18.4 Bacteria and Archaea Kingdom Eubacteria Domain Bacteria PDF
Preview 18.4 Bacteria and Archaea Kingdom Eubacteria Domain Bacteria
18.4 Bacteria and Archaea Kingdom Eubacteria Domain Bacteria 18.4 Bacteria and Archaea Description Bacteria are single-celled prokaryotes. 18.4 Bacteria and Archaea Where do they live? Prokaryotes are widespread on Earth. ( Est. over 1 billion types of bacteria, and over 1030 individual prokaryote cells on earth.) Found in all land and ocean environments, even inside other organisms! 18.4 Bacteria and Archaea Common Examples • E. Coli • Tetanus bacteria • Salmonella bacteria • Tuberculosis bacteria • Staphylococcus • Streptococcus 18.4 Bacteria and Archaea Modes Of Nutrition • Bacteria may be heterotrophs or autotrophs 18.4 Bacteria and Archaea Bacteria Reproduce How? • by binary fission. • exchange genes during conjugation= conjugation bridge increases diversity. • May survive by forming endospores = specialized cell with thick protective cell wall. TEM; magnification 6000x • Can survive for . centuries until environment improves Have been found in mummies! 18.4 Bacteria and Archaea • Bacteria Diagram – plasmid = small piece of genetic material, can replicate independently of the chromosome – flagellum = different than in eukaryotes, but for movement – pili = used to stick the bacteria to each other or surfaces pili plasma membrance flagellum chromosome cell wall plasmid This diagram shows the typical structure of a prokaryote. Archaea and bacteria look very similar, although they have important molecular differences. 18.4 Bacteria and Archaea • Classified by: their need for oxygen, how they gram stain, and their shapes 18.4 Bacteria and Archaea Main Groups by Shapes – rod-shaped, called bacilli – spiral, called spirilla or spirochetes – spherical, called cocci Spirochaeta: spiral Lactobacilli: rod-shaped Enterococci: spherical 18.4 Bacteria and Archaea • Main Groups by their need for oxygen. • obligate anaerobes are poisoned by oxygen - Ex. Clostridium botulinum - Ex. Clostridium tetani – obligate aerobes need oxygen - Ex. Mycobacterium tuberculosis – facultative aerobes can live with or without oxygen - Ex. E. Coli
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