R1E1T1R1O1V4I1R1U1S1
13 points
RETROVIRUS is validvalid
a virus made of RNA instead of DNA [n RETROVIRUSES]
any of a group of viruses whose genetic material is encoded in the form of RNA rather than DNA [n -ES]
a virus made of RNA instead of DNA [n RETROVIRUSES]
any of a group of viruses whose genetic material is encoded in the form of RNA rather than DNA [n -ES]