This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 71) After 1 year, those individuals in the control group that became infected with the HIV virus are expected to: A) Have far more bacterial infections compared to HIV-uninfected individuals B) Have a similar number of bacterial infections compared to HIV-uninfected individuals C) Have far fewer CD4 + helper-T cells compared to HIV-uninfected individuals D) Both answers A & C are correct E) None of these answers are correct 72) In individuals receiving the new drug (for the rest of their life), the addition of the drug AZT to the treatment: A) Would provide a second, independent line of defense against HIV B) Would provide no benefit over and beyond that already provided by the new drug C) Would make it more difficult for HIV to evolve resistance to the new drug D) Both answers A & C are correct E) None of these answers are correct 73) If the new drug was only partially effective and decreased the population size of HIV within an infected individual, then: A) The virus would stop evolving in drug-treated individuals B) AZT would have a longer benefit (compared to that in people not taking the new drug) C) The “escape hypothesis” predicts that the lifespan of HIV-infected individuals would be extended by the drug D) Both answers B & C are correct E) None of these answers are correct 74) Suppose that you observed that there was heritable variation among house flies for resistance to a pesticide, and that in environments where the pesticide is not used the lifetime fecundity of flies that were resistant to the pesticide was one offspring, and that of flies that were not resistant was ten offspring. Which statements are true: A) A policy of using the pesticide continuously every year would help to keep the pesticide effective B) Susceptibility to the pesticide would slowly decrease when it was discontinued C) A policy of using the pesticide in alternate years would help to keep the pesticide effective D) A policy of using the pesticide every year but only in some locations would help to keep the pesticide effective E) Answers C, and D are both correct 75) Characteristics of an influenza virus that would lower the probability of a new influenza outbreak are: A) Ability to block double infections of a single cell by the influenza virus B) Inability to block double infections of a single cell by the influenza virus C) Ability to infect a broad spectrum of birds and mammals D) Ability to infect a narrow spectrum of birds and mammals E) answers A, and D are both correct Use the following information for the next 5 questions (until you see a solid line): Suppose that a small haploid, asexual invertebrate (water flea) has an annual life cycle. It is transparent and lives in small pools (called vernal pools) that fill in the winter and then dry up during the summer. The water fleas persists by forming drought-resistant eggs when the pool begins to dry in late winter. These eggs hatch after the first major rain of the following winter. The water color of the vernal pools is clear at the start of each...
View Full Document
- Winter '07
- hiv virus, CD4+ Helper