Scientists, Cell Theory and Prokaryote vs. Eukaryote

Download Report

Transcript Scientists, Cell Theory and Prokaryote vs. Eukaryote

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