CHAPTER 5: CELL STRUCTURE & FUNCTION

UNIT 4 CELLS: THE BASIC THEORY OF LIFE SECTION 5-1: THE CELL THEORY

• Discuss in detail the discovery of the “cell” by Robert Hooke.

• Discuss the contributions of other scientists leading to the development of the cell theory. • State the cell theory.

• Vocabulary: cell, cell theory

1/26/17 Biology: Cell Structure & Function 2 CELL THEORY

• development & refinement of magnifying lenses & light microscopes made observation & description of microscopic organisms & living cells possible

• many scientists contributed

1/26/17 Biology: Cell Structure & Function 3 TIMELINE OF THE CELL THEORY • lenses used 100s of years ago as magnifiers

• 1632: Anton van Leeuwenhoek • credit for developing 1st microscope • observed pond water & made detailed drawings of each kind of tiny organism living in it (1st to see bacteria & protists)

• 1665: Robert Hooke • used microscope to look at thin slices of plant stems, wood, & pieces of cork  coined term “cell”

• 1833: Robert Brown • noted dark structure near center of cell (nucleus)

• 1838: Matthias Jakob Schleiden – all plants made of cells

• 1839: Theodor Schwann – all animals made of cells too

• 1855: Rudolf Virchow – cells arise from division of preexisting cells 1/26/17 Biology: Cell Structure & Function 4 CELL THEORY

• The cell theory states • All living things are composed of cells. • Cells are the basic units of structure & function in living things. (The cell is the basic unit of life) • All cells come from pre-existing cells.

1/26/17 Biology: Cell Structure & Function 5 VISUALIZING CELL SIZE

1/26/17 Biology: Cell Structure & Function 6 CELL THEORY REVIEW QUESTIONS

• What contributions did van Leeuwenhoek, Hooke, Schleiden, Schwann, & Virchow make in the development of the cell theory?

• What role did the invention of the microscope play in the development of the cell theory?

1/26/17 Biology: Cell Structure & Function 7