You and your friends are hiking the Appalachian trail in North Carolina. You run out of water and your friends want to fill up from a beautiful clear stream in the middle of the forest. What precautions should you take before drinking the water and why?
What will be an ideal response?
Answer: The most common disease that can be contracted from drinking untreated surface water in North America is giardiasis, caused by Giardia intestinalis. Even the most pristine water can contain Giardia cysts as wildlife such as beavers and muskrats carry the pathogen. Water should be filtered and disinfected with iodine or chlorine OR should be filtered and boiled. Camping stores carry filtering equipment and chemicals that are certified to remove or kill pathogens and make surface water safe for drinking.
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Eukaryotes, archaeons, and bacteria can all successfully oxidize H2S or NH4 to form SO4 or N2, respectively
A. true B. false
Following the Deepwater Horizon accident in the Gulf of Mexico in 2010, bioremediation was used to eliminate much of the oil from the contaminated water. To encourage the growth of oil-degrading microbes, "fertilizer" including iron and nitrogen was added to the water. Which of the following statements regarding the growth of these microbes is incorrect?
A. The oil-degrading microbes used oil (hydrocarbons) as their carbon source. B. The concentration of sulfate in the Gulf of Mexico is sufficient for the growth of oil-degrading microbes. C. Large amounts of iron were needed, as iron is a macronutrient for oil-degrading microbes. D. Nitrogen gas (N2) present in air is not in a form that can be used by oil-degrading microbes.
A viral lytic cycle is characterized by:
a. rapid infection and emergence. b. rapid infection, replication of nucleic acids and proteins, assembly of virions and release by rupture. c. a virus remaining in the host cell then being released. d. a viral nucleic acid being inserted into the host genome and possibly residing through multiple cell divisions prior to lytic.
Which of the following sequences of events in the production of recombinant DNA are in the correct order?
A. cut DNA with restriction enzymes, mix DNA with plasmid DNA, add DNA ligase B. mix DNA with plasmid DNA, cut with restriction enzymes, add DNA ligase C. add DNA ligase, cut DNA with restriction enzymes, mix DNA with plasmid DNA D. mix DNA with plasmid DNA, add DNA ligase, cut with restriction enzymes E. cut with restriction enzymes, add DNA ligase, mix DNA with plasmid DNA