Kingdom Archaebacteria

Question 1

General Description

Answer 1

• Some of the oldest organisms on earth (in terms of evolution)
• Live in extreme environments (very hot, acidic and salty conditions)

Question 2

Structure

Answer 2

• Unicellular, prokaryotic
• Look similar to bacteria

Question 3

Classification

Answer 3

Based on metabolism of four possible types

Question 4

Classification - Methanogens

Answer 4

• Anaerobic (live without oxygen)
• Produce almost all the methane gas in the world
• Methane comes from methanogens in the guts of herbivores (like cows)
• Can be found in: salt water, Marnie, fresh-water, bogs, deep soils and sewage treatment facilites

Question 5

Classification - Halophiles

Answer 5

• Exist in salty conditions (ie. Dead Sea, Great Salt Lake or where salt concentration is very high)
• Require salt for growth
• Cell walls, ribosomes and enzymes are stabilized by Na+

Question 6

Classification - thermoacidophiles/extreme thermophiles

Answer 6

• Exist in hot acidic environments
• Require very hot temperature for growth (80-105 degrees)
• Some require low Ph’s for survival
• Membranes and enzymes are unusually stable at high temps
• Found in hot, sulfur-rich environments like hot springs, geysers and fumaroles in Yellowstone National Park, thermal vents and cracks in the ocean floor

Question 7

Classification - Psychrophiles

Answer 7

• Discovered most recently
• Live in glacial ice or permafrost in or near the Arctic or Antarctic
• Tend to make natural anti-freeze
• Their existence suggests the possibly that life could exist on other planets which have cold environments