PRE-CLASS QUESTIONS for Week #9
(individual; open book; turn in July 15, 2008)
(lose 20% if turned in on July 16; 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. You have two one-million-gallon samples of water. One has a BOD of 30 ppm and the other a BOD of 5 ppm.

(a) It would be proper to discharge the BOD-30 sample into a river.
(b) It would be proper to discharge the BOD-5 water into a river.
(c) Both may be legally discharged into a river.
(d) Neither may be discharged into a river.
(e) The BOD-30 has more dissolved oxygen than does the BOD-5
(f) none of the above
Since water maximizes at 11 ppm oxygen. Dumping in BOD=5 would lower the oxygen level to 6 for awhile, but that wouldn't kill fish. The BOD-30 would instantly create a dead anoxic zone killing all aerobic forms of life.

  4. Pseudopodia are possessed by

(a) amoeba
(b) daphnia
(c) euglena
(d) paramecia
(e) pill bugs
(f) snails
The other single-celled things (b, c and d) have cilia or flagella. "e" has legs, and "f" has an undulating foot.

 2. Dr. Sevick collected a liter of water from the college pond. This water were thoroughly shaken to aerate it. 300 mL was then put into a bottle (#1) that was filled to the brim and capped. 700 mL of distilled water was added to the remaining and thoroughly shaken to saturate the contents with oxygen to 11 ppm (parts per million). 300 mL of that filled another bottle (#2) to the brim and capped. Once again the remainder was diluted in half with distilled water, shaken and used to fill a third bottle (#3), which was capped. All three bottles were stored away for 3 days before they were taken out and an electronic oxygen probe was inserted and the oxygen concentrations were taken.

#10 ppm     #25 ppm     #38 ppm

(a) The BOD = 2 ppm
(b) The BOD = 4 ppm
(c) The BOD = 8 ppm
(d) The BOD = 12 ppm
(e) The BOD = 16 ppm
(f) insufficient data
Bottle #2 used up 11-5=6 ppm; since it is half the concentration of #1, #1 must be 12 ppm..

 5. Which is true: plant chloroplasts

(a) do not have circular DNA they do
(b) do not have ribosomes they sure have
(c) do not convert H2O to elemental oxygen this is what it's all about!
(d) do not convert H2S to elemental sulfur
(e) do share mitochondria with the plant cell's cytoplasm no, they don't! Chloroplasts are actually prokaryotes and have no use for mitochondria.

 3. Which of the following is NOT true about euglena, paramecia AND amoeba:
(a) they are prokaryotes Nope! they are fully fledged members of the eukaryotes.
(b) they all possess ribosomes as do all organisms
(c) they all possess mitochondria as do all eukaryotic cells.
(d) only one occasionally possesses chloroplasts that's euglena which sometimes salvages the chloroplasts from the victims it eats.
(e) they are all aquatic these are.
 6. Regarding a secondary sewage treatment plant, the "secondary" phase is primarily for
(a) the removal of photosynthetic organisms
(b) eliminating BOD Secondary is highly aerobic encouraging microbes to rapidly convert BOD to CO2.
(c) adding either chlorine or ozone
(d) ridding the water of suspended solids such as silt, plastic drinking straws, leaves, twigs...
(e) removal of viruses
(f) adding good bacteria which will benefit the fish in the receiving river
(g) adding BOD