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True or False: The plasma membrane and most other membranes are composed of a lipid bi-layer in which integral proteins are buried. ✔✔True True or False: Procaryotic cells are usually smaller than eucaryotic cells. ✔✔True True or False: Most procaryotes have strong cell walls that give them shape. ✔✔True The significance of the plasma membrane is that: A) It selectively allows some molecules to pass into the organism B) It prevents movement of molecules out of the organism
C) It is the site of protein synthesis
B) Self-replicating segment of single stranded RNA C) A bacterial chromosome ✔✔A, self-replicating segment of double stranded DNA Bacteria do not always swim aimlessly but are attracted by such nutrients, such as sugar and amino acids, and are repelled by harmful substances and bacterial waste products. Movement toward chemical attractants and away from repellents is called: A) Gliding motility B) Tumbling C) Chemotaxis ✔✔C, chemotaxis Some bacteria are considered pleomorphic. This means: A) They are shaped like bent rods B) They have a corkscrew shape C) They do not have just one shape D) They are either bacilli or cocci ✔✔C, they do not have just one shape
Poly-beta-hydroxybutyrate inclusion bodies: A) Protect bacteria from excessive drying B) Store carbon for energy and biosynthesis C) Turn reddish brown when stained with iodine D) Are composed of polymers of glucose ✔✔B, store carbon for energy and biosynthesis Gas vesicles in bacteria: A) Help move cells to optimal nutrient levels B) Store oxygen for growth anaerobically C) Are bounded by a lipid bi-layer membrane D) Are bounded by a membrane impervious to gas ✔✔A, help move cells to optimal nutrient levels Another common bacterial shape is that of a rod, often called:
C) Have a thick capsule that traps the crystal violet stain D) Have a periplasmic space that traps the crystal violet stain ✔✔B, have multiple layers of peptidoglycan that help retain the crystal violet stain Gram positive cells: A) Have thick, homogeneous cell walls B) Have large amounts of teichoic acids C) Do not have an outer membrane D) All of the above are true ✔✔D, all of the above are true The outer membrane of Gram negative cells is more permeable than the plasma membrane because: A) LPS is larger than most membrane phospholipids B) Lipoproteins stretch the outer membrane
C) Porin proteins establish holes in the outer membrane D) The core polysaccharide spans the lipid bi-layer ✔✔C, porin proteins establish holes in the outer membrane The most important role of the prokaryotic cell wall is to: A) Maintain the shape of the cell B) Protect the cell from osmotic pressures C) Prevent ions for diffusing away from the cell D) Block the effects of antibiotics like penicillin ✔✔B, protect the cell from osmotic pressures Which of the following is NOT true about capsules and slime layers? A) They consist of secreted material lying outside of the bacterial cell wall B) They can prevent desiccation of bacteria cells C) They are required for bacteria to grow normally in culture
Which of the following is NOT true about bacterial flagella? A) Most of their length consists of a hollow, rigid protein tube B) They are constructed largely of a single protein called flagellin C) They spin like wheels, either clockwise or counterclockwise D) They use ctyoplasmic ATP as their primary energy source ✔✔D, they use cytoplasmic ATP as their primary energy source The flagellar filament grows by: A) Enzymatic addition of subunits to the top of the flagellum B) Enzymatic addition of subunits to the base of the flagellum C) Self-assembly of subunits traveling through the hollow flagellum to the tip D) Self-insertion of subunits along the length of the filament ✔✔C, self-assembly of subunits traveling through the hollow flagellum to the tip
How does a bacterium control the direction of swimming? ✔✔The bacterium does not control the direction of its swimming What is the purpose of bacterial endospores? A) Allow the bacterium to makes hundreds of "seeds" to spread on the wind B) Help the bacterium differentiate into faster growing stages of bacteria C) Allow the bacterium to survive the absence of oxygen D) Allow the bacterium to survive extended periods of heat of dryness ✔✔D, allow the bacterium to survive extended periods of heat or dryness Plasmids are important to the genetics of many bacteria. This is because: A) They are inherited from one generation to the next B) They may carry genes that give their host a selective advantage C) They can render bacteria drug-resistant D) All of the above ✔✔D, all of the above
"Spontaneous generation" is the hypothesis that microorganisms are agents of human disease. ✔✔False True or False: In his studies on fermentation, Louis Pasteur presented the first evidence that some microorganisms could grow anaerobically (in the absence of oxygen). ✔✔True True or False: Most microbiologists study infectious disease. ✔✔False True or False: The primary difference between Koch's original postulates and the "molecular" Koch's postulates is that instead of the presence or absence of a particular microorganism, we consider whether a particular virulence gene is present and active. ✔✔True True or False: Sergei Winogradsky and Martinus Beijernick demonstrated that microbes have an essential role in the fixation of atmospheric nitrogen into usable nitrates. ✔✔True
Which event came first? A) Koch demonstrates that a bacterium, Anthrax, can cause disease B) Fizeau measures the velocity of light ✔✔B, Fizeau measures the velocity of light Which event came first? A) Avery demonstrates that DNA carries genetic information B) World War II begins ✔✔B, World War II begins Which event came first? A) Watson and Crick describe DNA double helix B) First hydrogen bomb exploded ✔✔B, first hydrogen bomb exploded Which event came first? A) Lyme disease discovered
Who first suggested using the thickening agent most commonly used for colony purification today? ✔✔Frannie Hesse Credit for the first vaccine for the prevention of human disease is generally given to: A) Edward Jenner for the prevention of small pox B) Louis Pateur for the prevention of rabies C) Louis Pasteur for the prevention of anthrax D) Rober Koch for the prevention of tuberculosis ✔✔A, Edward Jenner for the prevention of small pox When Louis Pasteur first tried his vaccine on a young boy, there was a possibility that the vaccine itself could kill the child. This was permissible under the standards of the day because: A) The importance of science was worth the risk B) Less value was placed on human life than today C) The child was from a poor family
D) The child had rabies, which was always fatal ✔✔D, the child had rabies, which was always fatal Agostino Bassi first showed that a disease, in silkworms, was caused by a microorganism. What kind of microorganism caused the disease? ✔✔Fungus What was the first bacterium shown to cause human disease? A) Anthrax B) Mycobacterium C) Diphtheria D) Streptococcus ✔✔A, anthrax What was the first virus shown to cause disease? A) Polio B) Hepatitis
D) Observation of phagocytosis of bacteria ✔✔B, injection of rabbit "antitoxin" to protect against diphtheria The first physician to make practical application of the germ theory of disease to surgery was: A) Louis Pasteur B) Robert Koch C) Joseph Lister D) Edward Jenner ✔✔C, Joseph Lister The initial classification of bacterial isolate is dependent upon multiple factors. Which of the following factors is not used in the initial classification of an isolate? A) Shape of cells B) Arrangement of cells C) Staining characteristics D) Rate of growth/division of cells ✔✔D, rate of growth/division of cells
Bacterial cells that exhibit an intermediate shape between rods and cocci are called: A) Spirilla B) Vibrios C) Coccobacilli D) Spirochetes E) Pleomorphic ✔✔C, coccobacilli Bacteria of which shape, rarely remain attached after division and are usually only seen as single cells? ✔✔Spiral Cell division of cocci in several places produces a arrangement. A) streptococcal B) staphylococcal C) streptobacilli ✔✔B, staphylococcal
