Why are viroids resistant to nucleases?
A) Having a circular RNA "genome," they are resistant to most exonucleases (that digest the free ends of RNA or DNA).
B) Having a circular RNA "genome," with no protein shell, they are resistant to the protein-degrading activities of nucleases.
C) Nucleases will only digest DNA, not RNA, so viroids are protected.
D) Viroids have only been identified in plants. Plant nucleases cannot digest RNA.
E) Viroids are composed of single stranded RNA; nucleases only act on double-stranded molecules.

Question

Why are viroids resistant to nucleases?
A) Having a circular RNA "genome," they are resistant to most exonucleases (that digest the free ends of RNA or DNA).
B) Having a circular RNA "genome," with no protein shell, they are resistant to the protein-degrading activities of nucleases.
C) Nucleases will only digest DNA, not RNA, so viroids are protected.
D) Viroids have only been identified in plants. Plant nucleases cannot digest RNA.
E) Viroids are composed of single stranded RNA; nucleases only act on double-stranded molecules.

Quizplus · Accepted Answer

Viroids have a circular RNA genome, which makes them resistant to most exonucleases that typically digest the free ends of RNA or DNA. Viroids lack a protein coat, which makes them vulnerable to ribonucleases (RNases) that degrade RNA. However, the circular nature of their RNA protects them from exonucleases.

Why Are Viroids Resistant to Nucleases