Cell theory

Question 1

What is the compound microscope?

Answer 1

The compound microscope was invented in the late 1500s. The Dutch eyeglass maker Zacharias Janssen invented it. A compound microscope contains two or more lenses.

Question 2

What happened in 1665?

Answer 2

In 1665, the English scientist Robert Hooke used the three-lens compound microscope to examine thin slices of cork of a species of oak tree. He observed that cork is made of tiny, hollow compartments that reminded Hooke of small rooms found in a monastery, so he gave them the same name: cells.

Question 3

What happened in 1674?

Answer 3

The Dutch tradesman Anton van Leeuwenhoek was studying new methods for making lenses to examine cloth. His single-lens microscopes were much more powerful than the crude compound microscope that Hooke had used. In 1674, Leeuwenhoek became one of the first people to describe living cells.

Question 4

What happened in 1838?

Answer 4

The German scientist Matthias Schleiden used compound microscopes to study plant tissue. In 1838 he came to the result that plants are made up of cells.

Question 5

What happened in 1839?

Answer 5

The German scientist Theodor Schwan studied animal cells and was struck by the structural similarities between plant and animal cells. Schwan concluded that all animals are made up of cells. In 1839 he published the first statement of cell theory, concluding that all living things are made up of cells.

Question 6

What happened in 1855?

Answer 6

In 1855, the German scientist Rudolf Virchow reported that all cells come from preexisting cells.

Question 7

REMEMBER!

Answer 7

The major principles of the cell theory are the following:

1. All organisms are made up of cells.
2. All existing cells are produced by other living cells.
3. The cell is the most basic unit of life

Early studies led to the development of the cell theory!