THE PEOPLE WHO FIRST INVESTIGATED CELLS

Zacharias Janssen:Zacharias Janssen:

• 1590• Dutchman; maker of reading

glasses• Put 2 magnifying glasses in a

tube. (1st crude compound microscope)

Anton Van Anton Van Leewenhoek:Leewenhoek:• Mid-1600’s• Dutch scientist• Saw organisms

in pond water by making a simple microscope with a tiny glass bead for a lens

Anton Van Anton Van Leewenhoek:Leewenhoek:

Robert Hooke:Robert Hooke:

• 1665• English scientist• Saw cork slices under the

microscope• Named the “little boxes” he saw

“cells”

Matthias Schleiden:Matthias Schleiden:

• 1838• German Scientist• Studied plant parts with

microscope• Said all plants were made of cells

Theodor Schwann:Theodor Schwann:

• 1839• German Scientist• Deduced that all animals were

made up of cells

What was “Spontaneous What was “Spontaneous Generation”?Generation”?

• People thought that life could be created “spontaneouslyspontaneously”

• They even had “recipesrecipes” for certain living things:

To create mice, a recipe called for dirty underwear and wheat grain to be mixed in a bucket and left open outside. In 21 days or less, you would have mice. The real cause may seem obvious from a modern perspective, but to the proponents of this idea, the mice spontaneously arose from the wheat kernels.

Rudolph Virchow:Rudolph Virchow:

• ~1855• German Doctor• Deduced that all cells come from

other cells

Cell TheoryCell TheoryWhat we now believe to be true

about cellsThere are three parts:1) All organisms are made up of one

or more cells2) Cells are the basic units of

structure & function in all organisms

3) All cells come from cells that already exist

Characteristics of Characteristics of Living ThingsLiving Things

Traits something must have in order to be considered alive.

Characteristics of Life Video Clip

Characteristics of Characteristics of Living ThingsLiving Things

Traits something must have in order to be considered alive. 1) Reproduces

2) Grows & develops3) Sensitivity – responds to outside world4) Uses energy - eats food or makes food5 ) Can move in some way6) Breathes/exchanges gas7) Excretes – gets rid of wastes