CELL THEORY makes 3 Claims

• 1. All living organisms are made of 1 or more cells

• 2. Cells come only from other living cells

• 3. The cell is the basic unit of life ( smallest structure which can carry out life processes )

Scientific claims must be based on evidence.

• What is the EVIDENCE used to propose the idea that

All living things are made of one or more cells?

Evidence for claim #1 of cell theory begins with Robert Hookes observation of Cork ( from a tree ) in 1665. his actual drawing is on

the lower left. Hooke used the word Cells for the small boxes he saw.

Mathias Schlieden observes cells in all plants he studies. He proposes the claim

that all plants are made of cells

Theodore Schwann observes animal tissues. Proposes the claim that all animals are made of cells

Animal cells

FUNGUS CELLS

Rudolph Virchow proposes the claim that living cells come only from other living cells when cells divide.

CELLS DIVIDING to form new ( daughter ) Cells

First Cell divisions of a Frog egg… forming a small frog Embryo

Human Cell beginning to divide. You can see chunks of DNA called chromosomes being pulled to opposite sides of the cell as

it divides

CELL THEORY• 1. All living organisms are made of 1 or more

cells

• 2. Cells come only from other living cells

• 3. The cell is the basic unit of life ( smallest structure which can carry out life processes