Which of the following represents a difference between viruses and viroids?
B) Viruses have capsids composed of protein, whereas viroids have no capsids.
C) Viruses contain introns, whereas viroids have only exons.
D) Viruses always have genomes composed of DNA, whereas viroids always have genomes composed of RNA.
E) Viruses cannot pass through plasmodesmata, whereas viroids can.
Answer: B