Aim: How are cells classified?

How do these cells compare? SIMPLE COMPLEX

Cells are broken down into two main classes:

Prokaryotes: Were probably the first life forms to appear on earth 3.5 billion years ago What were the conditions on Earth at this time? Hot Little Oxygen Abundant Lightning 4) Volcanic Activity Harsh Early Earth

Why do you think Prokaryotes were the first life forms on earth? Simple Structures Their ability to tolerate harsh environments Their ability to adapt to changing environments

What are some features of prokaryotes? Prokaryotes do not have nuclei, they do have DNA. Prokaryotes have NO NUCLEUS!! Have few organelles (mini-organs) PROKARYOTES = BACTERIA

What organisms are made up of eukaryotic cells? Plants Protists Animals Fungi All other living things are made up of Eukaryotic Cells

What are some features of typical eukaryotic cells? They are more complex Appeared later on earth They have nuclei They are larger Have more organelles Have membrane bound organelles

Eukaryotes

CELL TYPES EUKARYOTIC HAVE ORGANELLES HAVE NUCLEUS MODERN CELLS All other living things: animals, plants, fungi, protist (unicellular organisms) PROKARYOTIC HAVE only a few ORGANELLES HAVE NO NUCLEUS PRIMITIVE CELLS Only Bacteria

Membrane –bound organelles Review Chart: Prokaryotes Eukaryotes Nucleus Genetic Information Cytoplasm Cell Membrane Cell Wall Ribosomes Size Membrane –bound organelles  In cytoplasm In nucleus      Some do   smaller Larger 

What do all cells have in common? Cell membrane – gives shape to the cells and allows things in and out. The cytoplasm – the jelly like material where all cell parts are found

ENDOSYMBIOTIC THEORY