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Study_questions_week-1_13

The safest vaccine virus with respect to preventing

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92): The safest vaccine virus with respect to preventing the vaccine virus from evolving inside a patient’s body to cause AIDS would be: A) The 20 passages virus B) The 40 passages virus C) An 80 passages virus that was identical to the 40 passages virus except that it had a mutated reverse transcriptase gene that was not transcribed in human CD4 + helper T-cells D) No expected differences between the 20 and 40 passage virus E) Both answers A & B are correct 93) Suppose that the 40 passages vaccine proved to be safe but instead of preventing infection by wild type HIV, it provided partial protection by doubling HIV’s generation time. If vaccinated people that became infected with wild type HIV were treated with AZT, the expected extension of their life would be A) about 20 years B) about 40 years E) no change expected 94) Suppose that HIV was able to recombine its genes in the same manner as influenza virus. Also suppose that you evolved 2 independent HIV vaccine viruses (after about 20 passages), one adapted to rhesus monkey cells (integration into chromosomes of CD4 + helper T-cells is blocked 99% of the time) and another adapted to howler monkey cells (reverse-transcription in human CD4 + helper T-cells is blocked 99% of the time). With respect to the vaccine virus itself causing AIDS, infecting a person simultaneously with both vaccines:
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95) Suppose that the vaccine was initially successful, but eventually the HIV virus in nature evolved resistance so that vaccinated people were no longer immune to the virus. If this resistance evolved a rate similar to that of antibiotic resistance, about how long would the vaccine remain useful?
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Use the following information for the next 5 questions (until you see a solid line): Some small invertebrates (like certain types of rotifers = minute aquatic multicellular organisms having a ciliated wheel-like organ for feeding and locomotion ) are strictly asexual and capable of producing anhydrobiotic eggs that dry to complete dehydration, with zero metabolism, and then come back to life upon rehydration. Two genotypes of haploid-annual-asexual rotifers ( genotype-R producing red eggs and genotype-G producing green eggs) were released (as anhydrobiotic eggs) during the spring into a remote small pond lacking rotifers. You can assume that only one gene in the genome codes for egg color and that adults die immediately after reproducing. The number of rotifer eggs released in the spring of generation-1 was 1 50 genotype-G and 50 genotype-R . The following summer the lake dried up but in the next spring before it refilled (the beginning of generation-2) all of the anhydrobiotic rotifer eggs produced from the previous year were collected and scored for color.
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