Unit 4-Cells and Systems

The Cell Theory

In biology, the cell theory is a scientific theory which describes the properties of all cells.

◦There are 5 scientists that made large contributions to the cell theory.

◦ Robert Hooke

1665 -English scientist that cut a thin slice of cork and looked at it under his microscope. To him, the cork seemed to be made up of empty little boxes, which he named cells.

◦Anton Van Leewenhoek

1673 Dutch naturalist who created a very powerful (for the time period) single lens microscope, He observed pond water. In pond scum he discovered small animals (protists), and also discovered bacteria while examining scraping of crud from his teeth.

◦Matthias Schleiden

1838 German botanist who determined plants are composed of cells.

◦Theodor Schwann

German physiologist and histologist who in 1838 and 1839 identified the cell as the basic structure of plant and animal tissue (1810-1882)

◦Rudolph Virchow

1858 - A doctor who stated that all living cells come from other living cells (part 3 of the cell theory)

The Cell Theory

◦The cell theory is made up of three statements. You must memorize these.

◦

1.All Living things are made of cells

2.Cells are the basic building block of life

3.All cells come from pre-existing cells

Plants vs. Animal Cells

◦Plant and Animal cells have similarities and differences.