THE PEOPLE WHO FIRST INVESTIGATED CELLS Zacharias Janssen

THE PEOPLE WHO FIRST INVESTIGATED CELLS

Zacharias Janssen: • 1590 • Dutchman; maker of reading glasses • Put 2 magnifying glasses in a tube. (1 st crude compound microscope)

Anton Van 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 Leewenhoek:

Robert Hooke: • • 1665 English scientist Saw cork slices under the microscope Named the “little boxes” he saw “cells”

Matthias Schleiden: • • 1838 German Scientist Studied plant parts with microscope Said all plants were made of cells

Theodor Schwann: • 1839 • German Scientist • Deduced that all animals were made up of cells

What was “Spontaneous Generation”? • People thought that life could be created “spontaneously” spontaneously • They even had “recipes” recipes 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: • ~1855 • German Doctor • Deduced that all cells come from other cells

Cell Theory What we now believe to be true about cells There are three parts: 1) All organisms are made up of one or more cells 2) Cells are the basic units of structure & function in all organisms 3) All cells come from cells that already exist

Characteristics of Living Things Traits something must have in order to be considered alive. Characteristics of Life Video Clip

Characteristics of Living Things Traits something must have in order to be considered alive. 1) Reproduces 2) Grows & develops 3) Sensitivity – responds to outside world 4) Uses energy - eats food or makes food 5 ) Can move in some way 6) Breathes/exchanges gas 7) Excretes – gets rid of wastes