PRE-CLASS QUESTIONS for Week #8
(individual; open book; turn in July 08, 2008)
(lose 20% if turned in on July 09; lose everything if turned in later!)

Grades will be curved providing you correctly answer at least 2 of these:
Put your answers on the answer sheet.

1. The principle function of "primary" sewage treatment
(a) elimination of pathogens
(b) elimination of dissolved organic compounds "secondary" treatment
(c) elimination of phosphates and nitrates tertiary ttttreatment
(d) elimination of odors Bah!
4. Bacterial genes can be moved between cells. Doing so employs various natural "tools." Which list below consists only of those tools?
(a) mesosomes and fimbriae
(b) virions and pili
(c) virions and transductases
(d) integrases and metasomes
(e) conjugases and metasomes

2. "BOD" relates to
(a) the amount of pathogens in waste water
(b) the amount of human body odor in waste water
(c) to amount of deleterious substances dissolved in waste water - including toxins, medicinals and hormones
(d) the amount of biodegradable organic compounds dissolved in waste water BOD = Biochemical/Biological Oxygen Demand: if there are rapidly biodegradable things in the water, the resident microbes will use dissolved oxygen to metabolize them, deplete the water of oxygen and fish, etc., die.
(e) the amount of phosphates or nitrates in the waste water
(f) the amount of O₂ which will fizz out of waste water upon heating quite the opposite!
5. Various processes are used by prokaryotes to move genetic material among their populations. Which list consists exclusively of those processes?
(a) conjugation, meiosis eukaryotes, subduction geology
(b) chiasma eukaryotes, conjugation, transduction
(c) conjugation, transformation, transduction
(d) excision, integration, segregation intracellular recombination processes; not intercellular!

3. Which of the following is NOT true:
(a) bacterial episomes consist of dsDNA
(b) within a given bacterial species, all pili are identical
(c) aerobiosis is more efficient than anaerobiosis
(d) Lactic-acid bacteria do not possess porphyrins and thus have no use for O₂
(e) E. coli, Salmonella spp. and Shigella spp. possess various "sexualities" including F⁺ and F^-
6. A culture medium containing DNase is inoculated with 1x10⁶ Staphylococcus aureus, which is easily killed by methacillin (this must be a sensitive strain - not MRSA!). To this culture is added one cell of MRSA. At timed intervals, 10 μL aliquotes are spread on NA plates containing methacillin. The next day colonies are counted on the plates. Which line on the following semi-log graph would indicate sexual (conjugation) transmission of the met^resistant gene.
Answer = "a". As meth-resistance is plasmid borne, it is transferred from cell to cell by conjugation converting sensitive recipients into resistant donors, which can then transfer the plasmid to other sensitive recipients, converting them into new donors, etc.