The Cell TheoryThe Cell Theory

Important people, and dates to Important people, and dates to remember about the development remember about the development

of the theory. of the theory.

Anton van LeeuwenhoekAnton van Leeuwenhoek

• 1632-1723

• Made powerful microscopes out of magnifying glasses.

• The first man to witness a live cell under a microscope.

Robert HookeRobert Hooke

• 1635-1703• When looking at cork

under the microscope, he described it as like the tiny rooms that monks lived in called Cellula.

• He was the first to call these tiny compartments “cells”.

Robert BrownRobert Brown

• 1831

• Botanist.

• Concluded from his studies that all plants had cells with a nucleus.

Three scientists are accredited for Three scientists are accredited for developing the theorydeveloping the theory

• 1838,Matthias Schleiden- Concludes that all plants are made up of cells.

• 1839, Theodor Schwann- Concludes that all animals are made up of cells.

• 1855, Rudolf Virchow- Concludes that all cells come from pre-existing cells.

The cell theoryThe cell theory

• All living things are made up of cells.

• The cell is the basic structure and function in all living things. (all activities needed to sustain life occur within cells)

• All cells come from pre-existing cells.

ExceptionsExceptions

• As with all theories there are a few exceptions:– Mitochondria and chloroplasts have their own

DNA and can replicate on their own!– Viruses are not considered to be living, they

cannot replicate on their own even though they may contain genetic information.

– The first cell could not have come from a pre-existing cell.

Why viruses are not considered to Why viruses are not considered to be living.be living.

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