Discovery Cells (PGS.50-57)

The invention of the microscope made possible for people to discover and learn about cells. A Microscope is an instrument that makes small objects look longer by using lenses.

Teach and design a history.

1590. - First compound microscope. Zacharias Janssen it was a tube with lenses at each end.

1660. – Hooke’s compound microscopes include an oil lamp for lighting.

1674. – Leeuwenhoek’s simple microscope used only one tiny lenses; it could magnified a specimen up to 266 times.

1886. – Modern compound microscope. Ernest Abbé and Carl Zeiss compound light microscope with complex lenses a mirror focuses light up through the specimen magnify a specimen to 1000 times.

1933. – (TEM) Transmit ion Elector microscope Ernest Ruska. Terms and electrons through a many thin slices specimen and can magnify a specimen up to 500000 times.

1965. – (SEM) Scanning Electron Microscope. And seem sends electrons over the surface of a specimen rather than through it. The result is the three dimensional image of the specimen surface SEM´s can magnify a specimen up to 150000 times.

1981. – Scanning Tunneling Microscope (STM) an STM measures electrons that leak, or “tunnel” from the surface of a specimen. STM can magnify a specimen up to 1000000 times.

What the Cell Theory Says Schleiden, Schwann, Virchow, and others helped develop the cell theory. The cell theory is a widely accepted explanation of the relationship between cells and living things.

The cell theory states the following:

· All living things are composed of cells.

· Cells are the basic units of structure and function in living things.

· All cells are produced from other cells.

The cell theory holds true for all living things, no matter how big or how small. Since cells are common to all living things, they can provide information about the functions that living things perform. Because all cells come from other cells, scientists can study cells to learn about growth and reproduction.

BY Jose Vila Reyes

M11