CELL THEORY

MAJOR PRINCIPLES OF THE CELL THEORY

• All organisms are made of one or more cells.
• All existing cells are produced by other living cells.
• The cell is the most basic unit of life.

MAJOR CONTRIBUTORS TO THE CELL THEORY

• Hooke: the first to identify and name the cell.
• Leeuwenhoek: made better lenses and observed cells in greater detail
• Schleiden: first to note that all plants were made of cells.
• Schwann: concluded that all living things were made of cells.
• Virchow: proposed that cells come from other cells.

PROKARYOTIC CELLS

• Do not have a nucleus or other membrane-bound organelles.
• Cells DNA are suspended in the cytoplasm.
• All prokaryotic cells are microscopic.

EUKARYOTIC CELLS

• Have a nucleus and other membrane-bound orgenelless.
• The nucleus encloses the genetic information.
• Eukaryotic cells may be multicellular or single-celled organisms.