Schwann Proposed cell theory
Virchow All cells arise from pre-existing cells
Key points:
• Cell is the basic unit of life.
• Organisms may be unicellular or multicellular.
• Cells perform all life processes.
, Structure of a Cell
Major parts of a cell are: cell membrane, cytoplasm and nucleus. Plant cells also have a cell wall
and chloroplasts.
The cell membrane controls movement of substances. Cytoplasm contains cell organelles.
Nucleus controls all activities of the cell.
All living organisms are made of tiny structural and functional units called cells. The cell was first
observed by Robert Hooke in 1665. Cell theory was proposed by Schleiden and Schwann and later
modified by Virchow.
Scientist Contribution
Robert Hooke Observed cork cells
Leeuwenhoek Observed living cells
Schleiden & Schwann Proposed cell theory
Virchow All cells arise from pre-existing cells
Key points:
• Cell is the basic unit of life.
• Organisms may be unicellular or multicellular.
• Cells perform all life processes.
, Structure of a Cell
Major parts of a cell are: cell membrane, cytoplasm and nucleus. Plant cells also have a cell wall
and chloroplasts.
The cell membrane controls movement of substances. Cytoplasm contains cell organelles.
Nucleus controls all activities of the cell.
