AMycoplasma
BRickettsia
CViroid
DActinomycete
Answer:
C. Viroid
Read Explanation:
Viroids are infectious pathogens that affect only plants, therefore are also called plant pathogens.
Structurally, viroids are smaller than viruses and possess circular strands of ribonucleic acids (RNAs) with no protein coating.
These entities hijack the cellular machinery present in plant cells to replicate new copies of themselves.
It primarily affects all forms of higher plants.
Some of the characteristic features of viroids are given below:
Viroids contain only RNA.
These are known to be smaller in size and infect only the plants.
These are among the smallest known agents causing infectious disease.
Viroids are species of nucleic acid with relatively low molecular weight and a unique structure.
They reproduce within the host cell which they affect and cause variations in them causing death.
Viroids are mainly classified into two families namely Pospiviroidae- nuclear viroids and Avsunviroidae- chloroplastic viroids.
Viroids are said to move in an intracellular manner, cell to cell through the plasmodesmata, and long distance through the phloem.