1. Archaea – The beginning
Do Now:
Read the article “Introduction to the Archaea”
Why are they life’s extremists?

2. The 3 domain system

3. How Classification Works
Each domain is further divided into kingdoms, which are then divided into phyla, etc. etc.
The hierarchy of classification is on your notes
It can be remembered with a simple mnemonic device:
Kinky People Cry Out For Good Sex
Kingdom Phylum Class Order Family Genus Species

4. Big Differences
Strangely, eukaryotes have more in common with archaea than with bacteria!
Archaea are the organisms alive today that most resemble the first cells that arose on Earth
rRNA sequences – since every organism has them – are used to determine evolutionary relationships (more similar sequence = more recent ancestor)

5. Archaea are the producers of hydrothermal vent communities
Where life began?
Similar to archaea.
Chemoautotrophs

6. Deep-Sea Hydrothermal Vent

9. Archaea from the Deep! CHEMOAUTOTROPHS

15. How Domains are Defined
Bacteria and Archaea are prokaryotes; Eukayra is the only domain of Eukaryotes
The 3 domains have chemical differences in cell membrane lipids
There are numerous other differences between the three, including what antibiotics kill them.

16. Domain Archaea
Most are extremophiles: organisms which survive in extreme environments, including
Thermophiles: high temperatures
Thermoacidophiles: high temps & low pH
Halophiles: high salt
Hyperthermophiles: extreme high heat (121oC)

17. Use the Roots!!!
Fill out the word root meanings on your notes! Use them to decode the meanings of the different types of archaea.
Where would a halothermophile live?
A hyperacidophile?

18. What you need to Know
Name the three domains of life, and identify the two domains of prokaryotes.
Identify the domain which is most similar to the common ancestor of all life (archaea)
Explain how organisms are classified today (rRNA similarity)
Use word roots to determine where groups of archaea live or what they do