試題詳解

30. Which of the following represents a difference between viruses and viroids?
(A) Viruses contain introns; viroids have only exons.
(B) Viruses infect many types of cells, whereas viroids infect only prokaryotic cells.
(C) Viruses always have genomes composed of DNA, whereas viroids always have genomes composed of RNA.
(D) Viruses have capsids composed of protein, whereas viroids have no capsids.
(E) Viruses cannot pass through plasmodesmata; viroids can.