The walls of bacteria can be either ___________ or ______________.  Some produce a slime layer known as a _____________________.  This structure protects the bacterium from the immune system.  Bacteria may also be classified as ____________________ or ____________________ based on their colors after a Gram stain.  Those that are ________________ stain purple because of a thick peptidoglycan layer in the cell wall (treat these with pencillin).  Those that are __________________ stain pink because the outer membrane is removed by the alcohol rinse & the peptidoglycan layer allows the dye to leave (treat these with tetracycline). Bacteria contain many ribosomes & _________________ that are small segments of DNA.  Some bacteria may have flagella while others may have ____________ resemble cilia.  These allow the bacteria to attach to food.  Some bacteria are _________________ while others cannot move.  Some bacteria are __________________ while others make their own food & are therefore considered to be __________________.  Some bacteria are ____________________ which means they feed on dead organisms.  Those bacteria that require oxygen to live are called _________________________________.  An example is ____________.  Those that can survive without oxygen are termed _______________________________.  An example is ______________.  Those that can live with or without oxygen are termed __________________________.  An example is ____________________. A ________________ is a large group of bacteria living together.  All members are descendants of a single bacterium. Some bacteria form ___________________ when conditions are harsh.  The bacterium makes a membrane around itself when food or nutrients become low.  The membrane wraps around one strand of ________ & some __________________ & becomes dormant. Most bacteria can reproduce at a rate of every _______________________.  This occurs through the process of _____________________ usually, but may also occur through the process of ______________.  In this process a donor bacterium transfers genetic material to an acceptor bacterium through direct contact. PROKARYOTES  VS.    EUKARYOTES No nucleus      nucleus present Little internal organization in cytoplasm   internal organization present Small – 1 um       large Always unicellular     Can be uni- or multicellular Chromosome = single circular piece of DNA  Chromosome = linear pieces of DNA Reproduction usually by binary fission   Reproduction by mitosis or meiosis Corkscrew-like flagella     Whip-like flagella Anaerobic or aerobic     Aerobic only BACTERIA IN NATURE Bacteria help the ecosystem recycle nutrients.  Because they break down materials, they are known as ____________________.  They play a significant role in sewage treatment.  Bacteria also are involved in ____________________________ , a process where they convert nitrogen into a form plants can use.  Humans also use bacteria to produce _________, ____________, ____________, & ________________.  COMMON BACTERIAL DISEASES Bubonic Plague – Cholera – Dental Caries – Dysentery – Lyme Disease – Typhoid Fever – Tuberculosis – Syphilis – Botulism – Strep Throat – Tooth Decay – Tetanus – Salmonella – Pneumonia -