Let’s Learn About the Two Types of Cells What is the difference between a prokaryote and a eukaryote?

What are Prokaryotes? Prokaryotes are the simplest life forms exhibiting cellular structure, and were Earth’s first cells. Two major forms (kingdoms): Eubacteria and Archaebacteria Example: Bacteria Color-enhanced scanning electron micrograph showing Salmonella (red) invading cultured human cells Image

Prokaryotes live in many environments Prokaryotes are the Earth’s most abundant inhabitants. They can survive in a wide range of environments and obtain energy in a variety of ways. Ex. Deep ocean volcano hot springs Left to right; deep sea prokaryote; prokaryote from volcano; prokaryotes from Yellowstone National Park hot springs Image Image Image

Prokaryotes are simple They have no nucleus, and no membrane-bound organelles They may have flagella or cilia for movement As a single-celled organism, it has to conduct all life processes itself.

How did eukaryotes come about? Eukaryotes arose from prokaryotes They developed into larger, more complex organisms Includes plants, animals, fungi & protists Image

Prokaryotes and Eukaryotes ALL cells have two characteristics in common: 1. surrounded by a barrier (cell membrane) 2. At some point in their lives, they contain DNA 3. contain cytoplasm and ribosomes Two major differences: Prokaryotes NO nucleus; no membrane-bound organelles Eukaryotes Have a nucleus and membrane-bound organelles

Contain membrane-bound organelles Prokaryotes Eukaryotes Larger & complex; Includes plants, animals, fungi & protists Simplest life forms Earth’s first cells Most abundant inhabitants Cytoplasm ribosomes Cell membrane DNA No nucleus; no membrane-bound organelles Great variety: single-celled to multi-cellular organisms May have flagella or cilia for movement Archaea = “Ar kay ah” 2 Major forms: Eubacteria & Archaebacteria Contain membrane-bound organelles Ex. bacteria

Eukaryotic Cells Image Image