B. Correct! Bacillus anthraces produces spores that can cause anthrax. D. Incorrect! Diphtheria is caused by Corynebacterium diphtheriae.

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1 Microbiology - Problem Drill 09 - The Prokaryotes No. 1 of Bacillus anthraces is most closely associated with which of the following? (A) Botulism poisoning (B) Anthrax (C) Gangrene (D) Diphtheria Clostridium botulinum produces one of the most powerful toxins known. It is the cause of botulism food poisoning. Clostridium spores can be airborne and so can get into foods. When stored in anaerobic conditions such as cans or jars the spores germinate and the bacteria release their toxin. B. Correct! Bacillus anthraces produces spores that can cause anthrax. Clostridium bacteria may cause gas gangrene, about 80% of cases are due to Clostridium perfringens. Diphtheria is caused by Corynebacterium diphtheriae. Bacillus anthraces is an endospore forming, Gram-positive, facultative anaerobe, rod-shaped bacterium. It belongs to the genus Bacillus. B. anthraces is a natural soil-dwelling microbe, and causes anthrax. When it becomes environmentally stressed, B. anthraces produce endospores. When eaten by cattle, sheep, or other herbivores, the bacteria begin to reproduce and ultimately kill the animal. It will continue to reproduce in the carcass. When the nutrients are exhausted, new endospores are produced and the cycle repeats.

2 No. 2 of Clostridium botulinum is most closely associated with which of the following? (A) Botulism poisoning (B) Anthrax (C) Gangrene (D) Diphtheria A. Correct! Clostridium botulinum produces one of the most powerful toxins known. It is the cause of botulism food poisoning. Clostridium spores can be airborne and so can get into foods. When stored in anaerobic conditions such as cans or jars the spores germinate and the bacteria release their toxin. Bacillus anthraces is an endospore forming, Gram-positive, facultative anaerob4, rod-shaped bacterium. It belongs to the genus Bacillus. B. anthraces is a natural soil-dwelling microbe, and causes anthrax. Clostridium bacteria may cause gas gangrene, about 80% of cases are due to Clostridium perfringens. Diphtheria is caused by Corynebacterium diphtheriae. Clostridium botulinum produces one of the most powerful toxins known. It is the cause of botulism food poisoning. Clostridium spores can be airborne and so can get into foods. When stored in anaerobic conditions such as cans or jars the spores germinate and the bacteria release their toxin. Toxin causes muscular paralysis and blurred vision. Laboratory clues: Motile No terminal spores Non-aerotolerant Lipase +

3 No. 3 of In prokaryotes the type of reproduction that results in palisade arrangement is called: (A) Endospore formation (B) Pleomorphic division (C) Snapping (D) Binary fission Spore formation is the reproductive cell of actinomycetes and fungi and do not form palisade. Pleomorphic refers to a cell morphology that describes a variable shape not type of reproduction or division. C. Correct! Is a variation of binary fission. The daughter cell may stay attached at one end. Binary fission is a method of reproduction where the cells divide and separate. The diphtheriae bacteria divide by snapping and they form a V shape or side by side stacking called palisade

4 No. 4 of The most common anaerobic human pathogen? (A) Bacteroides (B) Spirochetes (C) Theremophiles (D) Chlamydia A. Correct! Bacteriods are the most common anaerobic human pathogen. Spirochetes cause syphilis and Lyme disease but are not the most common human pathogen. Theremophiles require extremes of temperatures that would not be conducive for human life. Chlamydia is causes infections of the human eye and genitals. It is one of the most common sexually transmitted diseases. Bacteroides are found in the intestine. Adapted to grow where there is no oxygen. Assist in breaking down nutrients and supply some vitamins and nutrients that humans cannot make. When bacteroides moves from the intestine medical problems can result. A common problem is the abscess. Bacteriods are the most common anaerobic human pathogen. Bacteroides can rapidly become resistant to antibiotics.

5 No. 5 of is best described as a stiff spiral shaped prokaryote. (A) Spirilla (B) Bacilli (C) Cocci (D) Legionella A. Correct! Spirilla is spiral shaped but in addition is stiff. Shape pointed, spindle or filamentous. Shape: Spherical (some variation), kidney or oval. Legionella shape is that of bacilli. Spiral spiral: stiff (spirilla) Spirochetes: flexible Slightly curved: vibrios Spiral

6 No. 6 of Which does not describe endospores? (A) Can stay alive a very long time. (B) A form of reproduction in harsh conditions. (C) Form during harsh environmental conditions, not for reproduction. (D) All prokaryotes can form endospores under the right conditions. They can stay alive for decades. They do form under harsh conditions but they are not a form of reproduction. C. Correct! Endospores do form in response to harsh environmental conditions but are not a form of reproduction. Not all prokaryotes have the capacity to form endospores. Endospores do form in response to harsh environmental conditions but are not a form of reproduction.

7 No. 7 of Which of the following is not an arrangement of cocci? (A) Tetrads (B) Sarcina (C) Streptococci (D) Streptobacilli Tetrads is a function of cocci division in two planes. Sarcina is a function of cocci division in three planes. Is a long chain of cocci. D. Correct! Streptobacilli are bacilli and so do not have a cocci shape. This is a schematic of the shapes that cocci assume. It is a function of the plane that the bacteria divide in, one, two multiple or random.

8 No. 8 of Archaea are distinguished from other bacteria by: (A) Have bacteria that can fix or reduce nitrogen. (B) AUG (methionine) is the initial amino acid in their polypeptide chains. (C) Have only Gram negative members. (D) Have peptidoglycan in their cell walls. Archaea and Proteobacteria have nitrogen fixers. B. Correct! The initial amino acid in the polypeptide chain methionine) is coded with AUG start codon. Members of the bacteria Phylum can be Gram-negative or Gram-positive. Archaea does not have peptidoglycan in their cell walls. Archaea lack peptidoglycan in their cell walls. Their cell membrane lipids are branched hydrocarbon chains. The initial amino acid in the polypeptide chain methionine) is coded with AUG start codon.

9 No. 9 of Deeply branching bacteria are named because? (A) There are many and diverse members in their group. (B) Based on gene analysis it is believed that they are similar to the earliest bacteria. (C) They are heterotrophic. (D) Low growth temperature. Bacteria as a whole are extensively diverse. B. Correct! Based on rrna sequences it is believed that these bacteria branched early from the original bacteria. Deeply branching bacteria are autotrophic. They have varied growth temperatures. Deeply branching bacteria are believed to come from the earliest living microbes, with the least amount of evolutionary change. Based on genetics, rrna sequencing they are thought to be more related to early microbes then to more evolutionarily advanced microbes and organisms. The significance of this is that it can provide some insight into what the environment was like at the time they evolved. This is because these organisms would have responded to the current environment.

10 No. 10 of Which of the following statements is incorrect with respect to mycoplasmas? (A) Are the smallest free living cells. (B) They are considered pleomorphic. (C) In culture form a fried egg appearance. (D) Have a pliable cell wall to change their structure. Mycoplasmas have the smallest free living cells in their group. Because of the lack of cell wall they can change shape, hence they are pleomorphic. When cultured in the laboratory they do form the shape of a fried egg.. D. Correct! Mycoplasmas do not have a cell wall. Mycoplasma is a genus of the smallest free living microorganisms and do not have a cell wall. They can be parasites or saprophytic (getting its nutrients from decaying plant or animal matter). Several species are pathogenic to humans including and can cause pneumonia and pelvic inflammatory diseases. They are resistant to antibiotics that target cell wall synthesis like penicillin.