The infectious agents described are viroids, which were discovered by T.O. Diener in 1971. They are characterized by several unique features:

Low Molecular Weight RNA: They consist entirely of a short, single-stranded circular RNA molecule with low molecular weight.

Lack of Protein Coat: Unlike viruses, viroids lack a protein coat (capsid).

Absence of Peplomers: Since viroids lack any protein or envelope structure, they do not possess peplomers (the spike-like glycoproteins found on the envelopes of some viruses).

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