PROPONENTS OF THE CELL THEORY (1st lesson)

Zacharia Janssen

(1590)

-together with Hans Janssen invented the first primitive microscope, can magnify objects 3-9x

Robert Hooke

(1665)
- English Scientists and Microscopist
- described a honeycomb like network of cellular in cork slice
using his primitive compound microscope.
- used the term cells to describe units in plant tissue.
- only saw cell walls because cork cells are dead.
- coined the word cell.
- published his findings in his famous work Micrographia

Anton Van Leeuwenhoek

(1673)
- first man to witness a live under a microscope (1674), using a drop of pond water
- named the moving organisms “animalcules” (“little animals”).
- He was also the first person, using a microscope, to observe clearly and to describe red blood cells in humans and other animals, as well as sperm cells.
- Made over 400 microscopes. A simple microscope can magnify objects about 275x.

Rene’ Joachim Henri  Dutrochet

(1824)
- formulated one of the fundamental tenets of modern cell theory by declaring that "the cell is the fundamental element of organization"

Robert Brown

(1830)
- discovered the nucleus in plant cell.

Johannes Evangelista Purkinje

(1831)
- first to use the word ‘protoplasm’ in the modern sense

Felix Dujardin

(1835)
- many living organisms are composed of a single cell
- first to state that cells were not hollow and described about the jellylike material in animal cells and termed it as sarcode (Gr. sari. flesh).
- Sarcode is currently known as protoplasm and was later found that it is present in living plant cells too.

Matthias Jacob Schleiden

(1838)
- concluded that all plant tissues are composed of cells and that an embryonic plant arose from a single cell. 
- declared that the cell is the basic building block of all plant matter.

Theodore Schwann

(1839)
- stated that all animals are  composed of cells
- ending speculations that plants and animals were fundamentally different in structure.  Schwann described cellular structures in animal cartilage (rigid extracellular matrix)

Rudolf Ludwig Karl Virchow

(1855)
- “All cells come from previously existing cells.”

Exceptions to the theory

- Viruses are not made up of cells
- The first cell did not originate form a pre-existing cell.

Cell

The _____ is the fundamental unit of structure and function in living things.

Cell

All _____ come from pre-existing cells by division.

Energy flow

_____ (metabolism and biochemistry) occurs within cells.

hereditary information (DNA)

Cells contain _____ which is passed from cell to cell during cell division.

cells

All known living things are made up of _______

organism

The activity of an _____ depends on the total activity of independent cells.