18.1 Studying Viruses and Prokaryotes

For more test practice,go to ClassZone.com.1.Set-up for Antibiotic TestingAntibiotic A B CInfected mice tested 30 15 5% Effectiveness 83% 25% 100%Scientists are testing three antibiotics—A, B,and C—on 50 mice with bacterial infections.Their experimental design is shown above. Theyconclude that they need to do more testing onantibiotic C becauseA it unexpectedly worked better than A and B.B 100 percent of the mice were cured.C the sample size was too small.D it will likely have the worst side effects.2. Impetigo is a highly contagious skin infectioncaused by staph or strep bacteria that arenormally found on the skin, where they areharmless. This infection is most likely tooccur whenA scraped skin provides the bacteria with accessto tissues they do not normally contact.B the bacteria have been genetically altered byscientists doing research.C the infected person did not receive regularlyscheduled vaccinations.D the bacteria form endospores on the surface ofthe skin.3. Some scientists think that measures of anecosystem’s health—such as usable nitrogenlevels in the soil—may become more variable asthe diversity of organisms on Earth declines.This is because usable soil nitrogen dependson a variety ofA animals that return nitrogen to the soilthrough respiration.B animals that return nitrogen to the soil afterthey die.C bacteria and other decomposers that fixnitrogen into a usable form.D plants, which produce nitrogen as a byproductof photosynthesis.4. The main reason that viruses are not consideredto be living things is that they do notA die when exposed to antibiotics.B reproduce on their own.C contain a nucleus.D undergo meiosis before replication.THINK THROUGH THE QUESTIONAll of these answer choices correctly describeviruses, so do not be tricked! Look at each answerchoice and try to think of a living organism thatfits the characteristic described, making thatanswer choice wrong.5. Hepatitis B is a viral disease that attacks cellsin the liver. When should a person receive avaccination against hepatitis B?A before being exposed to the virusB as soon as viral symptoms begin to appear.C after being diagnosed with the diseaseD never; the overuse of vaccines leads toantibiotic resistance6.??reproduceshasdoesn’tasexuallyhavenucleusDNAmembrane-boundorganelleschlorophyllWhich of the following is described by thisconcept map?A animal cellB plant cellC bacteriumD virusChapter 18: Viruses and Prokaryotes 571