Biology IB 2.1

Contributions to Cell Theory

Jansen: Invented the Compound Microscope

Hooke: Examined cork under the Compound Microscope

Van Leeuwenhoek: Observed unicellular organisms and the theories

Shleiden: Says that all plants are made up of cells

Schwann: Says that all plants are made up of living cells

• ALL LIVING THINGS ARE MADE OF CELLS
• CELLS ARE THE SMALLEST UNIT OF LIFE
• EXISTING CELLS HAVE COME FROM OTHER CELLS

Evidence of Cell Theory

a. All living things are made up of cells.

When they appear under a microscope, they are constantly composed of cells.

Exceptions:-

Muscle cells

-More than one nucleus

-Longer than usual (300mm)

-Surrounded by one plasma membrane, yet has several membrane-bound nuclei

Fungal cells

-Very large, many nuclei, continuous cytoplasm

-Cell walls are composed of chitin

Proctotista

-They can carry out all the functions of life

-They are unicellular

b. Cells are the smallest unit of life.

They are the smallest unit of organization that can show all characteristics of living process'. Organelles often require the cooperation of other organelles for successful functioning.

c. Cells…