2. Characteristics Most numerous and widespread organisms on Earth. Includes the smallest and simplest life-forms Unicellular Single-celled Live in chains of clusters Only Kingdom made of prokaryotic organisms Have no nucleus

3. 2 Basic Classifications of Bacteria Archaebacteria Belong to the Domain Archaea Eubacteria Belong to the Domain Bacteria

4. The Domain Archaea Three Main Types: Heat-lovers Thermophiles Salt-lovers Halophile Methane-lovers Methanogens

5. Thermophiles Live in ocean vents and hot springs. They live in very hot water, usually from 60°C to 80°C, but they can survive in temperatures of more than 250° C.

6. Halophiles Live in environments that have high levels of salt, such as the Dead Sea and Great Salt Lake.

7. Methanogens Give off methane gas and live in swamps and animal intestines.

8. Archaebacteria Bacteria that survive best in extreme environments. Examples: hot springs, deep sea vents, boiling muds Includes methane-forming, salt loving and heat loving bacteria. Morning Glory Pool: Yellowstone National Park  The coloring comes from the massive amount of archaebacteria (which are chemo-synthesizers) and can withstand extreme temperatures. Thermoacidophilic bacteria can only live in water which is very hot (70 - 75° C) and as acidic as concentrated sulphuric acid. They are found in hot springs.

9. Eubacteria Known as the true bacteria Found in numerous environments such as the surface of human skin, the intestines of an animal, on a log, etc. Often identified with the Gram Stain Method Gram Negative- cannot retain stain when tested Gram Positive- stain dark blue or violet

10. 2 Major Groups in Kingdom True Bacteria Bacteria and Cyanobacteria

11. Characteristics of True Bacteria Absorb food molecules from their surroundings Rely on other organisms to provide them with food. Decompose other living things to gain energy Due to this they are often called Decomposers Can be beneficial to humans Example: In the intestines, bacteria help digest food properly.

12. Cyanobacteria Live in fresh water Contain chlorophyll and produce their own food Different shapes and attach to each other in long chains or clusters. Example Cyanobacteria: smelly, green scum found on the top of the pond.

13. Three Basic Shapes of Bacteria Cocci Round Responsible for strep throat Bacilli Rod-Shaped Responsible for tooth decay and anthrax Spirilli Spiral-shaped Easiest to identify

14. Archaea vs. Eubacteria Archaea Eubacteria Do not always have cell walls Cell walls (when present) have different chemical compositions Live in harsh environments Always have cell walls Can not survive harsh environments.

15. Movement of Bacteria Bacteria moves in numerous ways Squirming, gliding, and propulsion Movement caused by flagella Flagella move (rotate) to propel the bacteria Like a motor boat

16. Bacteria Reproduction Reproduces through a process called binary fission. Occurs when one single-celled organism splits into two single-celled organisms. Occurs in 4 Steps. Reproduction occurs very quickly.

17. Step 1: Growth The cell grows

18. Step 2: DNA Replication The DNA is copied and attached to the cell membrane.

19. Step 3: DNA Separates The DNA and its copy separate as the cell grows larger.

20. Step 4: Splitting The cell splits into two cells. Each cell has a copy of the DNA.

21. Endospores Most speices of bacteria do well in warm, moist places. In dry or cold surroundings, some species of bacteria will die. In these conditions, other bacteria become inactive and form endospores. An endospore contains genetic information and proteins. It is covered by a thick, protective coat. Many endospores can survive in hot, cold, and very dark places. When conditions improve, the endospores break open and the bacteria become active again.