Micro Exam 2

. An agent used to reduce the number of bacteria on a toilet would most accurately be called a(n) A) disinfectant. B) antiseptic. C) aseptic. D) fungicide. E) virucide.

A

24. Escherichia coli belongs to the A) proteobacteria. B) gram-positive bacteria. C) green sulfur bacteria. D) spirochetes. E) actinomycetes.

A

54. The term aerotolerant anaerobe refers to an organism that A) does not use oxygen but tolerates it. B) is killed by oxygen. C) tolerates normal atmospheric nitrogen gas levels. D) requires less oxygen than is present in air. E) requires more oxygen than is present in air.

A

A strictly fermentative bacterium produces energy A) by glycolysis only. B) by aerobic respiration only. C) by fermentation or aerobic respiration. D) only in the absence of oxygen. E) only in the presence of oxygen.

A

Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of A) osmotic lysis. B) inhibition of molecular transport. C) decreased synthesis of plasma membrane. D) cell shrinkage.

A

Gram positive bacteria can be broadly divided into A) High and low G+C B) Proteo and nonproteobacteria C) Extremophiles D) Archea

A

The biosafety level (BSL) for most introductory microbiology laboratories is A) BSL-1. B) BSL-2. C) BSL-3. D) BSL-4.

A

Which of the following structures is NOT found in some prokaryotic cells? A) flagellum B) axial filament C) cilium D) pilus E) peritrichous flagella

C

The definition of lysogeny is A) phage DNA is incorporated into host cell DNA. B) lysis of the host cell due to a phage. C) the period during replication when virions are not present. D) when the burst time takes an unusually long time. E) attachment of a phage to a cell.

A

Which of the following bacteria is gram-negative? A) E.coli B) Corynebacterium C) Bacillus D) Staphylococcus E) Mycobacterium

A

Which of the following describes oxidation of a molecule: a) loss of an electron by the molecule b) loss of water by the molecule c) transfer of a phosphate group to the molecule d) splitting of the molecule e) gain of a hydrogen by the molecule

A

Which of the following pairs of terms is mismatched? A) bacteriostatic — kills vegetative bacterial cells B) germicide — kills microbes C) virucide — inactivates viruses D) sterilant — destroys all living microorganisms E) fungicide — kills yeasts and molds

A

You have isolated a prokaryotic cell. The first step in identification is a(n) A) Gram stain. B) lactose fermentation test. C) endospore stain. D) flagella stain. E) DNA fingerprint.

A

. Which of the following lacks a cell wall? A) Borrelia B) Mycoplasma C) Mycobacterium D) Clostridium E) Nocardia `

B

12. The terms "run" and "tumble" are generally associated with A) cell wall fluidity. B) taxic movements of bacteria in response to attractants or repellents. C) clustering properties of certain rod-shaped bacteria. D) cell membrane synthesis.

B

75. In Figure 5.8, the path labeled "2" is the flow of A) electrons. B) protons. C) energy. D) water. E) glucose.

B

A culture medium consisting of agar, peptone, and beef heart is a A) chemically defined medium. B) complex medium. C) selective medium. D) differential medium. E) reducing medium.

B

A viroid is a(n) A) complete, infectious virus particle. B) infectious piece of RNA without a capsid. C) capsid without nucleic acid. D) provirus. E) infectious protein.

B

A virus's ability to infect an animal cell depends primarily upon the A) host cell's ability to phagocytize viral particles. B) presence of receptor sites on the cell membrane. C) type of viral nucleic acid. D) enzymatic activity of a host cell. E) presence of pili on the host cell wall.

B

An infectious protein is a A) bacteriophage. B) prion. C) retrovirus. D) viroid. E) papovavirus.

B

Azospirillum A) is Gram positive B) Fixes nitrogen and associates with plant roots C) Does not have cell wall D) is an archea

B

In Figure 4.3, which diagram of a cell wall is a gram-negative cell wall? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

B

In Figure 4.3, which diagram of a cell wall is resistant to many antibiotics (e.g., penicillin)? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

B

The majority of the bacteria in natural environment A) Can be grown in the lab B) Difficult to culture in the lab C) Form spores D) Are not alive

B

The mechanism whereby an enveloped virus leaves a host cell is called A) transduction. B) budding. C) abduction. D) lysogeny. E) penetration.

B

Which of the following is NOT utilized to culture viruses? A) laboratory animals B) culture media C) embryonated eggs D) animal cell cultures E) bacterial cultures

B

Which of the following is an advantage of the standard plate count? A) can readily count cells that form aggregates B) determines the number of viable cells C) can be performed on very dilute samples, such as lake water D) provides immediate results E) can be used to count heat-sensitive bacteria

B

Which of the following is an example of a metabolic activity that could be used to measure microbial growth? A) standard plate count B) glucose consumption C) direct microscopic count D) turbidity E) most probable number (MPN)

B

Which of the following is the best definition of oxidative phosphorylation? A) Electrons are passed through a series of carriers to O2. B) A proton gradient allows hydrogen ions to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP. C) ATP is directly transferred from a substrate to ADP. D) Electrons are passed through a series of carriers to an organic compound.

B

Which of the following organelles most closely resembles a bacterial cell? A) nucleus B) mitochondrion C) Golgi complex D) vacuole E) cell wall

B

Which of the following pairs of microbe classification terms and optimal growth temperatures is mismatched? A) psychrotroph — growth at 0°C B) thermophile — growth at 37°C C) mesophile — growth at 25°C D) psychrophile — growth at 15°C

B

Which of the following statements is TRUE? A) Endospores are made by all bacteria. B) Endospores allow a cell to survive environmental changes by producing a dormant period with no growth. C) Endospores are easily stained in a Gram stain. D) A cell produces one endospore and keeps growing.

B

Which one of the following organisms has a cell wall? A) Human cells B) fungi C) L forms D) mycoplasmas E) animal cells

B

. Which of the following is the best method to sterilize heat-labile solutions? A) dry heat B) autoclave C) membrane filtration D) pasteurization E) freezing

C

2. Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5% NaCl? A) Sucrose will move into the cell from a higher to a lower concentration. B) The cell will undergo osmotic lysis. C) Water will move out of the cell. D) Water will move into the cell. E) No change will result; the solution is isotonic.

C

A primary difference between cyanobacteria and purple and green photosynthetic bacteria is A) energy source. B) cell wall type. C) electron donor for CO2 reduction. D) cell type. E) color.

C

An example of intracellular pathogen transmitted through ticks A) E. coli B) Pseudomonas C) Rickettsia D) Salmonella

C

An example of opportunistic pathogenic bacteria that infects wounds and hospital instruments A) E.coli B) Salmonella C) Pseudomonas D) Rhizobium

C

Bacteria that insert DNA in plant genome and causes crown gall disease A) Salmonella B) E. coli C) Agrobacterium D) Rhizobium

C

By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration? A) simple diffusion B) facilitated diffusion C) active transport D) extracellular enzymes E) aquaporins

C

Oncogenic viruses A) cause acute infections. B) are genetically unstable. C) cause tumors to develop. D) are lytic viruses that kill the host cell. E) have no effect on the host cell.

C

The DNA found in most bacterial cells A) is surrounded by a nuclear membrane. B) utilizes histones for chromosomal packaging. C) is circular in structure. D) is linear in structure. E) is found in multiple copies.

C

Three cells with generation times of 60 minutes are inoculated into a culture medium. How many cells are there after 5 hours? A) 900 B) 180 C) 96 D) 32 E) 15

C

Where are phospholipids most likely found in a prokaryotic cell? A) flagella B) around organelles C) the plasma membrane D) ribosomes E) the plasma membrane and around organelles

C

Which of the following bacteria is gram-positive? A) Pseudomonas B) Salmonella C) Streptococcus D) Bacteroides E) Rickettsia

C

Which of the following is NOT required for the passive transport process? A) plasma membrane B) transporter proteins C) ATP D) concentration gradient E) aquaporins

C

Which of the following methods is used to preserve food by slowing the metabolic processes of foodborne microbes? A) lyophilization B) nonionizing radiation C) refrigeration D) ionizing radiation

C

57. Figure 6.2 shows a typical bacterial growth curve with the y-axis indicating the log of the number of bacteria and the x-axis indicating time in culture. In the figure, which section (or sections) shows a growth phase where the number of cells dying equals the number of cells dividing? A) a B) b C) c D) d E) a and c 58. In the figure 6.2 , which sections of the graph illustrate a logarithmic change in cell numbers? A) a and c B) b and d C) a and b D) c and d E) a and d

C B

. Alpha, beta and gamma bacteria are all A) proteobacteria B) Gram positive bacteria C) Gram negative bacteria D) Both A and C

D

50. Which of the following statements about viruses is FALSE? A) Viruses contain DNA or RNA but never both. B) Viruses contain a protein coat. C) Viruses use the anabolic machinery of the cell. D) Viruses use their own catabolic enzymes. E) Viruses have genes.

D

53. Salts and sugars work to preserve foods by creating a A) depletion of nutrients. B) hypotonic environment. C) lower osmotic pressure. D) hypertonic environment.

D

56. Most bacteria reproduce by A) aerial hyphae. B) fragmentation. C) mitosis. D) binary fission. E) budding.

D

73. Which of the following is NOT necessary for anaerobic respiration? A) cytochromes B) flavoproteins C) a source of electrons D) oxygen E) quinones

D

A Gram positive bacteria that forms endspore, is obligate anaerobe and causes disease A) E.coli B) Salmonella C) Bacillus D) Clostridium

D

A clear area against a confluent "lawn" of bacteria is called a A) phage. B) pock. C) cell lysis. D) plaque. E) rash.

D

All of the following are methods of food preservation EXCEPT A) desiccation. B) high pressure. C) ionizing radiation. D) microwaves. E) osmotic pressure.

D

An example of a bacteria that attacks other bacteria A) E.coli B) Salmonella C) Pseudomonas D) Bdellovibrio

D

Bacteria that form nitrogen fixing symbiosis with legumes A) Salmonella B) E. coli C) Agrobacterium D) Rhizobium

D

Enteric bacteria A) Inhabit the intestines B) Are Gram negative C) Are involved in food-borne diseases D) All of the above

D

How do all viruses differ from bacteria? A) Viruses are filterable. B) Viruses are obligate intracellular parasites. C) Viruses do not have any nucleic acid. D) Viruses are not composed of cells. E) Viruses do not reproduce.

D

Prokaryotes are composed of A) Bacteria B) Archea C) Fungi D) Bacteria and Archea

D

The difference between simple diffusion and facilitated diffusion is that facilitated diffusion A) moves materials from a higher to a lower concentration. B) moves materials from a lower to a higher concentration. C) requires ATP. D) requires transporter proteins. E) does not require ATP.

D

Which of the following is necessary for replication of a prion? A) DNA B) DNA polymerase C) lysozyme D) PrPSc E) RNA

D

1. Which of the following statements is INCORRECT regarding prokaryotic cells? A) Their DNA is not enclosed within a membrane. B) They lack membrane-enclosed organelles. C) They typically have a circular chromosome. D) They reproduce by binary fission. E) They lack a plasma membrane.

E

74. In Figure 5.8, where is ATP produced? A) a B) b C) c D) d E) e

E

Functions of the glycocalyx include all of the following EXCEPT A) biofilm formation. B) increased virulence. C) source of nutrition. D) protection against dehydration. E) binary fission (cell division).

E

How is ATP generated in the reaction shown in Figure 5.4? A) glycolysis B) fermentation C) photophosphorylation D) oxidative phosphorylation E) substrate-level phosphorylation

E

Which of the following is NOT an enteric bacteria? A) Salmonella B) Shigella C) Escherichia D) Enterobacter E) Campylobacter

E

Which of the following pairs is mismatched? A) spirochete — axial filament B) aerobic, helical bacteria — gram-negative C) enterics — gram-negative D) mycobacteria — acid-fast E) Pseudomonas — gram-positive

E

Which of the following statements is NOT true of lysogeny? A) It can give infected pathogens the genetic information for toxin production. B) Prophage is inserted into the host genome. C) Lytic cycle may follow lysogeny. D) It is a "silent" infection; the virus does not replicate. E) It causes lysis of host cells.

E

Microaerophile growth in the middle

OK

faculative growth is all throghout (D)

OK

14. In Figure 4.3, which diagram of a cell wall possesses lipid A/endotoxin (LPS) responsible for symptoms associated with infection? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

b

In Figure 4.3, which diagram of a cell wall is decolorized by alcohol? A) a B) b C) both a and b D) neither a nor b E) The answer cannot be determined based on the information provided.

b