• 2022-05-30
    Which
    of following can cause the great variation of influenza virus and
    wide epidemic:()
    A: gene
    reassortment
    B: gene
    recombination
    C: transduction
    D: transformation
    E: conjunction
  • A

    内容

    • 0

      The<br/>transfer of genetic material between bacteria in direct physical<br/>contact is called() A: conjugation B: transformation C: transduction D: lysogenic<br/>conversion E: mutation

    • 1

      Which<br/>of the following character about the pathogenesis of measles virus is<br/>wrong ( )? A: causing<br/>viremia twice B: transmitted<br/>through respiratory tract or contact C: most<br/>are inapparant infection D: Koplik’s<br/>spot is helpful in early diagnosis E: can<br/>infect central nervous system

    • 2

      Which<br/>of the following virus structure is derived from host cell membranes() A: nucleic<br/>acid B: capsid<br/>protein C: lipid<br/>bilayer D: sugar<br/>in spikes E: protein<br/>in spikes

    • 3

      Which<br/>one of following is most accurate?() A: HCV<br/>is transmitted through blood,but HDV not B: Both<br/>HBV and HCV can establish a chronic carrier state C: There<br/>is an effective vaccine against HCV but not against HDV D: Both<br/>HCV and HDV are defective virus E: Both<br/>HCV and HDV can be cultured artifially

    • 4

      Control of gene expression<br/>by preventing a gene from being expressed. () A: Transcription B: Induction C: Translation D: Replication E: Repression