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Cell• A cell is the basic unit of structure

and function in living things. • A cell is like the bricks of a

building

Microscope• The invention of a microscope

made it possible to see cells.• A microscope is an instrument that

makes small objects larger

Microscope• Two types

– Simple- Has one lens• Examples

– Compound- Has more than one lens• Examples

Convex Lens• Is a lens that is thicker in the

middle and thin on the edges.• A convex lens is in a microscope. • Light hits the sides of the lens and

the lens bends the light inwards. When the light hits the eye, the object appears bigger.

Resolution• The ability to clearly distinguish

individual parts of an object.

Magnification• Magnification is the ability to make

things look larger.• Lens or lenses in a microscope

bend the light to magnify the object

Cell Theory• The cell theory was developed by

taking many scientists’ findings and putting their ideas together.

• The cell theory states:– All living things are made up of cells– Cells are the basic unit of structure and

function of an organism– Cells are produced from other cells

Robert Hooke• Was the first person to see a cell.

He did this by looking at cork from a cork oak tree.

• Named the cell a cell because the cells reminded him of small rectangular rooms (jail cells)

Microscope Timeline

1590

Hans Janssen and his son made one of the

first compound microscopes

1660

Robert Hooke improved the microscope by adding an oil lamp

1683

Anton Leeuwenhoek made a simple

microscope that could magnify an object 266 times. He was the first to see many one celled

organisms

1886

The modern light compound microscope

was invented

1981

The STM was invented. It can magnify an

object 1,000,000 times

Electron Microscope• Uses a beam of electrons to form

an image. Is much clearer than a compound microscope