Bacteria and Viruses

1. Bacteria and Viruses Chapter 10

2. Characteristics of Bacteria and Archaea • Bacteria are too small to be seen without a microscope. • They generally come in 3 shapes • Bacilli are rod shaped bacteria and have a large surface area • Cocci are spherical bacteria and do not dry out quickly • Spirilla are long and spiral shaped bacteria with a flagella at both ends

3. Bacilli

4. Cocci

5. Spirilla

6. Archaea and Bacteria are Prokaryotes • Prokaryote is an organism that consists of a single cell that does not have a nucleus • All bacteria and archaea are single celled organisms and do not have a nucleus • Sometimes they stick together to form strands or films but they are still single functioning organisms.

7. Prokaryote Reproduction • Binary fission is a reproduction in which, one single-celled organism splits into two single-celled organisms. • There are 4 steps in Binary Fission • During binary fission a cells DNA is copied and bound to different places in the cell when the cell is double the original size it pinches off and a cell wall forms.

9. Endospores • An endospore contains genetic material and protein, and is covered by a thick protective coat • Many endospores can survive in hot, cold, and very dry places

11. The Domain Bacteria • Scientists think that bacteria have lived on the earth for over 3.5 billion years • Bacteria are in part classified by the way they get food • Consumers get food by eating other organisms • Decomposers feed on dead organisms • Producers make their own food

12. Cyanobacteria • Cyanobacteria are producers and usually live in the water • Cyanobacteria contain chlorophyll which is important to photosynthesis • Many have other pigments as well which help in photosynthesis, like blue pigment or red pigment (which give flamingos their pink color).

13. Domain Archaea • There are 3 main types of archaea • Heat lovers live in temperatures usually ranging from 60˚C - 250˚C. • Salt lovers live in environments that have high levels of salt like the Dead Sea or Great Salt Lake. • Methane makers give off methane gas and live in swamps and animal intestines. • They live in

14. Harsh Environments • Archaea often live where nothing else can. • Most prefer environments where there is little or no oxygen. • Archaea are very different from bacteria. Not all have cells walls and when they do have them, they are very different from the cells walls of bacteria.