KEY CONCEPT Cells are the Basic unit of life.

The cell theory grew out of the work of many scientists and improvements in the microscope. Many scientists contributed to the cell theory.

Early Contributions Hooke - First person to see cells, he was looking at cork and noted that he saw "a great many boxes. Named cells. (1665) Leeuwenhoek - Observed living cells in more detail in pond water, which he called "animalcules" (1674)

Early Contributions Schleiden - Observed tissues of plants contained cells. He was the first to note that plants are made up of cells. ( 1838) Schwann – Concluded that all living things are made up of cells. He observed tissues of animals had cells (1839) Virchow - Also reported that every living thing is made of up vital units, known as cells. He predicted that cells come from other cells. (1850 )

Important technological advances: Improvements to the lenses of microscopes have allowed scientists to study cells in more detail.

The cell theory grew out of the work of many scientists and improvements in the microscope. Many scientists contributed to the cell theory. More was learned about cells as microscopes improved.

The cell theory grew out of the work of many scientists and improvements in the microscope. Many scientists contributed to the cell theory. More was learned about cells as microscopes improved. The cell theory is a unifying concept of biology.

Early studies led to the development of the cell theory. The Cell theory has three principles. All organisms are made of cells.

Early studies led to the development of the cell theory. The Cell theory has three principles. All organisms are made of cells. All existing cells are produced by other living cells.

Early studies led to the development of the cell theory. The Cell theory has three principles. All organisms are made of cells. All existing cells are produced by other living cells. The cell is the most basic unit of life.

Early studies led to the development of the cell theory. The cell theory is one of the first unifying concepts in biology.

There are two cell types: eukaryotic cells and prokaryotic cells.

There are two cell types: eukaryotic cells and prokaryotic cells. Eukaryotic cells have a nucleus. nucleus cell membrane

There are two cell types: eukaryotic cells and prokaryotic cells. Eukaryotic cells have a nucleus. Prokaryotic cells do not have membrane- bound organelles. nucleus organelles cell membrane

There are two cell types: eukaryotic cells and prokaryotic cells. Prokaryotic cells do not have a nucleus. nucleus organelles cell membrane

There are two cell types: eukaryotic cells and prokaryotic cells. Prokaryotic cells do not have a nucleus. Prokaryotic cells do not have membrane-bound organelles. nucleus organelles cell membrane cytoplasm

Bacteria Images Bacteria that causes Anthrax

Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells. All cells share certain characteristics.

All cells share certain characteristics. Cells tend to be microscopic. Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells. All cells share certain characteristics. Cells tend to be microscopic. Bacterium (colored SEM; magnification 8800x)

All cells share certain characteristics. Cells tend to be microscopic. Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells. All cells share certain characteristics. Cells tend to be microscopic. All cells are enclosed by a membrane. cell membrane Bacterium (colored SEM; magnification 8800x)

All cells share certain characteristics. Cells tend to be microscopic. Prokaryotic cells lack a nucleus and most internal structures of eukaryotic cells. All cells share certain characteristics. Cells tend to be microscopic. Cell Membrane- outer boundary, some things can cross the cell membrane. Cytoplasm- Fluid material within the cell DNA- genetic material Ribosomes- make protein for use by the organism cell membrane Bacterium (colored SEM; magnification 8800x) cytoplasm

Comprehension Check Answer true or false: Robert Hooke was the first person to see cells. Bacteria cells have a cell membrane. The Cell Theory was developed by a single scientist. Plant cells have cytoplasm. Cells taken from fungi do not have DNA. Cells can only come from pre-existing cells. It only took five years to develop the Cell Theory.