cell theory

Light microscope

Visible light is passed through a specimen and then through glass lenses

Scanning electron microscope

Electron beam study’s the surface details of a cell

Transmission electron microscope

Electron beam study’s the internal structure of thinly sectioned specimens

Robert hook

First indetified cells in 1665

Used early compound microscope

Looked at a thin slice of cork(plant material)

Anton van Leeuwenhoek

Used a simple microscope

Took a sample of pond water- discovered a world of tiny living organisms

1838 Matthias Schleiden

All plants are made of cells

1839 Theodor Schwann

All animals are made of cells

1855 Rudolf Virchow

Cells come from preexisting cells

Cell theory states

All living things are composed of cells

Cells are the basic units of structure and function in living things

New cells are produced from existing cells

Similarities between prokaryotes and eukaryotes

Surrounded by a barrier called a cell membrane

At some point they will contain dna

Prokaryotes

No nucleus present

No membrane bound organelles

Smaller in size

Simple form

Example: bacteria

Eukaryotes

Nucleus present

Have membrane bound organelles Smaller

Larger in size

More complex

Example: plants, animals, fungi

How are prokaryotes harmful

Causes diseases

How are prokaryotes helpful

Help nitrogen cycle

Used to make certain food

Aid in digestion

Decompose organic matter to form soil