Scientists, Cell Theory and Prokaryote vs.

Eukaryote

What is a Cell? Cell – Basic unit of living things.

Organisms are either: Unicellular – made of one cell such

as bacteria and amoebas.OR

Multicellular – made of many cells such as plants and animals.

ALL LIVING THINGS :

Are made of cells Can reproduce Have genetic code Grow and develop Obtain/use materials and energy Respond to environment Maintain homeostasis Change over time

Cell Theory Confirmed discoveries that all scientists

believe to be true about cells:

1. Cells are the basic unit of life.

2. All living things are made of cells.

3. New cells are produced from existing cells.

Microscopes Light Microscope – magnifies tiny

organisms up to 1,000 times. Uses light and lenses (we use these).

Electron Microscope – magnifies up to a million times. Uses electrons. TEM – Transmission Electron Microscope –

transmits electrons through a slice of an object. Shows internal structure.

SEM – Scanning Electron Microscope – scans the outside of an object (shows 3-D view of the surface).

The Discovery of Cells

before nucleus

true nucleus

Prokaryotes NO nucleus NO organelles

ALL are unicellular Smaller than eukaryotic cells

Forerunner to eukaryotic cells (smaller and more simple)

DNA – single strand and circular Ex: ALL Bacteria

Eukaryotes Has a nucleus with a nuclear envelope Bigger and more complex than

prokaryotes

Have Organelles DNA – double-stranded and forms

chromosomes (highly organized)

Can be uni- OR multicellular Ex: animals, plants, fungi

Similarities Contain all four biomolecules

Have ribosomes

Have DNA

Similar Metabolism

Can be unicellular

Have cell membranes