MCQ: Environmental Microbiology 2nd

1. The biological oxygen demand (BOD) would be most directly affected by the presence of which of the following pollutants?
   a. Heavy metals            b. Organic wastes         c. Salt (Sodium chloride)          
   d. Waste minerals from mining   e. Fertilizer runoff from farms
2. The microorganisms that is mainly used as an indicator of fecal pollution in water is:
   a. Escherichia coli         b. Clostridium tetani      c. Clostridium botilinum
   d. Cyanobacteria                      e. All of these can be used
3. The worst water borne disease in U.S. was caused by:
   a. Escherichia coli         b. Salmonella typhi        c. Cryptosporidium parvum      
   d. Clostridium botulinum           e. None of these
4. Which of the following microorganisms are not derived from human pollution but can be found in water supply systems and are considered “nuisance” organisms?
   a. Coliform bacteria      b. Rhizobium    c. Azotobacter              d. Thiobacillus
   e. Clostridium
5. Biological treatment of sewage by microorganisms (mainly decomposers) would most likely occur at which stage of waste water treatment?
   a. Primary         b. Secondary    c. Tertiary         d. Advanced     e. All of these
6. Which of the following waste water treatments is most likely to produce carcinogens as a byproduct?
   a. Chlorination              b. Ozonation     c. Ultraviolet light (UV) d. Sand filtration           e. Carbon filtration
7. In order to prevent eutrophication of receiving waters, tertiary treatment is used to remove:
   a. Sulfate and nitrate     b. Phosphate and sulfate           c. Pathogenic bacteria
   d. Nitrate and phosphate           e. Excess oxygen
8. A major disadvantage of bioremediation is:
   a. Long times may be required              b. It is more expensive than other treatments
   c. It can not be used to treat contamination with hydrocarbons
   d. It requires removing contaminated soil to a bioreactor
   e. It requires introducing new microorganisms into an environment
9. The enzyme nitrogenase would most likely be found in:
   a. Nitrifying bacteria      b. Denitrifying bacteria  c. Nitrogen fixing bacteria
   d. Nitrogenase bacteria e. All of these
10. Free- living bacteria that are found in soil and can fix nitrogen are members of the genus:
    a. Nitrobacter   b. Rhizobium    c. Thiobacillus               d. Azotobacter            
    e. Clostridium
11. The most common microbiological contaminant of air is:
    a. Spores from bacteria             b. Spores from molds   c. Fungal hyphae
    d. Gram- positive bacteria         e. Gram negative bacteria.