問題詳情
74. Restriction-modification systems:
(A) exist in all organisms as a protection against foreign DNA invasion.
(B) include a site-specific exonuclease to degrade foreign DNA.
(C) modify DNA by acetylation.
(D) include a DNA methylase and an endonuclease.
(E) include three types of endonuclease all of which cleave within a specific DNA target sequence.
(A) exist in all organisms as a protection against foreign DNA invasion.
(B) include a site-specific exonuclease to degrade foreign DNA.
(C) modify DNA by acetylation.
(D) include a DNA methylase and an endonuclease.
(E) include three types of endonuclease all of which cleave within a specific DNA target sequence.
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